汉族儿童青少年体型遗传的双生子研究

目的分析遗传与环境因素对儿童青少年体型的影响,并探讨其中年龄和性别的作用。方法采用Heath-Carter法对376对6～18岁同性别汉族双生子（同卵双生子245对,异卵双生子131对）的体型三因子进行计算。调整另外两项体型因子后,用Mx软件拟合最佳模型,计算各体型因子的遗传与环境方差组分,分析年龄和性别的作用,并按体格突增分期估算不同发育期各因子的遗传度。结果校正年龄后,男生内、中、外三因子的遗传度分别为0．45,0．80,0．44;女生内、中、外三因子的遗传度分别为0．82,0．79,0．81;男生内因子的遗传度在青春期晚期明显高于前期（t=4．99,P〈0．01）和早期（t=6．16,P〈0．01）,外因子的遗传度在青春期晚期明显低于前期（t=3．35,P〈0．01）和早期（t=4．12,P〈0．01）;女生内因子（t=2．77,P〈0．01）、中因子（t=2．08,P〈0．05）的遗传度均为青春期前期明显高于早期。结论遗传因素对女生体型的影响明显高于男生,尤以内因子和外因子最为明显,男生中因子主要受遗传因素影响,内、外因子受环境因素影响较大。不同发育阶段对体型各因子遗传度的影响应引起重视。

Genetic study on somatotype of child and adolescent twins in Han nationality

Objective To assess the genetic and environmental influences on the somatotype of children and adolescents,and the effects of sex and age.Methods The components of somatotype were calculated by using Heather-Cater method in a total of 376 twin pairs of Han nationality,including 245 monozygotic(MZ) and 131 like-sex dizygotic(DZ) twin pairs aged 6 to 18 years.Model-fitting method by Mx package was performed to evaluate the proportion of variance components and to analyze the effects of sex and age on each component of somatotype using the adjusted data for other two somatotype components.The heritability of each component in different development periods divided by growth spurt was also evaluated.Results The estimated heritabilities of endomorphic,mesomorphic and ectomorphic components were 0.45,0.80,0.44 in boys,0.82,0.79 and 0.81 in girls respectively after adjusting age.In boys,the heritability of endomorphic component during late puberty was significantly higher than that during pre-puberty(t=4.99,P<0.01) and puberty(t=6.16,P<0.01),while the heritability of ectomorphic component during late puberty was significantly lower than that during pre-puberty(t=3.35,P<0.01) and puberty(t=4.12,P<0.01.In girls,the heritability of endomorphic(t=2.77,P<0.01) or mesomorphic(t=2.08,P<0.05) component during pre-puberty was significantly higher than that in early puberty.Conclusion The genetic influence on somatotype of girls should be much more than that of boys,especially on the endomorphic and ectomorphic components.For boys,the mesomorphic component is mainly determined by genetic factors,but the other components are mainly affected by environmental ones.The effects of the development periods on the heritability of somatotype should be paid much attention to.