title: Genetic disorders of vitamin D biosynthesis.
abstract: The principal hormonal regulator of bone mineralization is vitamin D, which must be activated by a metabolic pathway consisting of a 25-hydroxylase and a 1 alpha-hydroxylase to yield 1,25 dihydroxy vitamin D. The hormonal regulation of vitamin D activation is at the level of the 1 alpha-hydroxylase. This article reviews the biology of vitamin D, and describes the biochemistry of its activation and the molecular biology of the vitamin D-metabolizing enzymes. Recent advances, principally in the authors' laboratories, have resulted in the cloning of the human vitamin D 1 alpha-hydroxylase and the identification of mutations in its gene that cause Vitamin D Dependent Rickets type I.
authors.affiliation: Department of Pediatrics, University of California, San Francisco School of Medicine, USA.
authors.forename: W L
authors.initials: WL
authors.lastname: Miller
authors.forename: A A
authors.initials: AA
authors.lastname: Portale
mesh_terms: D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000172:deficiency / Q000235:genetics; D000818:Animals; D053493:Cholestanetriol 26-Monooxygenase; D003577:Cytochrome P-450 Enzyme System / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D006801:Humans; D009154:Mutation; D013250:Steroid Hydroxylases / Q000172:deficiency / Q000235:genetics; D014807:Vitamin D / Q000096:biosynthesis* / Q000235:genetics*; D065668:Vitamin D3 24-Hydroxylase
chemical_list: D014807:Vitamin D; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; C506831:CYP27A1 protein, human; D053493:Cholestanetriol 26-Monooxygenase; D065668:Vitamin D3 24-Hydroxylase; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase