Tall tale: gene variants can add 2cm to your height

Researchers on Wednesday unveiled 83 rare gene variants which exert a strong influence on human height, with some capable of adding or subtracting more than two centimetres (0.8 inches).

The discovery could lead to drugs to make short people taller or vice versa, or tests to identify people at risk of developing growth disorders, the team reported.

More than 300 researchers from five continents trawled through genetic data from 711,428 people to find the variants.

Previous research had shown that genetic inheritance determines more than 80 percent of a person’s height. Non-genetic influences include nutrition, pollution and other environmental factors.

“Our latest discovery means that we can now explain over a quarter of the heritable factors involved in influencing a person’s height,” said Andrew Wood of the University of Exeter, a co-author of the study, published in the journal Nature.

Previous work had identified variants believed responsible for a fifth of height heritability, nearly 700 in total. These were common mutations that tend to have a smaller individual effect, typically altering stature by less than a millimetre.

Twenty-four of the 83 newly found variants can affect height by more than 1 centimetre, the team reported.

Genes are sections of DNA which carry codes or instructions to build the proteins an organism needs to function.

But sometimes the same gene varies from one person to the next, accounting for distinct features such as straight or curly hair, eye colour or skin tone.

To expand the list of height-related genes, Wood and a team used new technology to test participants for less common, hard-to-detect variations.

- Drug target -

They found that “one gene of particular interest, STC2, had two different DNA changes that both had larger effects on height,” said a statement from the Boston Children’s Hospital, which took part in the study.

Only about one in a thousand people carry one of these variants, and were 1-2 centimetres taller than non-carriers.

This made STC2 “a potential drug target for short stature,” said the hospital’s Joel Hirschhorn.

The newly discovered variants were implicated in gene regulation of bone and cartilage development, as well as growth hormone production and activation, the researchers said.

Scientists hope a better grasp of the genetics of height will shed light on how DNA predicts other, less obvious traits and disease risks: Who might have a heart attack despite a healthy lifestyle? Which children are more at risk of developing leukaemia?

Previous research had shown that tall people tend to be more successful in life.

They also have a greater risk of breast or prostate cancer, but a smaller risk of cardiovascular disease.