What factors determine height? Major study helps researchers gain better understanding

A woman looks up at a taller man in this file photo. (Marco Brockmann/shutterstock.com)

Parents may not be completely to blame for how high their kids measure up to their peers, a new study finds.

While the relationship of height and genetics is one that has typically been misunderstood, a recent study published in Nature has moved the research forward through its findings.

The genome-wide association study examined the DNA of five million people from across 281 contributing studies, the largest ever study of this kind, and found that more than 12,000 genetic variants can account for height differences amongst people.

The majority of those examined in the study were of European ancestry, with just over 1 million of the study’s participants being of non-European ancestry, including African, East Asian, Hispanic or South Asian.

The DNA which makes up our bodies holds the blueprint for all the proteins of the body, which are the molecules that do the work in the cell, David R. Ross, professor emeritus of the faculty of biology at the University of Waterloo told CTVNews.ca. “They cause us to be tall or short, for example, so the DNA is really important.”

And while taller parents tend to have taller children, and shorter parents have shorter children, the researchers found that this factor may not always be a perfect indicator for height.

In fact, the genetic variants associated with one’s height are concentrated in regions covering over 20 per cent of the genome.

The genome is the complete set of genes or genetic material present in a cell or organism.

In the human genome, there are about three billion nucleotides - which are the basic building block of nucleic acids (RNA and DNA), nucelid acids being the naturally occurring chemical compounds that serve as the primary information-carrying molecules in cells.

The researchers state that the findings are particularly beneficial as they can help doctors identify people who aren’t able to reach the height they have been predicted to meet as an adult. They then could help to identify hidden diseases or conditions that may stunt growth, or other health impacts.

“Any trait, in this case it’s height, could be susceptible to disease,” says Ross. “It's tempting to think that someone may have a gene that causes cancer, for example, but it's always a lot more complicated than that. It's usually a whole bunch of genes together that cause a particular trait. So that's why it was so important for them to look at five million people.”

Further, the research findings also lay out the possibility of genome-wide studies to identify a disease's biology, followed by its hereditary components, which could be integral to solving global health challenges.

The study states that further research would be needed to achieve the same understanding in ancestries other than populations of European ancestry.