Is height determined by genetics?
Approximately 80 percent of an individual's height is determined by inherited genetic variations, with environmental factors playing a smaller role.
Genetic Influence
Scientists estimate that about 80 percent of an individual’s height is determined by the DNA sequence variations they have inherited. For most individuals, height is controlled by a combination of many genetic variants that each have modest effects, a pattern known as polygenic inheritance. More than 700 such gene variants have been discovered, many of which affect cartilage in growth plates—areas in the long bones where new bone is produced to lengthen the limbs during childhood.
Rare Genetic Variants
Some rare gene variants have dramatic effects on height. Researchers have identified hundreds of genes involved in rare disorders that significantly impact stature, including:
- FGFR3: Variants cause achondroplasia.
- FBN1: Associated with acromicric dysplasia, geleophysic dysplasia, and Marfan syndrome.
- GH1: Associated with isolated growth hormone deficiency.
- EVC: Associated with Ellis-van Creveld syndrome and Weyers acrofacial dysostosis.
- GPC3: Associated with Simpson-Golabi-Behmel syndrome.
Some genes, such as ACAN, contain rare variants that cause severe growth disorders, as well as other variants with milder effects on height in individuals without a related health condition.
Environmental and Biological Factors
While genetics is the primary determinant, height is also influenced by environmental factors, including:
- Prenatal environment: A mother's nutrition during pregnancy, smoking, and exposure to hazardous substances.
- Childhood health: Nutrition, physical activity, access to healthcare, and the presence of infectious diseases.
- Socioeconomic factors: Income, education, and occupation.
Studies on immigrant families suggest that some differences in height between ethnicities are explained by non-genetic factors, as moving to a country with better access to nutrition and healthcare can substantially influence the height of the next generation.