[Polymorphism (RFLP-PstI) of the apoprotein A-I gene in a healthy population. Its relation to high-density lipoproteins].

Background: Some RFLPs for the genes encoding for apoproteins have been associated with dyslipidemia and the predisposition to atherosclerosis. It is of interest to investigate the apo A-I gene in a Mediterranean population, since it is the major protein in HDL.

Methods: We studied the A-I C-III A-IV gene cluster RFLP defined by the endonuclease Pst I in 149 healthy males randomly selected among industrial workers in Tarragona. The mean age was 40 +/- 7 years (range 20 to 62). We analysed cholesterol and triglycerides in plasma and the lipoprotein fractions (VLDL, IDL, LDL and HDL) obtained by ultracentrifugation. The RFLP was determined for the enzyme Pst I in the A-I C-III A-IV gene cluster by the Southern blotting method.

Results: The genotype distribution was P1P1 81.9%, P1P2 14.8% and P2P2 3.4% and the allelic frequency was P1 89.3% and P2 10.7%. The plasma cholesterol, triglycerides, apo A-I and apo B did not show significant differences between these groups. The P2P2 subjects had lower HDL-C values (P1P1 1.17 +/- 0.39 mmol/l, P1P2 1.16 +/- 0.28 mmol/l y P2P2 0.89 +/- 0.14 mmol/l; p < 0.01).

Conclusions: The distribution of the genotypes in the Mediterranean population were similar to that observed in the USA and in Europe. P2P2 subjects had decreased HDL cholesterol but the low prevalence of the genotype being very low limits its value as a marker of coronary artery disease risk.