There’s a whole lot of science — make that DNA changes — behind human height.
A new large-scale international study has just found 83 new genetic variations that control height in humans. Of these, some influence adult height by over 2 centimeters or nearly 8/10 of an inch. This is an enormous discovery, according to researchers.
“The genes affected by these genetic variations modulate, among other things, bone and cartilage development and growth hormone production and activation,” said University of Montreal professor and co-lead author Dr. Guillaume Lettre in a statement.
New DNA Changes Found To Govern Height
The largest and deepest search to date on the matter, the Genetic Investigation of Anthropometric Traits (GIANT) consortium involved over 300 researchers and 700,000 participants.
In 2014, the consortium studied roughly 250,000 individuals and brought the known number of genetic variations to almost 700, situated in over 400 spots in the genome. In this new study, the researchers used a different technique called ExomeChip, which tested for a database of almost 200,000 known variants that are rarer and alter the functioning of protein-coding genes. Most of these variants had not been tested in previous genetic research on height.
To find out the 83 gene variants, the team measured the presence of 250,000 genetic variations in the 700,000 subjects. Fifty-one of there are “low-frequency” or detected in less than 5 percent of people, while 32 are rare variants seen in less than 0.5 percent.
According to the new results, 27.4 percent of height’s heritability is no accounted for, or an increase from 20 percent in earlier research. Of the just-discovered variants, 24 influence height by over 1 centimeter or 4/10 of an inch, which is bigger than usually seen with the usual variants.
“In recent years, we identified several changes in DNA (i.e., genetic variations) associated with height, but their individual effects are low, influencing height by only one millimeter," Lettre explained.
The rare variants not only exhibited a large influence on height but also clued in on dozens of genes as crucial for skeletal growth. Genes such as SUSD5, GLT8D2, and LOXL4 had been already known but not previously linked to such growth. Carriers of the two different DNA changes in STC2 gene, for example, were 1 to 2 centimeters taller than non-carrier.
Complex Genetics Of Height
Convinced that their genetic method works, the researchers said they can now better identify similar gene variants that may govern the risk for certain diseases, including cancer, diabetes, and cardiovascular disease.
"Mastering the complex genetics of height may give us a blueprint for studying multifactorial disorders that have eluded our complete understanding, such as diabetes and heart disease," said Joel Hirschhorn, Harvard professor and co-lead author of the study.
Science can probe whether drugs that block STC2 gene activity could affect growth, Lettre cited as an example.
The findings were discussed in the journal Nature.
In 2015, a Swedish study found that tall people were more likely to get cancer than the rest of the population. Based on data from 5 million people in Sweden, the research saw that for every 4 inches over 3 feet, 3 inches that one stands, the odds of developing cancer climbed by 10 percent for men and 18 percent for women.
