We used nondenaturing polyacrylamide gradient gel electrophoresis to examine the familial correlations of high density lipoprotein (HDL) subclasses for 150 offspring in 47 nuclear families. The absorbance of protein stain was used as an index of mass concentrations at intervals of 0.01 nm within five HDL subclasses: HDL3c (7.2-7.8 nm), HDL3b (7.8-8.2 nm), HDL3a (8.2-8.8 nm), HDL2a (8.8-9.7 nm), and HDL2b (9.7-12 nm). Parent-offspring correlations were computed for two different characterizations of the parents: 1) by sex (i.e., mother versus father) and 2) by their relative values (highest versus lowest HDL). Sibling resemblance was assessed by using the intraclass correlations coefficient. Family members were significantly related for the following subclasses: HDL3c (sibling and father-offspring), HDL3b (sibling), HDL3a (sibling and mother-offspring), HDL2a (mother-offspring), and HDL2b (sibling, father-offspring, and mother-offspring). The offsprings' HDL3c and HDL2b values were more strongly related to their fathers' than to their mothers' values, whereas their HDL2a levels were more strongly related to their mothers' than their fathers' values. In addition, fathers' HDL2b levels were inversely correlated with the offsprings' HDL3b. The parents' HDL subclass levels were more strongly related to subclass levels of their younger (< or = 20 years) than their older offspring. Among all subclasses, HDL2b showed the strongest parent-offspring relation, with the parents' HDL values accounting for over 30% of the variance in offsprings' HDL2b.(ABSTRACT TRUNCATED AT 250 WORDS)