NO EVIDENCE FOR LINKAGE BETWEEN FAMILIAL HYPERTRIGLYCERIDEMIA AND APOLIPOPROTEIN-B, APOLIPOPROTEIN C-III OR LIPOPROTEIN-LIPASE GENES

Familial hypertriglyceridemia has been suggested to be an autosomal do minant condition with age-dependent penetrance, but so far the underly ing defective gene has not been elucidated. We examined the possible r ole of three candidate gene loci by linkage analysis in six Finnish fa milies with familial clustering of hypertriglyceridemia. The probands were initially recruited from a group of hyperlipidemic outpatients af ter measurement of serum triglyceride concentrations exceeding 2.00 mm ol/l on two occasions. Altogether, 71 subjects were included in the li nkage analyses. Bi- or multiallelic DNA polymorphisms were used as mar kers for the apolipoprotein B gene (chromosome 2), lipoprotein lipase gene (chromosome 8), and apolipoprotein A-I/C-III/A-IV gene cluster (c hromosome II). Linkage analysis was performed by applying two alternat ive phenotyping models, one adopting quantitative serum triglyceride c oncentrations and another using qualitative classification of the subj ects into hypertriglyceridemic, normotriglyceridemic, and borderline h ypertriglyceridemic groups. Using either approach, the cumulative lod scores of each of the three candidate genes in the six families were l ess than -2.0 at the recombination fraction 0.0. These results suggest that none of the candidate genes investigated is involved in familial clustering of hypertriglyceridemia in our study.