Scientists have known for a long time that heredity has something to do with a person's height but how genetics exactly influence a person's likelihood to grow tall or short is not clearly understood.
Findings of what to date is the largest research project on height-related genes reveal why some children grow up to be tall while others end up shorter than most of their peers. The results of the Genetic Investigation of Anthropometric Traits (GIANT) consortium, which was reported in journal Nature Genetics on Oct. 5, showed that genetics is responsible for about 80 percent of a person's height while the remaining 20 percent can be attributed to nutrition and other environmental factors.
In order to find single point mutations in the DNA that could have an impact on a person's height, Timothy Frayling, from the Genetics of Complex Traits at the University of Exeter Medical School in the U.K, and colleagues scanned the genomes of over 253,000 individuals from Europe, North America and Australia who have European ancestry.
By looking at approximately 2 million common genetic variants in the participants, the researchers identified 697 genetic variants in 424 gene regions that are associated with height and which together contribute to 20 percent of height-related genetic variation.
The researchers identified genes that are known to be associated with factors for height such as those that play a role in skeletal growth and collagen as these were mutated in individuals with short stature. They have also identified genetic regions that were not previously believed to be associated with height such as a gene that is involved in cell growth but not linked with skeletal functions.
"We identified several genes and pathways not previously connected with human skeletal growth, including mTOR, osteoglycin and binding of hyaluronic acid," Frayling and colleagues wrote. "Our results indicate a genetic architecture for human height that is characterized by a very large but finite number (thousands) of causal variants."
The researchers said that the results of the study help shed more light on human biology and could have an impact on the treatment of diseases that are influenced by height including cancer or osteoporosis.
"Our results suggest that massive human genetic studies, possibly into the millions, will continue to uncover all the subtle effects of our genetic variation that influence our health, behavior, body shape and all aspects of what makes us who we are," said study author Andrew Wood, from the University of Exeter Medical School.