title: Diagnosis of homozygosity and heterozygosity in congenital adrenal hyperplasia (CAH) and control of treatment.
abstract: In congenital adrenal hyperplasia the incidence of 21-hydroxylase deficiency is very high (approximately 1:7,000), whereas other enzyme defects such as 11-hydroxylase deficiency, 17-hydroxylase deficiency and 3 beta-hydroxysteroid dehydrogenase deficiency are much less frequent. The various forms of enzyme defects can be diagnosed by determining specific plasma steroids or specific urinary steroid metabolites. A new semi-automatic capillary gas liquid chromatography method has been introduced for the diagnosis of CAH and assessment of therapy. Heterozygous carriers of 21-hydroxylase deficiency can be detected in the general population by measuring 17-hydroxyprogesterone plasma levels after ACTH stimulation; however, results overlap with the general population. In families with a CAH index case, heterozygosity and homozygosity for the 21-hydroxylase deficiency gene can be detected by HLA-typing. 21-hydroxylase deficiency can be diagnosed prenatally by HLA-typing or by determining 17 OH-progesterone levels in the amniotic fluid.
mesh_terms: D000312:Adrenal Hyperplasia, Congenital / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D002849:Chromatography, Gas; D019411:Clinical Laboratory Techniques; D003366:Cosyntropin; D003907:Dexamethasone; D005260:Female; D006580:Genetic Carrier Screening; D006720:Homozygote; D006728:Hormones / Q000652:urine*; D006801:Humans; D008297:Male; D008598:Menstruation; D011278:Pregnanes / Q000627:therapeutic use; D012016:Reference Values; D013250:Steroid Hydroxylases / Q000172:deficiency*; D013256:Steroids / Q000652:urine*
chemical_list: D006728:Hormones; D011278:Pregnanes; D013256:Steroids; D003366:Cosyntropin; D003907:Dexamethasone; D013250:Steroid Hydroxylases