Adrenal Hyperplasia Type 5 or Congenital Adrenal Hyperplasia due to 17 Alpha-hydroxylase Deficiency


Adrenal hyperplasia type 5 (AH5; Congenital Adrenal Hyperplasia due to 17 Alpha hydroxylase Deficiency) is a form of congenital adrenal hyperplasia. It is caused by a defect in the CYP17A1 gene which codes for Steroid 17-alpha-hydroxylase/17,20 lyase. These 2 enzymes convert pregnenolone and progesterone to their 17-hydroxy forms in steroidogenesis and mediate three key transformations in cortisol and sex steroid synthesis. A defect in 17-alpha-hydroxylase results in decreased synthesis of both cortisol and sex steroids; increase in mineralocorticoids. Common symptoms include mild hypocortisolism, ambiguous genitalia in genetic males or failure of the ovaries to function at puberty in genetic females, and hypertension. Hypertension and mineralocorticoid excess is treated with glucocorticoid replacement. Genetically female patients need female hormone replacement to induce puberty and regulate menses. Surgery may be needed for males with ambiguous genitalia. Testosterone must be replaced for genetically males (XY) to induce puberty and continued throughout adult life.

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References

  1. Wikipedia: Congenital adrenal hyperplasia due to 17 alpha-hydroxylase deficiency
  2. Uniprot: P05093
  3. eMedicine: Article 920532-overview
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  4. Biglieri EG: 17 alpha-Hydroxylase deficiency: 1963-1966. J Clin Endocrinol Metab. 1997 Jan;82(1):48-50. Pubmed
  5. Biglieri EG, Herron MA, Brust N: 17-hydroxylation deficiency in man. J Clin Invest. 1966 Dec;45(12):1946-54. Pubmed
  6. Geller DH, Auchus RJ, Mendonca BB, Miller WL: The genetic and functional basis of isolated 17,20-lyase deficiency. Nat Genet. 1997 Oct;17(2):201-5. Pubmed
  7. Heremans GF, Moolenaar AJ, van Gelderen HH: Female phenotype in a male child due to 17-alpha-hydroxylase deficiency. Arch Dis Child. 1976 Sep;51(9):721-3. Pubmed