Possible explanations include a variant at another locus encoding a CHD7-interacting protein (whether physically interacting or involved in a genetic/synergistic interaction) required for development of the endolymphatic sac and duct, as previously described in Kallmann syndrome and hypogonadotropic hypogonadism (Marcos et al. 2014). This evidence concerns the gene CHD7 and hypogonadotropic hypogonadism.