POLYMORPHISM IN APOLIPOPROTEIN(A) KRINGLE IV-37 (MET THR) - FREQUENCYIN A LONDON POPULATION AND ITS ASSOCIATION WITH CORONARY-ARTERY DISEASE/

Background: A raised concentration of lipoprotein(a) [Lp(a)] in human plasma has been considered as a risk factor for coronary artery diseas e (CAD). Apolipoprotein(a) and plasminogen genes are exceptionally sim ilar to a variable number of plasminogen-like kringle IV repeats in th e apo(a) gene. Polymorphisms have been previously identified in the ap olipoprotein(a) kringle IV 37. Hypothesis: In order to determine the f requency of the apolipoprotein(a) kringle IV 37 Met(66)-->Thr polymorp hism in a London-based population and to assess the relationship of th is polymorphism with CAD in Caucasian patients, we genotyped two group s of people of different ethnic origin (Caucasian and Afro-Caribbean) for the mutation using standard polymerase chain reaction (PCR) techni ques. Methods: The first group consisted of 182 unrelated Caucasian pa tients (107 men and 75 women, mean age 59.7 +/- 10.2 years) recruited at St. George's Hospital. They were defined as patients with 0, 1 or g reater than or equal to 2 vessel disease patients depending on the deg ree of stenosis in none, one, or several major epicardial arteries. Th e second group comprised 64 unrelated patients of Afro-Caribbean origi n attending a hypertension clinic at St. George's Hospital. Results: I t was shown that the prevalence of the Met(66)-->Thr mutation is marke dly higher in Caucasians than in Afro-Caribbeans and that this mutatio n is not associated with either Lp(a) levels or severity of CAD.