Treating congenital adrenal hyperplasia.

Genettreating congenital adrenal hyperplasia.ic alterations associated with rare endocrine diseases disrupt the body's normal chemical communication system. Faulty genes can affect any part of the hormone pathway by altering the way the body recognises a hormone, or how a hormone acts on a target organ. One example is congenital adrenal hyperplasia. CAH results from an inherited alteration in a gene that blocks an essential enzyme (usually 21-hydroxylase) in the adrenal hormone pathway. Synthesis of cortisol (the "stress" hormone) and aldosterone, which regulates the blood pressure through sodium, potassium and fluid balance, is impaired or absent. The adrenal glands enlarge as they work harder to correct the imbalance, resulting in the overproduction of androgens (male hormones); the more severe the enzyme block, the greater the male hormone production. In 95% of people with CAH, it is due to an alteration in the 21-hydroxylase gene, which is recessively inherited (Perrin et al, 2000). One in 55 people is a carrier for CAH (Baumgartner-Parzer et al, 2005).