Why Are Some People Taller Than Others? Scientists Finally Have An Answer

Researchers analysing more than 700,000 people's DNA find 83 genetic changes accounting for height difference
Scientists have finally discovered why some people are taller than others.

They found 83 genetic variants affect height after analysing the DNA of 700,000 people.
The genetic changes account for height differences of up to two centimetres.

Previously identified common variants linked to tallness are much weaker, each of them typically adjusting height by less than a millimetre.

The new international study, published in the journal Nature, is the largest investigation to date of genetic factors associated with height.

A number of the variants - alterations in the chemical sequences making up DNA - flagged up previously unknown biological pathways involved in skeletal growth.
One of the signposted genes, STC2, makes a protein that acts as a brake on human height. Scientists believe it could provide a target for new treatments for growth problems in children.

British researcher Professor Panos Deloukas, from Queen Mary, University of London, who co-led the study, said: “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. The identified genes will be helpful in predicting a person’s risk of developing certain growth disorders.

“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.”

Colleague and co-author Dr Andrew Wood, from the University of Exeter, added: “Our latest discovery means that we can now explain over a quarter of the heritable factors involved in influencing a person’s height.

“How the body grows from a 40-50cm 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.”

In 2014 scientists involved in the research project, known as Giant (Genetic Investigation of Anthropometric Traits), identified nearly 700 height variants after analysing the complete DNA of 250,000 people.

However such genome-wide association studies that cast a net over the whole of a person’s genetic code are not good at capturing uncommon genetic variants having large effects.

For the new study, the researchers used a different method to test for a catalogue of nearly 200,000 less common genetic variants known to alter the function of protein-coding genes.
Data from a total of 711,428 people highlighted 83 uncommon variants that exerted a strong influence on adult height. Of these, 51 were “low frequency” variants found in less than 5% of the population, and 32 were rare variants found in less than 0.5%.

Professor Guillaume Lettre, one of the chief investigators from the University of Montreal in Canada, said: “Of these 83 genetic variations, some influence adult height by more than two centimetres, which is enormous.

“The genes affected by these genetic variations modulate, among other things, bone and cartilage development and growth hormone production and activation.”



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