The study, which was recently published in the journal Nature, is the largest genome-wide association study ever conducted, using the DNA of nearly 5 million individuals from 281 contributing studies. It fills a significant gap in our knowledge of how genetic differences contribute to height differences. Over one million research participants are of non-European heritage (African, East Asian, Hispanic, or South Asian).
The 12,111 variants that cluster around areas of the genome involved with skeletal growth offer a strong genetic predictor of height. For people of European ancestry, the identified variants account for 40% of the variance in height, and for those of non-European ancestry, 10–20%.
Adult height is mostly determined by the information encoded in our DNA; children of tall parents are likely to be taller, while children of short parents tend to be shorter, although these estimations aren’t perfect. The development of a small baby into an adult, as well as the role of genetics in this process, has long been a complicated and poorly understood aspect of human biology. The previous largest genome-wide association study on height employed a sample size of up to 700,000 people; the current sample is around seven times larger than earlier studies.
The study, which is being conducted at a scale never before seen, offers new levels of biological detail and understanding of why individuals are tall or short, with heredity being connected to various specific genomic regions. The results demonstrate that regions comprising just over 20% of the genome contain the majority of the gene variants linked to height.
The study’s findings could help doctors identify people who cannot reach their genetically predicted height, which may aid in the diagnosis of hidden diseases or conditions that may be stunting their growth or impacting their health. The research also provides a valuable blueprint on how it could be possible to use genome-wide studies to identify a disease’s biology and subsequently its hereditary components.
While this study has a large number of participants from non-European ancestries compared to previous studies, the researchers emphasize the need for more diversity in genomic research.
Most of the genetic data available are from people of European ancestry, so genome-wide studies don’t capture the wide range of ancestral diversity across the globe. Increasing the size of genome-wide studies in non-European ancestry populations is essential to achieve the same saturation level and close the gap in prediction accuracy in different populations.
Dr. Eirini Marouli, a co-first author of the study and Senior Lecturer in Computational Biology at Queen Mary University of London, said: “We have accomplished a feat in studying the DNA of over 5 million people that was broadly considered impossible until recently.”
She continues, “Genomic studies are revolutionary and might hold the key to solving many global health challenges – their potential is tremendously exciting. If we can get a clear picture of a trait such as height at a genomic level, we may then have the model to better diagnose and treat gene-influenced conditions like heart disease or schizophrenia, for example. If we can map specific parts of the genome to certain traits, it opens the door to widespread targeted, personalized treatments further down the line that could benefit people everywhere.”