TUBB3 and hypogonadotropic hypogonadism: There are also numerous syndromic conditions associated with hypogonadotropic hypogonadism, including Gordon Holmes syndrome, CHARGE syndrome, and the soxopathies (SOX10 and SOX11 deficiency).[156, 157, 158, 159] Defects in many of these genes are also associated with phenotypes of neurodisability, such as in hypomyelinating leukodystrophy‐8 with hypogonadotropic hypogonadism (4H syndrome) due to mutations in POLR3A/B, or secondary to PNPLA6 deficiency, or to TUBB3 deficiency.[160, 161, 162]