Abstract
In a combined Norwegian and British study of the age at death from coronary heart disease of heterozygotes for familial hypercholesterolaemia (FH) the correlation coefficients within families for 43 sib pairs was 0-70 and for 14 first cousin pairs 0-61. There was no significant correlation between the age at death and serum cholesterol concentration in either series. The intrafamilial correlations suggest that information about the age at death from coronary heart disease in heterozygotes within families may have some prognostic value and may also be interpreted as evidence for genetic heterogeneity in FH.