(TTA)n repeat polymorphism in the HMG-CoA reductase gene and cholesterolaemia

Background: Hypercholesterolaemia is one of the main risk factors of athero sclerosis. Both environmental and genetic factors have been implicated in t he development of hypercholesterolaemia. The enzyme hydroxymethylglutaryl-c oenzyme A (HMG-CoA) reductase plays an important role in cholesterol synthe sis. Thus we supposed that polymorphisms in this gene could influence chole sterolaemia. Patients and methods: Using PCR, we measured the (TTA)(n) repeat polymorphi sm near the Alu sequence of the gene for HMG-CoA reductase in two groups of children selected from opposite ends of the cholesterolaemia distribution curve obtained from measuring cholesterolaemia in 2000 children. Eighty-two children in high- and eighty-six children in low-cholesterolaemic groups p articipated on the study. Results: A significant difference was found in the frequencies of the genot ypes of the 10+ odd alleles (43.9% in high-cholesterolaemic children vs 24. 4% in low-cholesterolaemic children p < 0.025). No differences were demonst rated in the frequencies of other genotypes (allele 10 + even and without a llele 10). No associations between lipid parameters and genotypes or genoty pe subgroups within the group of high- and low-cholesterolaemic children we re found. Conclusion: The (TTA)(n) repeat polymorphism in the gene for HMG-CoA reduct ase could be another genetic marker that plays a role in the genetic determ ination of cholesterolaemia.