73-year-old patient becomes the oldest documented case of Smith-Lemli-Opitz syndrome

A 73-year-old woman with amnesia and movement disorders, under neurology care for three years, was referred for genetic analysis after presenting with partial syndactyly, a wide forehead, and a triangular face. Despite no significant dysmorphic findings, her symptoms prompted whole-exome sequencing (WES) to identify the genetic cause.

The WES analysis uncovered a novel homozygous missense mutation, c.1295A>G (p.Tyr432Cys), in the DHCR7 gene. This particular variant has been previously reported in 9 patients, but this case is notable as it is the first documented instance of biallelic c.1295A>G (p.Tyr432Cys) in the literature. The patient also exhibited mild intellectual impairment, recurrent hip dislocation, and subtle dysmorphic features.

This case is significant as it represents the oldest known patient with SLOS, highlighting the potential for milder manifestations of the syndrome.

Reference
Yılmaz M, Bebek O, Turkyilmaz A. Smith-Lemli-Opitz Syndrome with Biallelic c.1295A>G (p.Tyr432Cys) Variant in the DHCR7 Gene in a 73-Year-Old Woman: Report of the Oldest Patient. Mol Syndromol. 2024;15(4):317-323. doi: 10.1159/000536343. Epub 2024 Feb 23. PMID: 39119449; PMCID: PMC11305663.