3M syndrome is an autosomal recessive disease characterized by severe pre-natal and post-natal growth retardation, dysmorphic facial features, and skeletal abnormalities. We present a patient with 3M syndrome caused by the compound heterozygous mutations p.Trp68* and p.Gly1452Asp in CUL7, the latter of which is novel, who exhibited a good body height response to growth hormone treatment. These results expand our knowledge of phenotype-genotype correlations in 3M syndrome, including correlations relevant to growth hormone response.