In this article we report a novel statistically significant association between the D4.7/D4.7 genotype of the DRD4 gene and the body mass of black and Hispanic participants in the National Longitudinal Study of Adolescent Health (Add Health). We investigated the role of the 48-bp repeat polymorphism of the dopamine receptor 4 gene (DRD4) in body mass regulation in 2,277 adolescents and young adults followed in 1995 (12-18 years old), 1996, and 2002 by Add Health. After the effects of age, sex, and ethnicity were adjusted, the D4.7/D4.7 genotype reduced the body mass index (BMI)-percentile score by 15 and 12.5, as compared to those with other genotypes, for African-Americans (P = 0.0047) and Hispanic-Americans (P = 0.037), respectively. Although the D4.7/D4.7 genotype was associated with a lower BMI-percentile score in white individuals compared to other genotypes, the difference was not significant. Individuals heterozygous for D4.7 did not differ from those with the other/other genotype.
2006 Wiley-Liss, Inc.