<unk>  is divided into two syndromes:<unk>  with olfactory alterations or anosmia, Kallmann syndrome and<unk>  with normal smell (normosmic<unk> . Kallmann syndrome is responsible for approximately 50% of all cases of the condition. It is associated with mutations in KAL1, FGFR1/FGF8, FGF17, IL17RD, PROKR2, NELF, CHD7(which positively regulates GnRH secretion), HS6ST1, FLRT3, SPRY4, DUSP6, SEMA3A, and WDR11 (gene), genes which are related to defects in neuronal migration. Gene defects associated with<unk>  and normal smell include PROKR2, FGFR1, FGF8, CHD7, DUSP6, and WDR11, as in KS, but in addition also mutations in KISS1R, TACR3, GNRH1/GNRHR, LEP/LEPR, HESX1, FSHB, and LHB. GnRH insensitivity is the second most common cause of<unk> , responsible for up to 20% of cases.A minority of less than 5-10% is due to inactivating mutations in genes which positively regulate GnRH secretion such as CHD7, KISS1R, and TACR3. The causes of about 25% of all<unk>  cases are still unknown.
Isolated hypogonadotropic hypogonadism
Hypergonadotropic hypogonadism
Hypogonadotropic hypogonadism
Late-onset hypogonadism
Hypergonadotropic hypergonadism
Hyperprolactinemic SAHA syndrome
Functional hypothalamic amenorrhea
Dual-role transvestism