Anticipatory banking of samples enables diagnosis of adenylosuccinase deficiency following molecular autopsy in an infant with vacuolating leukoencephalopathy

S. Sitaram, H.C. Banka*, G. Vassallo, J. Pavaine, A. Fairclough, R. Wright, L. Fairbanks, J. Bierau, L. Bowden, B. Schwahn, A. Horman, S. Banka*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Adenylosuccinase deficiency is a rare inborn error of metabolism. We present a newborn who died at 52 days of age with clinical features suggestive of severe epileptic encephalopathy and leukodystrophy of unknown cause. Post-mortem examination showed an unusual vacuolar appearance of the brain. A molecular autopsy performed via singleton clinical exome analysis revealed a known pathogenic and a variant of uncertain significance in ADSL that encodes adenylosuccinase. Tests on previously stored plasma samples showed elevated succinyladenosine and succinylaminoimidazole carboxamide riboside levels. Adenylosuccinase activity in stored fibroblasts was only similar to 5% of control confirming the diagnosis of adenylosuccinase deficiency in the child. The parents opted for a chorionic villus biopsy in a subsequent pregnancy and had a child unaffected by adenylosuccinase deficiency. This report adds vacuolating leukodystrophy as a novel feature of adenylosuccinase deficiency and shows the power of biochemical investigations directed by genomic studies to achieve accurate diagnosis. Importantly, this case demonstrates the importance of anticipatory banking of biological samples for reverse biochemical phenotyping in individuals with undiagnosed disorders who may not survive.
Original languageEnglish
Pages (from-to)234-237
Number of pages4
JournalAmerican Journal of Medical Genetics Part A
Issue number1
Early online date1 Oct 2022
Publication statusPublished - Jan 2023


  • adenylosuccinate lyase
  • molecular autopsy
  • reverse phenotyping

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