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eP036: Not your typical newborn screen for X-ALD: Outcomes from Washington State

      Background

      X-linked adrenoleukodystrophy (X-ALD) is an X-linked genetic condition caused by pathogenic variants in the ABCD1 gene that primarily affects the adrenal glands and nervous system. The known clinical manifestations include isolated adrenal insufficiency, childhood cerebral disease, adult-onset adrenomyeloneuropathy with or without cerebral involvement in hemizygotes, and myelopathy in heterozygotes. X-ALD was added to the recommended uniform screening panel in February of 2016, and Washington State began screening for X-ALD in March of 2018. Washington State’s newborn screening program typically measures metabolites on at least two dried blood spot specimens, collected at approximately 24 hours of life and at 1-2 weeks of life.

      Case presentation

      Here we present unusual cases that screened positive for X-ALD on Washington State newborn screening and discuss possible implications including potential causes for false positive screens, unexpected clinical progression, challenges with further workup of ambiguous biochemical and molecular results, and unexpected results from family cascade testing.

      Conclusion

      We have encountered multiple unexpected clinical scenarios in individuals who screened positive for X-ALD, as expected when introducing a new condition to newborn screening. These cases outline important implications to consider in the newborn screening follow-up and clinical care for these individuals.