Source: Guardian
Date: 3 September 2007

Scientists find a gene that makes some people taller

Ian Sample, science correspondent

The first gene linked to tallness, one of the most heritable of traits, has been discovered by scientists, a finding that is expected to shed light on human development and further understanding of cancer. An international team including researchers at Oxford and Exeter analysed DNA from 35,000 people and found that a single letter in the human genetic code was responsible for making some people taller than others.

The scientists zeroed in on a gene called HMGA2, of which we inherit two copies, one from each parent. Inheriting a form of the gene that has a C written into the genetic code instead of a T adds about half a centimetre to a person's height, the scientists found, while inheriting two copies adds nearly a full centimetre.

The discovery is the first to identify a single gene that directly influences natural variation of height. Around a quarter of white Europeans will carry two versions of the "tall" version of the gene, with another quarter carrying two "short" versions.

Scientists at Harvard University and Children's Hospital Boston joined British researchers at Oxford University and the Peninsula Medical School in Exeter to scour the genomes of 5,000 white European patients who had volunteered DNA samples and details of their height and weight for medical studies into diabetes and heart disease. The scientists identified the HMGA2 gene as playing a major role in height variation and noted that changing just one letter in the genetic code had a significant effect on growth. The discovery was confirmed by searching for the same two versions of the gene in a further 30,000 patients.

"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," said Joel Hirshhorn, a senior researcher on the study, which appeared in Nature Genetics yesterday.

A study published in 2005 suggests that HMGA2 is fundamental to human growth and may play a role in tumour formation. An eight-year-old boy with a damaged version of the gene had multiple tumours and stood 5ft 6ins tall, the average height of a 15-year-old boy. Tall people are known to be more at risk of certain cancers, such as prostate, bladder and lung, and are also more at risk of osteoporosis.

Tim Frayling, a geneticist at Peninsula Medical School and co-author of the study, said the team expects that tens to hundreds more genes linked to height will be identified within the next year.