Polymorphisms of the Transforming Growth Factor-β1 Gene in Relation to Myocardial Infarction and Blood Pressure

Abstract

Transforming growth factor-β1 (TGF-β1) plays an important role in the modulation of cellular growth and differentiation and the production and degradation of the extracellular matrix. A number of experimental results suggest that TGF-β1 may be involved in cardiovascular physiopathology. In the present study, we assessed whether the TGF-β1 gene is a candidate gene for coronary heart disease or hypertension. We screened the coding region and 2181 bp upstream of the TGF-β gene for polymorphisms and identified seven polymorphisms: 3 in the upstream region of the gene at positions −988, −800, and −509 from the first transcribed nucleotide; 1 in a nontranslated region at position +72; 2 in the signal peptide sequence Leu 10 →Pro, Arg 25 →Pro; and 1 in the region of the gene coding for the precursor part of the protein not present in the active form, Thr 263 →Ile. We analyzed these TGF-β1 polymorphisms in 563 patients with myocardial infarction and 629 control subjects from four regions in Northern Ireland and France. The Pro 25 allele was more frequent in patients than in control subjects in Belfast ( P <.01) and Strasbourg ( P <.05). The TGF-β1 polymorphisms were not associated with the degree of angiographically assessed coronary artery disease in patients. The presence of a Pro 25 allele was associated with a lower systolic pressure in the four control groups ( P <.002), and a history of hypertension was significantly less frequent in homozygotes or heterozygotes for Pro 25 than in homozygotes for Arg 25 (odds ratio, 0.43; 95% confidence interval, 0.19 to 0.92; P <.03). Since the Pro 25 allele was associated with an increased risk of myocardial infarction and a reduced risk of hypertension, we favor a cautious interpretation of these apparently inconsistent results. Other studies will need to verify whether these associations are real.