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School of Women’s and Children’s Health, UNSW Medicine, Randwick, New South Wales, AustraliaSydney Children’s Hospitals Network, New South Wales, Australia
Correspondence and requests for materials should be addressed to Elizabeth E. Palmer, School of Women’s and Children’s Health, UNSW Medicine, Randwick, New South Wales 2031, Australia
School of Women’s and Children’s Health, UNSW Medicine, Randwick, New South Wales, AustraliaSydney Children’s Hospitals Network, New South Wales, Australia
Genetic testing is frequently conducted on people with intellectual disability. This systematic literature review sought to assess what research has been conducted with people with intellectual disability to investigate their opinions and experiences of genetic counselling and testing.
Methods
A search of 5 online databases (from year of database creation to 2021) yielded 1162 articles. Seven articles met the inclusion criteria. We assessed the quality, accessibility, and inclusivity of each study and extracted the data. Deductive content analysis was performed.
Results
Most study participants showed both the desire and the capability to learn more about genetic conditions and genetic tests. Participants expressed a wide variety of opinions about genetic tests, similar to the range of opinions of the general population. All studies were small and were from a limited number of countries, and analysis showed limited evidence of inclusivity or accessibility.
Conclusion
This review highlights major gaps in the understanding of the opinions, experiences, and preferences of people with intellectual disability regarding genetic counselling and testing. There is urgent need for research to codesign a more inclusive genomic model of care to address this failure in health care accessibility and equity.
Intellectual disability is a term for neurodevelopmental disorders that begin in childhood and are characterized by difficulties in conceptual, social, and practical areas of living.
The global prevalence of intellectual disability is around 10.37 per 1000 population with approximately 1.8% of the Australian population with a diagnosis of intellectual disability.
People with intellectual disability experience premature mortality and over-representation of potentially avoidable deaths caused by, eg, late diagnosis or mismanagement.
There is compelling evidence that many health care professionals overlook the basic needs of people with intellectual disability, eg, by excluding them from consultations, misattributing health problems to their disability, and sometimes displaying unprofessional and negative behavior.
Such noninclusive care practices can compromise the quality of health care offered to people with intellectual disability and contribute to poor health outcomes. A more inclusive model of care that actively involves this population at all stages of health service development and delivery has been shown to reduce existing health inequities and improve health care outcomes.
Intellectual disability can have both environmental and/or genetic causes. Genomics has revolutionized our understanding of the causes of intellectual disability, with a rapidly increasing number of underlying genetic causes identified (>2500).
Genetic testing, including chromosomal microarray and exome sequencing, is now recommended, on the basis of meta-analysis and multidisciplinary consensus statements, as a first-tier clinical diagnostic test for neurodevelopmental disorders, including intellectual disability, in many countries.
Meta-analysis and multidisciplinary consensus statement: exome sequencing is a first-tier clinical diagnostic test for individuals with neurodevelopmental disorders.
Consensus statement: chromosomal microarray is a first-tier clinical diagnostic test for individuals with developmental disabilities or congenital anomalies.
Meta-analysis and multidisciplinary consensus statement: exome sequencing is a first-tier clinical diagnostic test for individuals with neurodevelopmental disorders.
When studies that included the main indications for referral for genetic testing at individual diagnostic laboratories are considered, intellectual disability and/or global developmental delay are consistently the most frequent phenotypic indication for referral, eg, being given as the main indication for testing 20% to 30% of patients of any age and between 50% and 70% of patients under age 18 years.
Clarifying the underlying cause for individuals with genetically linked intellectual disability has the potential to improve health outcomes by facilitating surveillance of known complications of genetic disorders, enabling appropriate medical referrals, and, in a growing number of conditions, guiding the choice of specific therapies.
In contrast to this rapid rise in genetic testing for intellectual disability, genetic health professionals express uncertainty about the optimal means of providing genetic services to individuals with intellectual disability in an equitable and accessible manner. To meet this need, we conducted a systematic literature review to address the following 2 research questions:
1.
What are the experiences of people with intellectual disability of genetic counselling and testing?
2.
What are the opinions of people with intellectual disability about genetic counselling and testing?
We also sought to address whether any research conducted was performed in accordance with the best practice in inclusive and accessible research, ensuring that individuals with intellectual disabilities had an equal opportunity to participate in the research. Inclusive research is “research undertaken with people with intellectual disability, in ways which include them as actors” (ie, researchers), rather than as the subjects of research. Accessible research is “research which is accessible to and inclusive of people with intellectual disability,”
The final protocol was registered on Prospero (CRD42021260266).
Search strategy
We conducted a structured search using 5 electronic databases (Psychological Information Database [ProQuest], Web of Science, Scopus, Medical Literature Analysis and Retrieval System Online, and Cumulative Index of Nursing and Allied Health Literature). We applied a detailed review of indexing terms to identify suitable search terms and modified individual search strategies according to the database Medical Subject Headings/subject headings. We employed the following search strategy: (Intellectual disability) and (Genetic testing OR Genetic counselling) and (Patient education OR satisfaction OR attitude OR preference OR consent OR resource). The final search strategy included a combination of keywords and Medical Subject Heading terms related to the experiences and opinions of people with intellectual disability receiving genetic testing/counselling (Supplemental Table 1). We ran the final search on January 29, 2021 and included citations from the year the databases were created to maximize the potential of the search to find relevant articles.
Study selection
We exported citations using Endnote X7 (Thomas Reuters) and removed duplicates. After this, we imported and saved all articles in Covidence, which is a specialized software program for conducting systematic reviews.
Two of us (S.M.N. and E.E.P.) screened the titles and abstracts using Covidence to identify citations that related to the experiences and opinions of people with intellectual disability about genetic testing and counselling Table 1. We also extracted any citations that related to the experiences and opinions of individuals with the top 20 most prevalent genetic causes of intellectual disability as listed on the Orphanet database (https://www.orpha.net/consor/cgi-bin/index.php) to improve the detection of potentially relevant articles. Any conflicting decisions were discussed and resolved or moved to the next phase of the review process.
Table 1Inclusion criteria
Criterion
Explanation
Study population
People with intellectual disability; if studies included participants with different disabilities, only those studies for which 50% or more had an intellectual disability diagnosis were included
Study focus
Experiences, opinions, and resource needs of people with intellectual disability regarding genomic testing
Method
Qualitative and quantitative human studies
Publication type
Peer-reviewed reports of primary research
Publication language
English
Publication dates
From the year these databases were created to 2021.
We retrieved and reviewed full-text versions of peer-reviewed articles published in English that reported on the experiences or opinions of people with intellectual disability regarding genetic testing and/or counselling. We excluded articles that did not meet publication standards (eg, unpublished reports, dissertations, conference abstracts), articles that did not report on the genetic testing and counselling opinions and experiences of people with intellectual disability, and articles that were published in languages other than English.
All 4 authors independently reviewed full-text versions of the included articles, and decisions for excluding citations were recorded on Covidence. We manually searched the references of the included articles for additional relevant citations. We discussed any discrepancies regarding the inclusion or exclusion of undecided articles until consensus was reached.
Data charting process
We constructed a data extraction form using Excel to systematically extract variables. From each of the articles we extracted details, including the author names, year of publication, title, abstract, journal of publication, country of study, research design, number of participants/sample size, participant recruitment methods, and data collection methods. We also extracted information describing the study aims and any data related to the opinions or experiences of people with intellectual disability regarding the genetic counselling or testing process and information on the inclusivity and accessibility of the study design (Table 2). For example, a high degree of inclusivity would be shown if people with intellectual disability codesigned a research study or were part of the research team. Accessibility of the study would be shown if Easy Read information and consent sheets were used in study recruitment, if organizations for people with intellectual disability were consulted to facilitate recruitment and study processes, and if people close to the participants were available to ensure the participants were appropriately supported before, during, and after the study.
Table 2Methodology of the qualitative and quantitative articles included in this review
Author and Year of Publication
Country
Research Design
No of Participants (% Female, % Male); Age Range (Mean; SD)
Interviews or small group session (30-150 min). (Interviews transcribed by hand and reread for overt themes reported in order discussed during interviews, and for underlying themes)
No
Participants were not contacted through social or health services to emphasize confidentiality and to encourage a voluntary opt-in approach. A leaflet explaining the interview topics was distributed to obtain informed consent (not Easy Read)
No
Participants were interviewed in their home or college. Use of open questions to encourage free talking and to share control over topics, pace, and style. Aimed to establish mutual trust and respect.
Interviewer phoned participants a week after interview to check they “felt all right” about the interview and had nothing to add. Participants were sent transcripts and a short end of project report, asking if they wished to have details of published reports (no participants replied).
7 (29 male); Age range and mean age of participants in y not provided.
Down syndrome (1/7); Fragile-X syndrome (1/7); participants without a genetic diagnosis (5/7).
Two 1-day focus group workshops. (NA)
No
Each participant was visited before the workshops to explain the program fully and to give them the opportunity to decide whether or not to participate. Participation was restricted to participants who were known to be living in supportive environments and who were not experiencing any acute stresses in their personal lights.
Yes: preworkshop visits were arranged to find out who would be available to support participants both on the day and afterward, if necessary, and gave the trainers a chance to explain more about the workshops to supporters. Budget provided to allow professional help beyond that which could be offered by individual supporters. Local resources were also identified in case longer term counselling or support was required.
Decision to have workshops with a small number of participants to help them to explore and share their views. Attention was paid to making the workshop days as comfortable as possible, with a warm and welcoming venue, transport, and the kind of meals and breaks that participants had previously requested.
Yes: 4 of the participants decided to present at a knowledge exchange conference after the workshop and participants agreed among themselves which areas should be covered.
Mixed-methods; interviews with open and close-ended questions
43 (35 male). Age range 19-53 y; (28.8; 8.6).
WS (43/43)
Questionnaires including open and close-ended questions were administered during genetic counselling sessions. Postcounselling interview included closed and open questions. (Categorical: Fishers exact test, the McNemar test, or binomial test. Continuous data; Mann-Whitney U-test or Kruskal - Wallis test; responses to questions were coded independently, the codes used to classify the responses and the % of inter-coder agreement for coded responses provided.
No
Adult participants with a genetically confirmed diagnosis of WS attending a national Williams Syndrome Association Conference were invited to participate in the study. Informed consent (no further information) was obtained from 44 individuals of whom 1 later withdrew from the study
Postcounselling interviews occurred immediately after genetic counselling session.
28-item survey; study focused on the 6 closed-ended 5-point Likert scale items concerning the value of the definitive diagnosis. A comment section for each item offered opportunity to (1) describe in detail any aspect of their experience with 22q11.2DS and (2) provide context for Likert scale responses. (Descriptive statistics for Likert scales, non-parametric [Mann–Whitney U) or comparisons. SAS analyses used to determine statistical significance; content analysis to systematically code responses by hand and then studied using NVivo9 software (QSR International) to identify key themes).
No
Active recruitment through clinical services (all patients of adult 22q11 clinic). Informed consent (unclear if Easy Read).
No
Participants were mailed the study survey accompanied with a letter explaining aim of the study.
Staff member of grassroots organization who had Down Syndrome acted as a consultant to consider the feasibility and design of the study.
Recruitment facilitated through a local intellectual disability non-profit organization. 10 individuals were identified by members of the organization, chosen as were over 18, judged to have the receptive and expressive ability to take part in the interview, and had ongoing contact with the support organization. Information session was scheduled to have a preliminary discussion about the topic and provided information about the study. Information session led by first author and supported by members of the non-profit organization.
Yes: study conducted in partnership with local support organization. Initial information session held with invited participants, carers, and/or supporters.
Interviews conducted based on the personal preference of participants: either private space in the participants home or at their place of work.
Quantitative: observational, cross-sectional, multicentric study using questionnaire.
N = 953; (52 male); Mean age in y (43;15.3) However direct information only received from 361 individuals with intellectual disability.
Intellectual development disorders
Questionnaire. (Descriptive statistics, SPSS analyses, multi-variate analysis to test differences between groups, Binary logistic regression to find odd ratios for specific variables)
No
953 participants with intellectual developmental disorders were recruited to ensure a representative, randomized, and stratified sample.
Not reported
Not reported
Not reported
FDA, Foucaldian Discourse Analysis; IPA, Interpretative phenomenological analysis; NA, not applicable; WS, Williams syndrome.
Critical appraisal of individual sources of evidence
To minimize the risk of bias, we (I.S., S.M.N., and E.E.P.) independently assessed adequacy of the research methods and design and reliability and validity of the findings using the QualSyst tool (Supplemental Table 2). We rated the studies according to either qualitative or quantitative criteria. To ensure fairness in ratings, if the studies included both qualitative and quantitative elements but were not explicitly stated to be mixed methods, we evaluated the primary research design. The QualSyst scoring system contains 14 items to assess quantitative studies, with each item scored as 0 (no), 1 (partial), 2 (yes), or not applicable. The same ranking process is used to assess qualitative studies, which are rated on a scale containing 10 items. We rated the studies independently and then compared the assessments, resolving any discrepancies through discussion. Total summary scores were obtained for each study (Supplemental Table 2). No articles were excluded based on quality scores because of the relatively small number of articles that met the review inclusion criteria.
Data analysis and synthesis
The included studies were grouped by the primary methodology (qualitative vs quantitative), and the settings, populations, and study designs for each group were summarized along with the measures used and a summary overview of individual article findings (Table 2). The data extracted for quantitative studies included the effect size calculation, whereas for qualitative studies, we extracted illustrative quotes, participant reported experiences and/or opinions, and/or relevant themes. We also charted the inclusivity and accessibility of the study methodologies (Table 2). The research questions guided the identification of the following 4 key themes: (1) the experiences of people with intellectual disability receiving genetic testing, (2) the opinions of people with intellectual disability about genetic testing, (3) the resources available to people with intellectual disability, and (4) the extent to which the included studies were inclusive and accessible. These data are summarized in Table 3. We used deductive content analysis
To illustrate the perceptions and reproductive decisions of individuals with mild intellectual disability in the genetic counselling setting, 12 of whom were extensively interviewed as part of a Jane Engelberg Memorial Fellowship project to develop genetic counseling strategies for this population.
Participants expressed interest and desire to access available prenatal testing to prepare for their child. Participants reported that the possibility of identifying an inherited intellectual disability would not impact their reproductive plans.
Not directly reported (the interviewer was also providing the genetic counselling)
The counsellor believed that the early genetic process needs to address the counselee’s self-concept, attitudes toward disability, and level of reproductive motivation. This process established base for higher level decision-making.
Participants reported accurate understanding of inheritance risk. Participants expressed their desire to have children and took pride in their ability to parent. One participant expressed concern about the potential for her “not be allowed” to keep a baby. The ability of people with mild retardation [sic] to express their emotions and perceptions regarding genetic testing may not be hampered by their disability.
An exploratory study of the views of people who have Down syndrome about prenatal screening and cost, quality, and value of their lives.
Participants expressed varied opinions about prenatal screening—both for and against screening. Participants reported that individuals should have the option and the right to make their own informed decision about testing.
One participant who had received genetic counselling said that they understood having children was accompanied by various responsibilities, including getting married and a risk of having a child who might inherit their condition.
None
Participant reported positive attitudes when asked how they would feel when having a baby with Down syndrome.
To explore the perspectives of people with learning disability on the use of genetic information to inform choices around pregnancy.
Participants expressed a desire to access available testing to obtain information. Some participants reported that the fetus should be aborted if test shows learning disability to avoid being born into “a cruel world.”
Participants appreciated and understood issues relating to genetic information and choices in pregnancy. Participants supported education and informed decision-making for people with learning disabilities regarding genetic testing.
Topics covered in information sessions of workshops: Basic facts about babies and genes. Explanations about tests in pregnancy. Explanation about laws regarding abortion. Discussion about support required around having a test in a pregnancy. Methods included small group discussions and use of flip charts. Genes were explained as the bits of information on the sperm and egg that fit together like a jigsaw puzzle and help to determine what people are going to be like. The group talked about what might be on people’s genes and things that might “run in people’s families.” Back in small groups again, they drew or listed some things that might be “in their genes,” eg, “My bones, my height, a woman, my looks, asthma, my hair.” People wondered whether learning difficulties was “on a gene or not” and discovered that sometimes it was, and that this sometimes meant you could find out in advance whether your baby was going to have a learning difficulty before it was born.
Participants perceived it was important for people with learning disabilities to be involved in discussions about the use of genetic testing toward informing choices in pregnancy.
To determine if individuals with WS would be able to acquire basic information about the genetics of WS. To explore characteristics of individuals with WS that might influence whether they planned to have a child. To address participant satisfaction with a genetic counselling session.
Responses to question regarding if they would like to have option of genetic testing for WS: 79% yes, 16% no, and 5% unsure.
81% of participants reported that they had learnt something new in the genetic counselling session. 98% of participants reported that they would recommend genetic counselling to other individuals with WS.
The genetic counselling session included both verbal and visual information interspersed with both open and closed-ended questions. Homemade visual aides were included. Limiting the amount of information presented and using visual aids was helpful in communicating the factual information. The counsellor explained that a person’s chromosomes come from his/her mother and father and that WS occurs because a tiny piece of chromosome 7 is missing. The participant was told that the piece was missing at the very beginning of his/her mother’s pregnancy and that the missing piece could have come from either the mother or the father. The counsellor stressed the fact that the missing piece was no one’s fault. The participant also was told that he/she had a 50–50 chance to pass the chromosome with the missing piece to each of his/her children. The counsellor also told the participant that there was a test available that a pregnant woman could have to determine if the baby had WS before the baby was born.
When asked how they thought they would feel if they found out the baby had WS: 49% of participants reported that they would be okay or happy; 44% said they would be scared, sad, shocked, or upset; 7% indicated they did not know how they would feel. Participants receiving genetic counselling showed good understanding and retention of genetic risk information.
To survey adults with 22q11.2 deletion syndrome and their caregivers on their perceptions of the advantages and disadvantages of genetic diagnoses.
Participants with 22q11 deletion syndrome and their caregivers supported access to neonatal screening. Opinions on prenatal genetic testing not directly canvassed.
Participants reported genetic testing was beneficial because it gave a greater understanding and certainty, newfound sense of purpose and a platform for advocacy, and increased opportunities to optimize medical, social, and educational needs.
None
Participants’ quantitative and qualitative responses converged indicating a high degree of consistency. There was a high degree of consistency between participants with 22q11 deletion syndrome and their caregivers’ responses. A definitive molecular diagnosis of 22q11.2DS was perceived to be a critical event with diverse positive repercussions, even if occurring later in life.
To explore the perceptions and experience of individuals with Down syndrome of prenatal testing for Down syndrome.
Participants supported the right for prospective parents to have choice about prenatal testing for Down syndrome. Participants perceived genetic testing for Down syndrome positively because it provided parents with time to prepare for their child. Participants considered that it was important to have access to information about Down syndrome to support informed and balanced perceptions about disability.
No specific experiences with mainstream genetic services reported. Two of the individuals did not identify as having Down syndrome.
A prestudy information session was offered that included information on sex, reproduction, diversity, difference and disability, and testing for Down syndrome. Content prescreened by consultant with Down syndrome. Material was presented in verbal, written. and pictorial formats and series of activities to promote interaction and the assimilation of information. Summary booklet provided at the end of the session in written and pictorial versions.
Participants believed that they and any other people with Down syndrome could live a valued and valuable life with, and in spite of, impairment and a devalued label Participants felt that Down syndrome is viewed negatively due to lack of knowledge and education in parents and society in general. Participants reported a conflict between viewing themselves as wanted by their families but society viewing having a baby with Down syndrome as a “tragedy”
A total of 1162 articles were extracted after screening for English-only human studies. After abstract screening, 24 full-text articles were reviewed for inclusion, and 7 of those studies met the inclusion criteria. Two of us (S.M.N. and E.E.P.) independently extracted data from all 7 studies to ensure a consistent process. An interrater reliability of 100% was reached.
Selection of sources of evidence
Figure 1 summarizes the search process and reasons for citation exclusion.
Figure 1Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram. CINAHL, Cumulative Index of Nursing and Allied Health Literature; Embase: Excerpta Medica database; MEDLINE, Medical Literature Analysis and Retrieval System Online.
The citations for the 7 studies that met the inclusion criteria are summarized in Table 2 together with a summary of the included participants, methods and measures, and the measures reported in the study design that were consistent with an inclusive research approach. The 7 studies included 4 qualitative-only studies,
which used semistructured interviews, focus groups, or descriptive case reports, with a total of 23 individuals with intellectual disability. Of those 23 individuals, 14 had an identified genetic diagnosis: 13 people with a diagnosis of Down syndrome and 1 person with a diagnosis of Fragile X syndrome. Two mixed-methods studies, using both quantitative and qualitative analyses, were conducted with 43 adults with Williams syndrome
Finally, 1 quantitative study was conducted with individuals with intellectual disability; the total study size was 953 but direct information was only obtained from 37.95% of individuals with intellectual disability (other sources of information were health professionals, support workers, or family members), and thus, for the purpose of this study, the relevant sample size was 361.
Three of the studies were carried out in the United Kingdom, 2 in the United States, 1 in Spain, and 1 in Canada. Five studies were published in intellectual disability or social sciences journals and 2 in genetics journals. The quality of the 4 qualitative studies, assessed using QualSyst, was 0.7 (range = 0.55-0.95). The mean quality score of the 3 studies with quantitative elements, assessed using QualSyst, was 0.95 (range = 0.9-1) (Supplemental Table 2). The creators of the QualSyst tool have recommended a cut-off threshold of 0.75 for an article to be included in a systematic review.
Although 3 of the qualitative studies identified in our review scored below this threshold, the authors made a pragmatic decision to not exclude any articles based on the quality scores because of the sparsity of available literature on the experiences and opinions of people with intellectual disabilities regarding genetic counseling and testing and the need for qualitative and quantitative evidence synthesis for informing future health care policy.
What are the opinions of people with intellectual disability regarding genomic testing?
The main aim of 5 of the 7 studies was to explore the opinions of people with intellectual disability about prenatal genetic testing for Down syndrome,
A variety of opinions regarding genetic testing were expressed by participants across the studies, but in general, individuals showed support for freedom of choice for prospective parents to undergo prenatal testing for the relevant indication. When questioned, many participants were able to expand on the reasons why they considered it was good to have the option of prenatal genetic testing available. They suggested that this information could help parents prepare for the birth of a child who might have a disability and help check that the baby was going to be okay.
For example, Yvette (a 29-year-old woman with mild intellectual disability, presumed autosomal dominant) stated that she would like prenatal diagnostic tests in her next pregnancy “to make sure the baby is okay” and to prepare for the baby by getting handicapped tags (license plates) if the child has a physical disability.
Thinking about the option of prenatal genetic tests for intellectual disability was clearly distressing for some individuals. Philip (a 40-year-old man with Down syndrome) stated “Well it’s just about some of these things, they are too personal. I don’t want to talk about them to you or anyone.”
Five of the 7 studies asked the interviewees to imagine how they would feel if they were to undergo a prenatal genetic test and then find out that the unborn child has the same genetic condition as themselves. Participants expressed a range of opinions. A minority were uncertain; 7% of the individuals with Williams syndrome reported that they did not know how they would feel in this situation,
also expressed uncertainty about how he would feel.
When study participants could describe how they might feel in this hypothetical situation, a wide range of anticipated emotions were expressed. Some responses revealed that participants were not only thinking of how they might feel but also considering the viewpoint of the imagined child. For example, some described distress at the thought of the potential future stigmatization of their child.A 43-year-old woman with Williams syndrome stated “I would feel very shocked at first. It would take me time, a long time to explain to my child…. I would show the baby who she is, so she or he would really understand who they are first, to build their confidence, to let them know I am there for them and I would not walk away from them.”A 37-year-old woman with Williams syndrome stated “I’d probably feel a little sad. I know it has been hard for me. I’ve been going through you know poking, prodding, … having tests all my life. It would be sad for my kid for a while. And I’d have to tell my kid people are going to call you retarded, call you mean names.”
In contrast, others reported that they would feel joy or happiness if they found out that they were expecting a child with the same genetic condition as themselves. They often reflected on their own acceptance and indeed pride in their genetic condition. For example, 49% of the individuals with Williams syndrome interviewed in the study by Farwig et al
A 20-year-old man with Williams syndrome stated “Personally, I like having Williams syndrome because it is different from everybody else. I’d feel perfect about it.”
Two participants related their own lived experience of disability to their potential roles as parents of children with disabilities:Interviewee: “If you were going to have a baby and they said this baby’s going to have Down syndrome, what would you do?”Martha (35-year-old woman with Down syndrome) stated “I know what to do, you know, it’s quite easy [laughs] everything, you know, the baby, it’s a human being, feed it, look after, give it lots of love”.
In another study, Yvette (a 20-year-old woman with presumed autosomal dominant intellectual disability associated with microcephaly) said “No one could be a better mother to her than I am, because I've been there.”
Opinions varied on whether people with a prenatal test confirming a genetic cause of intellectual disability should consider fetal termination: a workshop participant (no demographic details available) said “Disabled babies are OK.”
Another workshop participant (no demographic details available) said “The foetus should be aborted if a test shows it has a learning difficulty because I don’t think it should be born into a cruel world.”
Several individuals were able to articulate a separation of their personal beliefs about termination from an understanding of what another individual might choose. Becky and Jen, 2 women aged between 25 and 30 years with Down syndrome, stated that babies with Down syndrome would be wanted in their families, yet they used language that suggested they could nevertheless understand another mother’s wish to terminate the pregnancy. This was interpreted by Barter et al
as highlighting “the extremely powerful discourse of private tragedy and public catastrophe which serves the function of rationalizing the choice to terminate.” This ability of individuals with intellectual disability to reflect on others’ right to personal choices that may differ from their own beliefs and choices was reported in other studies.John (a 20-year-old man with Down syndrome) said “It all depends how they feel. Let’s say me, for example. If I were to discuss abortion, I would. But you’ve got to contact someone who wants a baby…I would discuss it with my ‘wife’… and see how she feels.”
A workshop participant (no demographic details available) stated “There should be tests for women who are pregnant, to see how the baby is. If it has Down’s syndrome, the parents need someone to talk to. They need to find out what people with Down’s syndrome can do. You should think of the baby as a baby first, not just that it has Down’s syndrome....”
Opinions about whether genetic testing should be offered to individuals with intellectual disability postnatally for diagnostic reasons were not directly canvassed in most studies, although alluded to in the study on the experiences of individuals with 22q11 deletion by Costain et al
What are the experiences of people with intellectual disability of genetic testing and counselling?
Information on the experiences of people with intellectual disability who have undergone genetic counselling and testing was very limited. In the POMONA-ESP study, only 14.5% of participants stated that they had received a genetic test,
although the percentage of participants who received genetic counselling was not reported. A lack of genetic counselling was implied in the studies by Barter et al,
did not identify themselves as having Down syndrome. Why this was the case was not further explored, but 1 possible explanation could be a lack of genetic counselling. Ward et al
included information sessions provided by disability experts (nongenetic professionals), which covered topics including genes and “things that might run in people’s families.”
An apparent lack of knowledge of the possibility of a genetic cause of intellectual disability was evident, despite at least 3 individuals having a confirmed genetic diagnosis of Down syndrome or Fragile X syndrome. For example, Ward et al
reported that as part of their workshop, “people wondered whether learning difficulties was ‘on a gene or not’ and discovered that sometimes it was – and this sometimes meant you could find out in advance whether your baby was going to have a learning difficulty before it was born.” Only 1 of the 5 adults with Down syndrome interviewed by Alderson
discussed their own genetic counselling experience. This individual remembered that the content of the consultation focused mainly on his responsibility for potentially parenting a child. However, how that conversation had made him feel was not documented.
were directly asked about their perceived utility of their genetic counselling, which was appropriate given that the author herself had provided the genetic counselling.
More information on the experiences of people with intellectual disability with formal genetic counselling in a clinical setting was provided by the studies by Farwig et al
noted that all 43 participants with Williams syndrome had had a genetic counselling session and that 81% expressed that they had learned something new as a result. Individuals were able to recall what they had learnt:A 43-year-old woman with Williams syndrome said “I learned about the chromosomes, which, which I could never understand what the chromosomes were until she showed me the picture of the missing gene. Now I’ve realized what, what this is all about now.”
Several individuals were also able to reflect on how this newly gained knowledge had made them feel, including, eg, a reduction in guilt or blame.A 32-year-old man with Williams syndrome stated “Yeah, I learned that the parents don’t cause me to have Williams syndrome. It wasn’t my mom or my dad, … it was the genes itself. Because of the chromosome…. That’s amazing. I never knew that; blew my mind … when I heard that. Wow. It wasn’t my parents’ fault. It was nobody’s fault. It just happens.”
All but 1 individual (98%) said that they would recommend genetic counselling to other people with Williams syndrome.
focused on the opinions of adults with 22q11.2 about the value of a genetic diagnosis. Both caregivers and individuals with 22q11.2 deletion reported multiple positive aspects of receiving a genetic diagnosis. For example, 1 adult described the benefit of his diagnosis, which allowed him access to specialized clinics and expert consultations:“The only improvement that I received was from specialised Drs that did help me”.
Whereas others commented on the value of having an explanation for their health or learning difficulties:“When I found out I had 22q it put me at a place where at least I knew why I had all this [sic] learning difficulties with school, work, etc.”
How inclusive and accessible was the research conducted with people with intellectual disability?
The level of detail given on the attention paid to inclusive research design principles in the study design and conduct varied between studies (summarized in Table 2). Although no studies included a person with intellectual disability as a primary researcher, Barter et al
did consult someone with Down syndrome on study design. Although consent to participate was obtained in all studies, only 2 elaborated on how informed the consent process was. Both Barter et al
went to significant lengths to ensure consent was genuinely informed: both groups included a prestudy information session for prospective participants and their supporters to allow participants to become familiar with the researchers and the topics that would be discussed and gave opportunities for participants to reach their own decisions about participating in the study or not.
that were all conducted in the United Kingdom described the measures they took to maximize the comfort of the study participants and improve accessibility. Ward et al
chose small group workshops with attention paid “to making the workshop days as comfortable as possible, with a warm and welcoming venue, transport, and the kind of meals and breaks that people had said beforehand that they would like.” Barter et al
allowed participants to choose where they would like the interviews to be conducted, with 4 opting for a private space in their home and 2 opting for their place of work. Alderson
also stated that interviews were conducted in individuals’ homes or colleges and that she used “open questions to encourage free talking, and to share control over topics, pace and style” and to engender “mutual trust and respect.” Recognizing the potential distress that could be caused by topics related to prenatal genetic testing, Ward et al
provided additional funding for professional mental health support if participants required.
Only 2 of the studies reported efforts to disseminate their findings in a form accessible to participants and/or people with intellectual disability more generally. Alderson
phoned the interviewees a week after their interview to check that they “felt all right” and ask if they had anything to add. She sent transcripts and a short report back to participants, although it is unclear if the latter was in an Easy Read format. Ward et al
took a very proactive approach to knowledge exchange following their study. They invited participants to nominate themselves to present the key findings from the workshops at a national conference focused on genetic testing and disabilities. Four participants chose to present, and their presentations were described by the authors as “the high spot of a day which featured contributions by parents, leading commentators in the field of genetics, international experts on bio-ethics and learning difficulties, key commentators on ethical issues, and a powerful account by a disabled professional.” They commented that the presentation demonstrated persuasively that people with learning difficulties were capable of understanding and appreciating the issues involved in choices for prenatal genetic testing.
Discussion
The most striking finding of this systematic literature review was the paucity of research on the opinions and experiences of people with intellectual disability about genetic counselling and testing. This lack of research is in stark contrast with the scale of genetic testing conducted on people with intellectual disability and that of prenatal screening or testing for genetic causes of intellectual disability.
Moreover, it was difficult to assess whether the included studies followed the current best practice for inclusive research (Table 2). Consequentially, the usefulness of the findings may potentially be reduced if the use of noninclusive research methods limited the ability of participants to express their views openly.
However, despite being limited in number, the included studies present compelling support for both the ability and the desire of people with intellectual disability to discuss genetic concepts. Many participants expressed satisfaction at being asked their opinions on genetic testing.
Those studies that included the provision of genetic information, genetic counselling sessions, or education workshops were noted to be particularly valuable. For example, participants recommended these services to others with an intellectual disability.
When directly questioned, people who had visited a genetic professional could recall information discussed, including the cause, inheritance, and chance of recurrence of their condition in offspring.
study provide preliminary evidence that people with intellectual disability have found personal utility in having a genetic diagnosis. The positive effects reported ranged from access to improved medical care; anticipatory surveillance; educational support, which leads to improved sense of identity; better understanding of their own condition; connection with others; and removal of guilt.
However, the potential impact genetic counselling may have on individuals with intellectual disability in terms of promoting informed choice regarding genetic tests; providing information and psychosocial support; and facilitating patient empowerment has not been systematically explored with a representative cohort of individuals with intellectual disability as they have been in the general population receiving genetic counselling.
It would be an important future direction to explore if genetic counselling affects thoughts and opinions of people with intellectual disabilities about their own conditions.
The studies showed that people with intellectual disability could express a wide range of opinions on prenatal genetic testing. Similarly, they had a wide variety of emotional reactions to questions about whether they would like to have children or to be offered a test during pregnancy to see if their baby has a genetic condition and how they might respond to the result.
Many people were able to distinguish their own opinions from an appreciation of the right of others to choose on the basis of their personal situations and beliefs. Several made it clear that they were considering the thoughts and opinions of others, including potential future children, which contrasts with earlier suggestions that people with intellectual disabilities have perspectives on genetic testing that are largely egocentric.
‘This is the child we were given’: A qualitative study of Danish parents’ experiences of a prenatal Down syndrome diagnosis and their decision to continue the pregnancy.
The legal frameworks for prenatal genetic testing and termination vary from state to state and country to country, as does the uptake of prenatal screening and subsequent termination of pregnancy. For example, termination rates for all aneuploidies vary from 40% to 95% according to location.
Danish Fetal Medicine Study Group. Parental decisions about prenatal screening and diagnosis among infants with trisomy 21 in a national cohort with high uptake of combined first-trimester screening.
Many of the general public have religious, spiritual, or ethical objections to the prenatal termination of fetuses with a genetic cause for intellectual disability. They may have concerns about discrimination against the unborn fetus, that selective termination sends out a hostile message to others with disability or that it represents a “fundamentally misguided notion of parenthood as an opportunity to pick and choose the perfect child.”
Parents who have chosen to continue a pregnancy after a prenatal diagnosis of Down syndrome have emphasized that they have “chosen the child, not the syndrome …that the child was not something that could be returned or exchanged because it did not fit their dream future.”
‘This is the child we were given’: A qualitative study of Danish parents’ experiences of a prenatal Down syndrome diagnosis and their decision to continue the pregnancy.
In contrast, other members of the general population see advantages to the availability of prenatal genetic testing and termination for intellectual disability, with termination as an act to “prevent the suffering of either the disabled fetus itself or the family as a whole.”
It was also clear that some study participants found prenatal testing and the possibility of termination too uncomfortable and personal to discuss, highlighting how important it is for health care professionals to approach genetic counselling for people with intellectual disability with sensitivity and responsiveness to the preferences of each individual in line with current best practice.
To explore how best to conduct genetic counselling, research needs to be done using inclusive methods to ensure that the opinions and preferences of people with intellectual disability are incorporated into the recommendations for best practice. A search for publicly available training resources giving best practice guidelines for conducting genetic counselling with people with intellectual disability revealed only 1 teaching case study, included as part of a US National Society of Genetic Counselors online genetic counselling toolkit https://www.geneticcounselingtoolkit.com/genetic_counseling_cases.htm (case 1). However, it was not clear whether the opinions or preferences of people with intellectual disability had been sought in the preparation of the toolkit.
No publicly available genetic counselling aids or assent/consent forms for people with intellectual disability were mentioned in any of the 7 studies. Ward et al
used flip charts developed in-house and a combination of pictures and group discussions to discuss topics such as genes, genetic predispositions to intellectual disability, and prenatal testing. Farwig et al
included in their supplementary material copies of the homemade visual aids that they used, eg, the information that Williams syndrome occurs because “a tiny piece of chromosome 7 is missing.” Our own search of the published and gray literature found no freely available genetic educational resources or genetic assent or consent forms specifically designed for people with intellectual disability, other than our own recently codeveloped Easy Read resource for people with intellectual disability, which was designed to assist in preparation for attending a genetics clinic.
GenomicsEngland at one time had an online Easy Read participant information sheet (https://www.genomicsengland.co.uk/information-for-participants/participant-forms/), but this was withdrawn at the end of the recruitment period for GenomicsEngland’s genetic studies (personal communication). Thus, an important priority for future research will be to codesign and evaluate accessible genetic counselling and testing resources, such as Easy Read versions, in collaboration people with intellectual disability.
Conclusion
This review summarizes the current body of knowledge on the opinions and experiences of people with intellectual disability in genetic testing. In doing so, it has highlighted just how limited our knowledge in this area is, despite the increasing amount of genetic testing performed on people with intellectual disability.
This systematic literature review provides the foundation on which to build future inclusive research with people with intellectual disability about their experiences with genomic health services and on which to codesign appropriate genomic resources to support and empower people with intellectual disability in their genomic health care. The current paucity of inclusive research on the opinions and experiences of people with intellectual disability in genetic counselling and testing represents a profound failure of health care accessibility and equity that future research must urgently address.
Data Availability
Data relevant to this systematic review are available upon request.
Conflict of Interest
The authors declare no commercial associations that might pose, create, or create the appearance of a conflict of interest with the information presented in this manuscript.
Acknowledgments
This work was supported by the Disability Innovation Institute at UNSW Sydney, Sydney, Australia.
Meta-analysis and multidisciplinary consensus statement: exome sequencing is a first-tier clinical diagnostic test for individuals with neurodevelopmental disorders.
Consensus statement: chromosomal microarray is a first-tier clinical diagnostic test for individuals with developmental disabilities or congenital anomalies.
‘This is the child we were given’: A qualitative study of Danish parents’ experiences of a prenatal Down syndrome diagnosis and their decision to continue the pregnancy.
Danish Fetal Medicine Study Group. Parental decisions about prenatal screening and diagnosis among infants with trisomy 21 in a national cohort with high uptake of combined first-trimester screening.
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