3M syndrome is a rare autosomal recessive disorder caused by biallelic pathogenic variants in the cullin 7 (CUL7), obscurin-like 1 (OBSL1), and coiled-coil domain-containing protein 8 (CCDC8) genes and is characterized by pre- and postnatal growth retardation, short stature, dysmorphic facial features, and skeletal anomalies, with normal intelligence. The gene discussed is CUL7; the disease is 3M syndrome.