Reports on Medical Genetics Findings from Icahn School of Medicine at Mount Sinai Provide New Insights (Maternal Uniparental Isodisomy of Chromosome 2 Leading to Homozygous Variants in SPR and ZNF142 : A Case Report and Review of...).

A recent study conducted by researchers at the Icahn School of Medicine at Mount Sinai in New York City has identified a 4-year-old girl with neurodevelopmental abnormalities who has maternal uniparental isodisomy of chromosome 2. This condition has led to homozygosity for a likely pathogenic variant in SPR and a variant of uncertain significance in ZNF142. The study found that biallelic pathogenic variants in SPR are associated with sepiapterin reductase deficiency (SRD), a dopa-responsive dystonia, while pathogenic variants in ZNF142 are associated with an autosomal recessive neurodevelopmental disorder characterized by impaired speech and hyperkinetic movements. The patient showed significant improvement in motor skills after treatment with levodopa. The study also reviewed 67 published reports of uniparental disomy of chromosome 2 (UPD2) and explored the mechanisms giving rise to UPD2. [Extracted from the article]