Two novel homozygous missense mutations in the GDF5 gene cause brachydactyly type C.

Mutations of the GDF5 gene cause a variable phenotype including brachydactyly type C. A review of the literature showed that it is caused either by heterozygous frameshift mutations within the prodomain or heterozygous missense/nonsense mutations within the active domain. Only a single patient with a homozygous mutation (c.517A > G, which predicts p. Met173Val) has been reported in this disorder. In this paper, we report two children with novel homozygous missense mutations in the GDF5 gene associated with brachydactyly type C: one mutation was within the region coding for the prodomain (c.608C > A, which predicts p.Thr203Asn) and the other was within the region coding for the active domain (c.1456 G > A, which predicts p.Val486Met). The genotype-phenotype correlations in the mutational spectrum of the GDF5 gene are discussed.