Genetics of pre-pubertal growth: a longitudinal study of Japanese twins

Genetic factors explain a major part of the variation of adult stature, but little is still known on the genetics of growth, especially in non-Caucasian populations.

To analyse the quantitative genetics of pre-pubertal growth in Japanese children.

Data from birth until 11 years of age were collected on 349 complete twin pairs based on previously recorded height measures. The data were analysed using two different multivariate models by the Mx statistical package.

No major sex differences were found and thus boys and girls were analysed together. Since 1 year of age, genetic factors explained from 42-71% and environmental factors shared by co-twins from 14-33% of the variation of height. Genetic continuity of height was high and 75% of the genetic variance was shared since 1 year of age. Environmental factors affecting height showed weaker correlations between early and late childhood than genetic factors.

Growth from early to late childhood is largely regulated by the same set of genes. However, also environmental factors shared by co-twins are important for growth. Identifying specific environmental factors affecting growth has potentially important public health implications, even in an affluent society such as Japan.