OBJECTIVETo study the method for measuring familial correlations of quantitative trait and analyzing family data set of body height.

METHODSGeneralized estimating equation 2 (GEE2) was employed to estimating both regression coefficients and the familial correlation. Analyses was carried out on software MAREG. A example from height pedigrees illustrated the method.

RESULTSGEE2 provided robust estimations of regression coefficients and familial correlations simultaneously. In body height the correlations between parents and offspring (r = 0.459) and between siblings (r = 0.671) were significantly higher than those between two parents (r = 0.184) after adjusting gender, residence and birth age. Of the same types of relative pairs, the correlation between pairs with individuals of the same gender (eg. father-son r = 0.603, mother-daughter r = 0.456, male sibling r = 0.947, female sibling r = 0.681) was higher than those individuals of different gender (eg father-daughter r = 0.431, mother-son r = 0.364, sibling with different gender r = 0.530).

CONCLUSIONGEE2 should be considered a standard method for the investigation of familial aggregation due to its flexibility and robustness.