Guo Guang, Tong Yuying
Department of Sociology and Carolina Population Center, University of North Carolina at Chapel Hill 27599-3210, USA.
Demography. 2006 Nov;43(4):747-69. doi: 10.1353/dem.2006.0029.
We carried out two distinct types of genetic analysis with data from the National Longitudinal Study of Adolescent Health. The first was a non-DNA twin analysis using monozygotic (identical) and same-sex dizygotic (fraternal) twins. The second analysis investigates the association between age at first sexual intercourse and the 48-bp repeat polymorphism in the dopamine receptor D4 gene (DRD4). The twin analysis shows that MZ twins correlate their timing of first sex to a much greater extent than do the same-sex DZ twins. Our analysis of the polymorphisms in DRD4 indicates that those with an any-3R genotype experienced a risk of first sexual intercourse 23% (p = .016), 233% (p = .0001), 28% (p = .012), and 69% (p = .006) higher than those with an other/other (or any-4R) genotype in the all-ethnicities (n = 2,552), Asian, white, and Hispanic samples, respectively. The risk of first sex does not differ between the two genotypes in the African American sample. These results were obtained after adjusting the standard socioeconomic covariates, including gender, parental education, family structure, and community poverty in the regression model. Evidence from both twin and genetic-variant analyses points to a role of genes in the timing of first sexual intercourse.
我们利用青少年健康全国纵向研究的数据进行了两种不同类型的基因分析。第一种是使用同卵（ identical ）双胞胎和同性异卵（ fraternal ）双胞胎的非DNA双胞胎分析。第二种分析调查首次性交年龄与多巴胺受体D4基因（ DRD4 ）中48碱基对重复多态性之间的关联。双胞胎分析表明，同卵双胞胎在首次性行为时间上的相关性比同性异卵双胞胎大得多。我们对DRD4多态性的分析表明，在所有种族（ n = 2552 ）、亚洲、白人及西班牙裔样本中，具有任何3R基因型的个体首次性交的风险分别比具有其他/其他（或任何4R ）基因型的个体高23%（ p = 0.016 ）、233%（ p = 0.0001 ）、28%（ p = 0.012 ）和69%（ p = 0.006 ）。在非裔美国人样本中，两种基因型之间首次性交的风险没有差异。这些结果是在回归模型中调整了包括性别、父母教育程度、家庭结构和社区贫困等标准社会经济协变量后获得的。双胞胎分析和基因变异分析的证据均表明基因在首次性交时间上起作用。
