Homozygous R383H variant in IDUA gene causing pericentric retinitis pigmentosa in attenuated mucopolysaccharidosis type I.
Goura Chattannavar, Pravalika Sadhu, Subhadra Jalali et al.
✦ AI-curated · Sources linked
Case in brief
A patient presented with congenital dyschromatopsia, adult-onset pericentric retinitis pigmentosa, and cardiac valve disease. Genetic testing revealed a homozygous pathogenic variant in the IDUA gene (R383H), indicating attenuated Mucopolysaccharidosis type I. The patient exhibited significantly reduced iduronidase enzyme activity and elevated urine glycosaminoglycans, leading to a comprehensive evaluation and management plan.
Diagnostic / clinical pearl
This case underscores the importance of enzyme activity assessment in interpreting genetic findings, particularly when multiple variants are present that may contribute to similar clinical manifestations.
Why it matters
The findings emphasize the necessity for extensive genetic testing in cases where initial panel results are inconclusive, ensuring accurate diagnosis and management of complex phenotypes.