Allelic frequencies of polymorphic variants at the lipoprotein lipase gene locus on chromosome 8 have been measured in subjects with premature coronary heart disease and/or dyslipidemia. One of the polymorphic variants involves a termination codon in exon 9 at the position of serine 447, which produces a truncated protein. Michaelis constants and Vmax for triolein and chylomicrons appear identical for the variant and native enzymes. Another informative polymorphism is a Hind 111 restriction site in intron 8 that shows marked asymmetric allelic distribution in subjects with hypertriglyceridemia/low-high-density lipoprotein and in subjects with premature coronary heart disease. It is hoped that this marker may lead to the identification of an etiological mutation in its vicinity to account for these disease associations.