title: [Polymorphism in the regulatory part of the cholesterol 7 alpha hydroxylase gene in children with high and low levels of cholesterol].
abstract: BACKGROUND
  High plasma cholesterol is one of the risk factors of atherosclerosis. Both environmental (diet, physic activity) and genetic factors have been concerned in the development of hypercholesterolemia. Cholesterol 7 alpha hydroxylase (CYP-7A1) is a key enzyme in the bile acid synthesis and it plays an important role in cholesterol catabolism. The aim of the study was to establish the role of A-204-->C polymorphism in CYP-7A1 gene in plasma lipid determination in children.
  
  
  RESULTS
  Using PCR and restriction analysis (BsaI) we have measured A-204-->C polymorphism in CYP-7A1 gene in two groups of children selected from opposite ends of the cholesterol distribution curve of 2000 children. Eighty-two children in high- (HCG) and eighty-six children in low- (LCG) cholesterolemic groups participated in the study. No significant difference was found in the frequencies of the genotypes or alleles of the A-204-->C polymorphism in the CYP-7A1 gene between HCG and LCG. In HCG, C/C-204 homozygotes have the highest and A/A homozygotes the lowest levels of LDL-cholesterol (4.21 +/- 0.68 mmol/l vers. 3.69 +/- 0.60 mmol/l, p < 0.05). No associations between lipid parameters and genotypes within the LCG group were found.
  
  
  CONCLUSIONS
  The A-204-->C polymorphism in the gene for CYP-7A1 is not the major determinant of plasma lipid levels in childhood. Its impact is expressed only on high cholesterol background.
mesh_terms: D002648:Child; D002784:Cholesterol / Q000097:blood*; D002790:Cholesterol 7-alpha-Hydroxylase / Q000235:genetics*; D005838:Genotype; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood / Q000235:genetics*; D008055:Lipids / Q000097:blood; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics
chemical_list: D008055:Lipids; D002784:Cholesterol; D002790:Cholesterol 7-alpha-Hydroxylase