Segregation analysis of serum uric acid in the NHLBI family heart study

Segregation analysis was performed on the serum uric acid measurements from 523 randomly ascertained Caucasian families from the NHLBI Family Heart St udy. Gender-specific standardized residuals were used as the phenotypic var iable in both familial correlation and segregation analysis. Uric acid resi duals were adjusted for age, age(2), age(3), body mass index (kg/m(2)), cre atinine level, aspirin use (yes/no), total drinks (per week), HOMA insulin resistance index [(glucose * insulin)/22.5], diuretic use (yes/no), and tri glyceride level. Sibling correlations (r=0.193) and parent-offspring correl ations (r=0.217) were significantly different from zero, but these two fami lial correlations were not significantly different from one another. After adjustment for covariates, the heritability estimate for serum uric acid wa s 0.399. Segregation analysis rejected the "no major gene" model but was un able to discriminate between an "environmental" and a "Mendelian major gene " model. These results support the hypothesis that uric acid is a multifact orial trait possibly influenced by more than one major gene, modifying gene s, and environmental factors.