Rakhi Sasidharan Nair1, Roshni Hareendra Babu2, Shajee Sivasankaran Nair3, Saboora Beegum4
BACKGROUND
Coronary artery disease is multifactorial in origin. Coronary artery disease
predisposition is attributed to genetic factors also. Many gene polymorphisms are
implicated out of which paraoxonase 1 (PON 1) gene is an important one. The
product of paraoxonase gene is paraoxonase enzyme which is seen in serum
associated with high density lipoprotein (HDL). This enzyme is mainly synthesised
by the liver. The protective effect of HDL is attributed to the presence of such
enzymes on it. Gln to Arg polymorphism at position 192 confers a risk of
developing atherosclerosis and coronary artery disease (CAD). This study is done
to assess the genotype distribution of PON 1 gene in CAD patients compared to
healthy controls in a population from Kerala.
METHODS
The case group consists of 100 angiographically proven CAD patients with no
history of hypertension, diabetes mellitus, hepatic disease or smoking. The control
group had 100 healthy controls from the general population. PON 1 gene was
amplified by a polymerase chain reaction (PCR) technique already reported and
restriction fragment length polymorphism by the restriction enzyme Alwl was done
to assess the polymorphism.
RESULTS
In this study, the frequency of heterozygous genotype QR was 86 % in control
and 76 % in cases. Though there was no significant difference in allele distribution
of Q or R, RR genotype was significantly higher in the case group (2 = 8.82; p
value = .012). With binary logistic regression model, adjusting for age and sex,
RR genotype is independently associated with CHD. Adjusted odds ratio of RR was
5.24 with 95 % confidence interval (CI) 1.41 - 19.47 for developing CHD (p <
0.05).
CONCLUSIONS
The RR genotype is more frequently seen in CAD patients than in controls. The
QR genotype is more frequent than QQ or RR in both cases and controls.
