London: As many as 83 new genetic variants may strongly influence how tall you are, according to the largest genetic study of adult height that analysed DNA from over 700,000 participants across the globe.
Adult height is mostly determined by the information encoded in our DNA - children from tall parents tend to be taller, and those from short parents are shorter. However, growth from a small baby into an adult, and the role of genetics, is one of the most poorly understood areas of human biology.
Hundreds of DNA changes that influence height have already been identified, but these common DNA changes often influence height by less than one millimetre.
Scientists, including those from Queen Mary University of London (QMUL) and the University of Exeter in the UK, found new DNA changes that led to differences in height of up to two cm - over 10 times the average effect of previously discovered gene variants.
"The new genetic variants we found are rare in the population but their large effects on human height have revealed important new insights into human skeletal growth," said Professor Panos Deloukas from QMUL. "The identified genes will be helpful in predicting a person's risk of developing certain growth disorders," said Deloukas.
"There is also the hope that we may one day be able to use this knowledge to develop a precision medicine approach for dealing with growth disorders," he said. "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 R Wood, from University of Exeter.
"How the body grows from a 40-50 cm baby into a perfectly proportioned adult three to four times the size, and how this occurs such that some of us end up being over half a metre taller than others, is a fascinating but poorly understood
aspect of biology," said Wood. Many of the new DNA changes are located in genes implicated in growth or bone biology, but many also highlight new biological processes that modulate height in humans.
The researchers looked at two of the changes found in a gene called STC2. Only one person in 1,000 carries one of these genetic variants, but those who do are 1-2 cm taller. Further study suggested that these variants modulate height by interfering with the availability of growth factors in the blood.
Studying STC2 may therefore yield new insights into therapeutic strategies to treat growth failure, which affects three to five per cent of all children. "We used adult height as a simple observable physical trait to understand how information in our DNA can explain how we are all different," said Guillaume Lettre at Universite de Montreal in Canada. The study was published in the journal Nature.
