Obesity gene is not linked with body mass index nor essential hypertension in African American Siblings.

The human homologue of the obesity gene (Ob) has recently been identified (Nature 1994;372:425-432). We analyzed linkage in moderately obese, African American siblings with essential hypertension using locus D7S1875, a tightly linked polymorphism (Genome Research 1995;5:5-12). We studied 147 hypertensive African Americans in 67 sibships. 98 were female, 49 male. Mean age was 50 ± 11 (sd). Mean body mass index (BMI) was 32.3 ± 7 kg/m2. Mean systolic and diastolic pressures were 145 ± 19 and 92 ± 13 on a mean of 1.7 anti-hypertensive medications. Heterozygosity score of this polymorphic marker was 0.90. The Sibpal subroutine of S.A.G.E. was used to analyze the data (U.S.P.H.S. Resource grant 1 P41 RR03655). Sibling pair linkage analysis using the log transformation of BMI as the quantitative trait showed: Affected sibling pair linkage analysis to determine linkage with the phenotype of essential hypertension showed: In conclusion, we could not demonstrate linkage with the phenotype of moderate obesity nor essential hypertension in African American hypertensive sibling pairs. However, we cannot exclude linkage in individuals with more severe obesity.