Towne B, Siervogel R M, Blangero J
Department of Community Health, Wright State University School of Medicine, Dayton, Ohio 45435, USA.
Genet Epidemiol. 1997;14(6):1053-8. doi: 10.1002/(SICI)1098-2272(1997)14:6<1053::AID-GEPI82>3.0.CO;2-G.
Genotype-by-sex (G x S) interaction refers to the interaction of autosomal genes with male or female physiological "environments." G x S interaction has been demonstrated in quantitative genetic analysis of a variety of traits including serum lipid concentrations and anthropometrics, and the importance of considering sex-specific major gene effects in segregation analyses also has been demonstrated. The goal of this study was to examine the effects of G x S interaction on the power to detect linkage. Trait Q3 in GAW10 Problem 2 was analyzed because it was modeled to have G x S interaction at the major gene locus MG3. All 200 nuclear family and 200 extended pedigree replicates were first screened for the presence of G x S interaction in Q3 using a quantitative genetic method. More than half of both the nuclear family and extended pedigree replicates evidenced significant G x S interaction. Variance components linkage analysis was then performed using all markers on GAW10 chromosome 4 in all 200 nuclear family and 200 extended pedigree replicates. A peak lod score of 1.92 at the correct chromosomal location was obtained using the extended pedigree data and incorporating G x S interaction effects. Not incorporating G x S interaction lowered the peak lod score from the analyses of the extended pedigrees to 1.53. Incorporation of G x S interaction effects also increased the power to detect linkage in the nuclear family replicates, although the nuclear families had considerably less power than the extended pedigrees to detect linkage, whether or not G x S interaction was modeled. Incorporation of G x S interaction effects can increase the power to detect linkage, even when the G x S interaction effects are modest.
基因-性别（G×S）相互作用是指常染色体基因与男性或女性生理“环境”之间的相互作用。G×S相互作用已在包括血脂浓度和人体测量学在内的多种性状的数量遗传学分析中得到证实，并且在分离分析中考虑性别特异性主基因效应的重要性也已得到证实。本研究的目的是检验G×S相互作用对检测连锁的效能的影响。对GAW10问题2中的性状Q3进行了分析，因为它被设定为在主基因座MG3处存在G×S相互作用。首先使用定量遗传学方法对所有200个核心家庭和200个扩展家系重复样本进行筛选，以检测Q3中是否存在G×S相互作用。超过一半的核心家庭和扩展家系重复样本都显示出显著的G×S相互作用。然后，对所有200个核心家庭和200个扩展家系重复样本，使用GAW10第4号染色体上的所有标记进行方差成分连锁分析。使用扩展家系数据并纳入G×S相互作用效应，在正确的染色体位置获得了1.92的最高对数优势分数。不纳入G×S相互作用会使扩展家系分析中的最高对数优势分数降至1.53。纳入G×S相互作用效应也增加了在核心家庭重复样本中检测连锁的效能，尽管无论是否对G×S相互作用进行建模，核心家庭检测连锁的效能都比扩展家系低得多。纳入G×S相互作用效应可以增加检测连锁的效能，即使G×S相互作用效应较小。
