A case of LSS-associated congenital nuclear cataract with hypotrichosis and literature review.

Abstract

Congenital cataract is the most common cause of lifelong visual loss in children worldwide, which has significant genotypic and phenotypic heterogeneity. The LSS gene encodes lanosterol synthase (LSS), which acts on the cholesterol biosynthesis pathway by converting (S)-2,3-oxidosqualene to lanosterol. The biallelic pathogenic variants in the LSS gene were found in congenital cataract, Alopecia-intellectual disability syndrome, hypotrichosis simplex, and mutilating palmoplantar keratoderma. In this study, we reported the first congenital nuclear cataract combined with hypotrichosis in a 12-year-old boy with biallelic LSS variants (c.1025T>G; p.I342S and c.1531_1532insT; p.L511Ffs*17) by exome sequencing. Reviewing all reported patients with LSS variants indicated that p.W629 might be a hotspot for hypospadias and p.I342S was associated with congenital cataract. Patients with one or two truncation variants tend to have multisystem symptoms compared with those with two missense variants. These findings deepen the understanding of LSS variants and contribute to the genetic counseling of affected families.