FGFR1 and hypogonadotropic hypogonadism: Kallmann syndrome, characterized by hypogonadotropic hypogonadism with anosmia, is caused by several genetic abnormalities, including fibroblast growth factor receptor 1 (FGFR1) and KAL1 [14,15]. Mutations in the androgen receptor (AR) gene, located on the X chromosome, have been identified as a primary cause of moderate to severe androgen insensitivity syndrome (AIS), resulting in diminished androgen responsiveness and subsequent disruptions in male sexual differentiation [16].