Clinical and radiologic evaluation of a Turkish family with hypochondroplasia and a rare FGFR3 variant

Abstract Objectives Hypochondroplasia (HCH) is characterized by disproportionate short stature and regarded as a milder form of achondroplasia (ACH), which is another skeletal dysplasia, both caused by variants in fibroblast growth factor receptor 3 (FGFR3) gene. HCH diagnosis is based on the clinical features and skeletal survey findings. The most common FGFR3 variant in HCH affects the codon 540, leading to substitution of asparagine with lysine in about 70% of patients. Case presentation Herein, we described the clinical and radiographical manifestations of HCH in affected members of a Turkish family with very rare Asn540Thr (c.1619A>C) variant within hot spot of the gene for this condition. Conclusions This is a very rarely reported variant in the literature and this report is the first case with this variant in Turkish population. The report also presents the phenotypic variability within a family with the same variant, which is inherent to HCH.