The genetic and molecular basis of idiopathic hypogonadotropic hypogonadism To date at least 25 different genes have been implicated in causing<unk>  or other forms of hypogonadotropic hypogonadism through a disruption in the production or activity of GnRH (37). These genes involved cover all forms of inheritance and no one gene defect has been shown to be common to all cases which makes genetic testing and inheritance prediction difficult. The number of genes known to cause cases of<unk> /CHH is still increasing. In addition it is thought that some cases of<unk> /CHH are caused by two separate gene defects occurring at the same time. Individual gene defects can be associated with specific symptoms which can help in identifying which genes to test for. Between 35-45% of cases of<unk> /CHH have an unknown genetic cause. The ANOS1 gene defect (previously known as KAL-1) was the first one discovered and the one most commonly tested for. It causes the x-linked form of<unk>  and is associated with the additional symptoms of anosmia, bimanual synkinesis and renal agenesis. This defect is thought to be responsible for between 5 and 10% of all<unk> /CHH cases.
Kallmann syndrome
Klinefelter syndrome
Waldmann disease
Turner syndrome
Angelman syndrome
Hanhart syndrome
Parsonage–Turner syndrome
Gerstmann syndrome