Congenital defects

Reduced number of germ cells

Increased follicular atresia

X chromosome alterations

Enzymatic alterations

17a -hydroxylase deficiency

Galactosemia

Gonadotropin secretion alterations

Secretion of biological inactive forms

α or ß subunit defects

Gonadotropin receptor alterations

Resistant ovary syndrome (Savage syndrome)

Autoimmune disorders

Isolated

Associated with other endocrine disorders

Iatrogenic causes

Radiotherapy

Chemotherapy

Ovariectomy

Infectious causes

Viral agents

Idiopathic