Summary
Coronary artery disease (CAD) is a multifactorial disease, and family history is the
best available tool to assess gene-environment interaction. This study addressed the
heritability of quantitative traits, namely lipid, coagulation/fibrinolysis and pro-inflammatory
markers in the ongoing family-based Indian Atherosclerosis Research Study and assessed
the effect of the type/lineage of CAD family history on inheritance patterns in the
highrisk Indian population. A total of 518 families comprising 2,305 individuals were
recruited in phase I of the IARS; of these, 1,195 individuals from 220 families were
included in the heritability analysis. With the exception of leptin, all phenotypes
exhibited significant age- and sex-adjusted heritability (p<0.0001). Amongst all the
phenotypes analysed after adjustment for confounding factors, the significantly higher
heritability estimates of triglycerides (0.53, p<0.0001), lipoprotein (a) (0.83, p<0.0001)
and interleukin-6 (0.46, p<0.0001) with low spouse pair correlations identifies them
as possible CAD risk factors. Families with parental history of CAD had onset of CAD
symptoms at much younger ages with significantly higher heritability of proinflammatory
markers, whereas in families with sibling history of CAD, more risk factors were present
at significantly higher levels. Triglycerides, lipoprotein (a) and interleukin-6 appear
to be promising atherothrombotic candidate phenotypes in this population. Genes controlling
these phenotypes are possible candidate genes linked with CAD. An informed understanding
and incorporation of ‘family history’ as a screening tool may help in the prevention
and pre-emption of CAD.
Keywords
Inflammation - SOLAR - atherosclerosis