ISSN: 1300-0292
İndekslendiği Dizinler: SCIENCE CITATION INDEX EXPANDED
CINAHL, Index Copernicus,
Chemical Abstracts (CA),
Excerpta Medica / EMBASE
Dil: Türkçe, İngilizce
İçerik: Orijinal Araştırma, Derleme, Editöre Mektup, Olgu Sunumu, Tıp Eğitimi, Tıbbi Kitap İncelemeleri
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Genetics Of Congenital Adrenal Hyperplasia
Dr.Güler ÖZER,a Dr.U. Güney ERGÜNb
aPediyatrik Endokrinoloji ve Metabolizma BD, b Aile Hekimliği AD, Çukurova Üniversitesi Tıp Fakültesi ADANA
Congenital adrenal hyperplasia (CAH) is a common, autosomal recessively inherited, metabolic and endocrinologic disorder caused by a deficiency in one of the enzymes necessary for the synthesis of cortisol in the adrenal cortex.
21 hydroxylase deficiency: More than 90% of all cases of CAH is caused by 21 hydroxylase deficiency. The gene which codes 21 hydroxylase has two separate forms, a functional gene (CYP21) and a nonfunctional pseudogene (CYP21P). Due to the un-resiprocal coupling, unequal cross over and inter-genic recombination of the DNA strings of the both genes, the mutation which naturally appears on the pseudogene is transferred onto the active gene. The 90% of the mutations forms in that way, while the other 10% appears de novo. Deletions (8-36%), duplications (2-9%), point mutations (36-38%) and CYP21/CYP21P gene conversions (3-15%) have been seen with different percentages in case studies. For accurate and reliable molecular diagnosis various analysis methods have been developed. Substrate-function interference is studied with in vitro expression studies.
11 hydroxylase deficiency: The gene CYP11 B1 of this enzyme is localized to chromosome 8q21-q22. Its expression is weak in the zona fasiculata and it only arranges 11 hydroxylation. Structure-function inferences are investigated with expression studies. In Japan and France, the CYP11B1/CYP11B2 hybrid gene has been found in CAH cases that have occured as a consequence of 11 hydroxylase deficiency.
3 beta hydroxysteroid dehydrogenase (HSDs) deficiency: HSD3 B1 and HSD3 B2 genes, which code the two izoenzymes, are localized to chromosome 1p13,1. Expression of the HSD3 B2 gene is active in the adrenals and gonads. The mutations have been correlated with the severe (salt-wasting type) and simple types of disease and in vitro expression studies have been performed.
17 hydroxylase deficiency: CYP17 gene, which codes the 17 hydroxylase, is localized to chromosome 10q24-q25. Substrate-function interference have been studied in in vitro expression studies and more than 20 genetic deficiencies have been defined.
Congenital lipoid adrenal hyperplasia (CLAH): In vitro expression studies have been performed to define the compound heterozygous mutations on the CYP11A gene, which is localized to chromosome 15q23-q24. Investigations are still being carried on with respect to StAR gene, which is localized to chromosome 8p11,2.Keywords: Congenital adrenal hyperplasia, genetical approachTurkiye Klinikleri J Med Sci 2004, 24:68-77
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