3‐M syndrome is classified into types I, II, and III, which have been identified to be associated with the exclusive variants in cullin 7 (CUL7; MIM *609577), obscurin‐like 1 (OBSL1; MIM *610991), and coiled‐coil domain‐containing protein 8 (CCDC8; MIM *614145) genes, respectively. The gene discussed is OBSL1; the disease is 3-M syndrome.