[Contribution of genetic and environmental factors in the phenotypic variability of major indices of child development at different stages of postnatal ontogenesis].

Main indices of physical development of monozygotic and dizygotic twins were investigated during 13 years period. Using the coefficients of the within-pair correlation of characters studied an attempt was made to estimate the correlative contribution of genetic and environmental determinants to formation of phenotypic variance of height, weight and chest circumference from birth up to 13 years old. The indices of composing components obtained suggest that underlying formation of phenotypic variance of each of the characters analysed are the mechanisms reflecting qualitative, quantitative and time peculiarities of functioning of polygenic systems involved in determination of characters studied and peculiarities of their interaction with environmental factors.