Novel OBSL1 Variant in a Chinese Patient with 3M Syndrome: The c.458dupG Mutation May Be a Potential Hotspot Mutation in the Chinese Population.

3M syndrome is an autosomal recessive disorder characterized by short stature and skeletal developmental abnormalities. A Chinese girl with 3M syndrome and a novel OBSL1 (obscurin-like 1 gene) variant is presented. The patient is a 2-year-old girl who presented with short stature and had intrauterine growth retardation and low birth weight. Gene analysis revealed compound heterozygote mutations in the OBSL1 gene: c.458dupG (p.L154Pfs*100) and c.427dupG (p.A143Gfs*111). The c.427dupG mutation is novel. The c.458dupG mutation has been documented in five cases, occurring only in Chinese individuals, suggesting ethnic specificity. In cases of children with short stature presenting with intrauterine growth retardation, low birth weight, and skeletal developmental abnormalities, 3M syndrome should be considered. The c.458dupG mutation may be a hotspot mutation in the Chinese population.