Variation of the platelet glycoprotein IIIa PI(A1/A2) allele frequencies in the three ethnic groups of Singapore.
BACKGROUND
Polymorphisms of the glycoprotein IIIa receptor have been shown to be associated with differences in platelet aggregability. The PI(A2) variant of the polymorphism has been reported to be an inherited risk factor for acute coronary events. Although the allele frequency of this polymorphism is well documented in Caucasian populations, studies involving Asian Indians, Malays and Chinese are lacking. We studied 706 random male individuals to determine the genotypic distribution of this polymorphism in Singapore.


METHODS
Male subjects included in this study were drawn from those undergoing routine annual medical examinations offered by their employers. Venous blood was obtained from these patients after an overnight fast and from which genomic DNA was extracted. Genotyping was carried out by polymerase chain reaction (PCR) followed by digestion with restriction enzyme NciI. Personal and family medical history of the subjects were also taken.


RESULTS
The genotype distribution of the individuals studied was in accordance to a population at Hardy Weinberg equilibrium. The frequency of the PI(A2) allele was 0.1, 0.01 and 0.01 in the Indians, Malays and Chinese, respectively. The differences in frequencies of the PI(A2) variant are significant among different ethnic groups (P<0.001 for Indians vs. Chinese and Indians vs. Malays).


CONCLUSIONS
We observed a significantly higher frequency of the PI(A2) allele among Indians relative to the Chinese and Malays in Singapore. The effect of this genotype may partially explain the higher rate of ischaemic heart disease seen among Indians compared to the Chinese and Malay ethnic groups.
Lim
Jimmy
J
Tan Tock Seng Hospital, Singapore, Singapore.
Lal
Suman
S
Ng
Kenneth C
KC
Ng
Kheng-Siang
KS
Saha
Nilmani
N
Heng
Chew-Kiat
CK
D000328:Adult; D044466:Asian People / Q000235:genetics*; D016009:Chi-Square Distribution; D002681:China / Q000208:ethnology; D003327:Coronary Disease / Q000235:genetics; D005787:Gene Frequency; D005828:Genetics, Population; D005838:Genotype; D006801:Humans; D007194:India / Q000208:ethnology; D039661:Integrin beta3 / Q000235:genetics*; D008296:Malaysia / Q000208:ethnology; D008297:Male; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012846:Singapore
D039661:Integrin beta3