LSS and alopecia - intellectual disability syndrome: Here, we identified a novel mutation in LSS. LSS is a key enzyme in the cholesterol biosynthesis pathway that catalyzes the first step of the biosynthesis of cholesterol, steroid hormones, and vitamin D. Recently, mutations in LSS have been reported to be associated with congenital cataracts, hypotrichosis simplex, and alopecia-mental retardation syndrome (Zhao et al., 2015; Chen and Liu, 2017; Romano et al., 2018; Besnard et al., 2019).