267对双生子机能和形态遗传度分析

An analysis of functional and morphological heritability of 267 twins

目的通过双生子分析法了解环境因素和遗传因素对儿童生长发育的影响。方法用相关系数法和变异方差计算遗传力。结果①双生子的生长发育规律与一般儿童一致，男女童在青春期有2个交叉形态指标；②身高、体重、臂围、收缩压、舒张压的遗传度估计分别为0．49、0．45、0．47、0．38、0．43；同卵双生子与父母身高的相关系数明显大于异卵双生子与父母之间的相关系数；异卵双生子与母亲的相关系数大于异卵双生子与父亲的相关系数；（D父母平均身高与子女平均身高的相关系数有加权作用；④在18岁内，儿子身高=2．77＋5．44×年龄＋0．25×父身高＋0．20×母身高；女儿身高=6．40＋3．50×年龄＋0．09×父身高＋0．50×母身高。结论①在3项形态指标变异中，环境与遗传均起重要作用；②身高是一个比较稳定的性状，遗传力较其他指标大。因此，它是一个可预测的指标；③血压的变异是遗传和环境共同作用的结果。

Objective To investigate influence of environmental factors and genetic factors on growth and development of children through twin study. Methods The correlation coefficient and variation variance were used to calculate heritability. Results （1）The growth regularity of the twins was identified with that of normal children. The morphological indexes of boys and girls had two crosses during their adolescence; （2）The heritability estimations of body height, body weight, upper arm circumference, systolic blood pressure and diastolic blood pressure of the twins were 0.49, 0.45, 0.47, 0. 38, 0.43 respectively. The correlation coefficient in body height between monozygotic twins and their parents was significantly larger than that between momo dizygotic twins and their parents. The correlation coefficient between dizygotic twins and their mother was larger than that between dizygotic twins and their father; （3） In the correlation coefficient of average body height between the parents and their children, there was a weighting effect; （4）Within 18 years old, the son＇ s body height = 2.77 ＋ 5.44 × age ＋ 0.25 × father＇ s body heihgt ＋ 0.20 × mother＇ s body height; the daughter＇ s body height = 6.40 ＋ 3.50 × age ＋ 0.09 x father＇ s body heihgt ＋ 0.50 ×mother＇ s body height. Conclusion （i）The environmental and genetic factors play important roles in variation of three morphological indexes ; （2）Body height is a relatively stable traits and its heritability is larger than other indexes, so it is a predictable index; （3）The variation in blood pressure is the result of synergetic effect of genetic and environmental factors.