Dozens of rare DNA variants have been identified in the largest genetic study of human height in an Asian population. Published in Nature Communications, the genome-wide association study (GWAS) highlighted some of the similarities and differences that play a role in determining height in different parts of the world, and deepened our understanding of the interactions between genes that contribute to normal growth.

Height is a highly heritable trait under polygenic inheritance, meaning it is largely affected by several variants, not only one, and affected by the DNA we inherit from our parents. Numerous genome-wide association studies have shown that thousands of variants can affect height, with more than 3500 being identified so far. However, most large studies that have been performed are based on European populations.

Researchers at the Laboratory for Statistical Analysis at the RIKEN Centre for Integrative Medical Sciences (IMS) in Japan used the BioBank Japan Project, a collection of genetic and clinical data collected from nearly 200,000 individuals living across the country. Using this genetic data, they found some connections between adult height and some 28 million sites across the genome.

The researchers reported 573 height-associated variants, including 22 rare and 42 low-frequency variants. These 64 rare variants explain 1.7% of the phenotypic variance. As well as appearing to be specific to East Asians, the rare variants were found to be mostly linked to genes involved in increasing height, whereas any rare variants usually found in Europeans have the opposite effect and constrain height.

The results could suggest that European and Japanese populations experienced different evolutionary pressures in their distant pasts, including differences such as lifestyle which could have played a role.

The team hope that their research leads to the development of new methods to identify population-specific selection pressures on complex human traits and expand our genetic knowledge on population structure.