FGF8 and Kallmann syndrome: In humans, mutations in FGF8 and FGFR1 are known to cause congenital hypogonadotropic hypogonadism (CHH) without or with anosmia, i.e. CHH+anosmia (Young et al., 2019), septo-optic dysplasia or combined pituitary hormone deficiency (Raivio et al., 2012), Hartsfield syndrome (Palumbo et al., 2019), holoprosencephaly and split hand/foot malformation (Villanueva et al., 2015).