Background. - The PI(A2) polymorphism of GPIIIa has been associated with unstable coronary syndromes in some studies, but the association has remained debated. None of the previous studies have focused on families at high risk. Risk factors tend to cluster within kindreds with high prevalence of premature coronary heart disease (CHD). Therefore, a heightened prevalence of the PI(A2) polymorphism among siblings of patients with CHD would support the hypothesis that PI(A2) is linked, directly or indirectly, to CHD. Objectives. - To measure the prevalence of the PI(A2) polymorphism among siblings of patients with CHD before the age of 60 years and to seek an association between the PI(A2) polymorphism and established atherosclerotic and thrombogenic risk factors. Methods. - From January 1994 to April 1996, we genotyped 116 asymptomatic siblings (60 Caucasians, 56 Afro-Caribbeans) of patients with CHD manifestations before the age of 60 years for the PI(A) polymorphism (also called HPA-1). A control cohort was used for comparison, consisting of individuals that were matched for race and geographic area but were free of CHD (n = 268, 168 Caucasians and 100 Afro-Caribbeans). In addition, we have characterized the sibling cohort for other-atherogenic and thrombogenic risk factors. Results. - The prevalence of pI(A2)-positive individuals (PI(A2)[+], PI(A1/A2) heterozygotes plus PI(A2/A2) homozygotes) in the sibling cohort was high: 41.4%. When analyzed separately, the prevalence of PI(A2)(+) siblings was 53.3% among Caucasians and 28.6% among Afro-Caribbeans. There was no association between PI(A2) and other restablished atherogenic or thrombogenic risk factors. Interestingly, the clustering of other risk factors was lesser among PI(A2)(+) siblings than their PI(A1) counterparts. Conclusions. - This study supports the hypothesis that the prevalence of PI(A2)(+) individuals is high in kindreds with premature CHD. Hence, like the established risk factors that tend to cluster in families with premature CHD and contribute strongly to the accelerated atherosclerotic process affecting these individuals, the PI(A2) polymorphism of GPIIIa may represent an inherited risk that promotes the thromboembolic complications of CHD. That these asymptomatic PI(A2)(+) siblings had overall less established risk factors than their PI(A1) counterparts might represent an explanation for why they remained asymptomatic despite their PI(A2) positivity.
|Original language||English (US)|
|Number of pages||7|
|Journal||Archives of Pathology and Laboratory Medicine|
|State||Published - Jan 1 1999|
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Medical Laboratory Technology