A missense mutation of C1659 in the fibroblast growth factor receptor 3 gene in Russian patients with hypochondroplasia

To carry out the genetic screening for the common mutation in the first tyr osine kinase domain (TK1) of the fibroblast growth factor receptor 3 gene ( FGFR3) in a Russian population, a cohort of 16 patients with hypochondropla sia diagnosed previously were studied, among them twelve familial cases and four sporadic cases. The heterozygous N540K FCFR3 mutation was detected in 9 cases (56.3%) due to that C1659A substitution in 6 patients and C1659G s ubstitution in 3 patients, respectively. The ratios of familial and sporadi c cases among patients which carried FGFR3 mutation were similar. Seven (43 .7%) patients, negative cases of N540K mutation, were all familial cases. O ur results support evidence of similar frequency of common type N540K mutat ion of FGFR3 in Russian hypochondroplasia and of the genetic heterogeneity of hypochondroplasia, suggesting the need for further search for responsibl e molecular abnormalities for phenotypically similar hypochondroplasia pati ents negative for TK1 domain mutation in FCFR3, reported in hypochondroplas ia.