Examining DNA from 35,000 people, the researchers found that just one single letter in the human genetic code is likely responsible for making someone short, or tall, researchers said.
Scientists believe that inheriting a form of the gene HMGA2 that also carries the letter C in the genetic code instead of T will add a quarter of an inch in height. Two copies of the gene can result in a height increase of 2 inches.
One of the study’s lead authors, Dr Tim Frayling of the Peninsula Medical School in Exeter, said that everyone carries two copies of the HMGA2 gene and that about 25 per cent of white Europeans will carry both versions of the “tall” gene and another 25 per cent will carry both versions of the “short” gene.
He said: “Height is a typical ‘polygenic’ trait. In other words many genes contribute towards making us taller or shorter. Clearly our results do not explain why one person will be 6ft 5ins and another only 4ft 10ins. This is just the first of many – possibly as many as several hundred – that will be found. Even though improved nutrition means that each generation is getting successively taller, variation in height within a population is almost entirely influenced by our genes.”
“Because height is a complex trait, involving a variety of genetic and non-genetic factors, it can teach us valuable lessons about the genetic framework of other complex traits such as diabetes, cancer and other common human diseases,” says JoelHirshhorn, a senior researcher on the study.
The study was carried out by scientists at Harvard University and Children’s Hospital Boston along with U.K. researchers at Oxford University and the Peninsula Medical School in Exeter.
Source : Ontario Now