Hypomorphic IDUA genotypes are associated with retinitis pigmentosa in individuals without syndromic mucopolysaccharidosis type I.

Hypomorphic IDUA genotypes are linked to late-onset retinitis pigmentosa without systemic MPS I features in individuals aged 46-73 years.

• Why it matters: Understanding the genetic basis of isolated retinal disease can improve diagnosis and reveal mechanisms underlying phenotypic variability in metabolic disorders.
• What they did: The study analyzed 14 individuals from 12 families with bi-allelic IDUA variants, assessing enzyme activity, genetic variants, and functional effects through cell-based assays and transcript analysis.
• The result: Findings show residual enzyme activity in all assessed individuals, with most carrying hypomorphic alleles, expanding the phenotypic spectrum of IDUA-related disease to include retinal-predominant forms and emphasizing the importance of integrated genomic and functional analyses.