Novel WAC gene variant identified in the first documented case of DeSanto-Shinawi Syndrome in India.

Background: DeSanto-Shinawi Syndrome (DESSH) is a rare neurodevelopmental disorder characterized by intellectual disability, behavioral abnormalities, and distinctive dysmorphic features, linked to likely pathogenic/pathogenic variants in the WAC gene. We report the first documented case of DESSH in India, identified in a 3-year-old male presenting with global developmental delay and coarse facies.

Results: Exome sequencing revealed a novel heterozygous nonsense likely pathogenic variant (c.1661 C>A(p.Ser554*)) in the WAC gene, expanding the genotypic spectrum associated with this condition. We employed computational methodologies to understand the effects of this novel variant on protein structure and function. In-silico prediction score suggested protein truncation due to the c.1661 C>A (p.Ser554*) variation in the WAC gene, expected to result in a loss of normal protein function.

Conclusion: The findings advocate for increased awareness and genetic testing in atypical cases to facilitate accurate diagnosis and management. This case underscores the importance of considering DESSH in the differential diagnosis of similar neurodevelopmental disorders and enhances our understanding of the genetic diversity within the WAC gene.