A Novel Variant in Heparan Sulfate Proteoglycan 2 Gene Causing Schwartz–Jampel Syndrome – A Case Report from India

Abstract Schwartz–Jampel Syndrome (SJS) type 1 (OMIM #255800) is a rare autosomal recessive genetic disorder characterized by myotonia, chondrodysplasia, and a distinctive mask-like facial appearance. This slowly progressive condition typically manifests in early infancy and is caused by mutations in the heparan sulfate proteoglycan 2 (HSPG2) gene, which encodes perlecan, a crucial component of the extracellular matrix. We report a case of SJS presenting with classic dysmorphic features and characteristic musculoskeletal involvement. This case is noteworthy due to its rarity and the identification of a previously unreported novel mutation in the HSPG2 gene. Our findings emphasize the significance of clinical recognition and molecular diagnosis in rare genetic disorders and contribute to the growing understanding of the genetic underpinnings of this condition.