Meta-Analysis of the Heritability of Childhood Height From 560 000 Pairs of Relatives Born Between 1929 and 2004.

Background: Childhood height is commonly used to measure children's health and nutritional status. It is used to define stunting, where a child is considered stunted if their height is shorter than two standard deviations below the Child Growth Standards median. Studies have shown that genetic and environmental factors contribute to childhood height, so understanding these contributions is important for stunting research. This systematic review and meta-analysis examined the contribution of these factors across study designs and ancestries.

Methods: A systematic search found 28 twin and 26 family studies spanning from birth to 17 years. We identified 162 293 twin, 380 195 parent-offspring, and 19 965 sibling pairs born between 1929 and 2004. These datasets were meta-analyzed using a random effects model. The review is registered in PROSPERO (ID CRD42023432550).

Results: The estimated heritability (h) of height from twin design increased from birth to 17 years. For children under 5 years, the estimated heritability was 0.57 (95%CI, 0.52-0.61) for European, 0.48 (0.39-0.57) for Asian, and 0.46 (0.40-0.51) for multi ancestries. Heritability estimated from parent-offspring design was 0.46 (95%CI, 0.28-0.62) at birth and 0.76 (95%CI, 0.70-0.80) at 17 years. Meanwhile, the estimated heritability from sibling design remained constant across ages at 0.70 (95%CI, 0.52-0.83).

Conclusions: The heritability estimates of childhood height were slightly higher in European ancestries, but in general, they did not significantly differ across ancestry groups. While the shared environmental effects on height peak in early childhood, the estimated heritability increase in late teens. Unique environmental factors play a small, but significant role throughout childhood.