Pituitary gene mutations and the growth hormone pathway.

Hereditary forms of pituitary insufficiency not associated with anatomic defects of the central nervous system, hypothalamus, or pituitary are a heterogeneous group of disorders that result from interruptions at different points in the hypothalamic-pituitary-somatomedin-peripheral tissue axis. These different types of pituitary dwarfism can be classified on the level of the defect; mode of inheritance; whether the phenotype is isolated growth hormone deficiency (IGHD) or combined pituitary hormone deficiency (CPHD); whether the hormone is absent, deficient, or abnormal; and, in patients with GH resistance, whether insulin-like growth factor 1 (IGF1) is deficient due to GH receptor or IGF1 defects. Information on each disorder is summarized. More detailed information can be obtained through the electronic database Online Mendelian Inheritance in Man which is available at http://www3.ncbi.nlm.nih.gov/Omim/.