Over the last two decades, dominant gain-of-function mutations of the specific site in fibroblast growth factor receptor 3 (FGFR3) have been shown implicated in human skeletal dysplasias, including achondroplasia (ACH), hypochondroplasia (HCH), thanatophoric dysplasia (TD) and severe achondroplasia, with developmental delay and acanthosis nigricans (SADDAN) [4, 10]. The gene discussed is FGFR3; the disease is Severe achondroplasia - developmental delay - acanthosis nigricans.