What factors affect teenage height growth

What affects body size

It's already a reality in the film. All a nurse needs to predict the development of a newborn is a drop of blood. Then she knows which diseases threaten in the course of life: 60 percent probability for neurological disorders, 42 percent for depression, 99 percent for heart disease and a life expectancy of 30.2 years. That is the prognosis for little Anton in the film "Gattaca". A study in the current issue of the journal “Nature” shows that some things can already be predicted from genes today - for example, the future height.

Big parents, big kids. Little parents, little kids. Is the connection that simple? On the whole, the scientists suspect, yes. 80 percent of the body size is actually determined by the genome, although it is not a single gene, but a complex interplay of different genetic information that is responsible for this. However, 20 percent of human growth is determined by diet and other environmental factors.

So far, the researchers have only been able to explain a small part of the size differences genetically. The international “Giant” consortium has dramatically increased knowledge of this complicated genetic interplay. Scientists from 203 institutions in Europe and the US collaborated for the analysis.

Genes that indirectly affect height growth

They systematically examined the genes and height of around 185,000 adults. In doing so, they discovered thousands of genetic markers or SNPs (read: "Snips", an abbreviation for Single Nucleotide Polymorphism) at around 180 characteristic gene locations. They all play a part in the multi-layered concert of size genes. The 180 places that are jointly responsible for body growth are often close to disease genes, for example for abnormal bone growth or arthritis and diabetes.

The authors of the scientific study suspect that these genes indirectly influence height growth. “This is the first time we've seen evidence of a link between growth and disease,” says Fernando Rivadeneira of the Erasmus Medical Center in the Netherlands. But that is not the only thing that should be examined more closely, the authors believe. The gene locations beyond the growth genes known today could also reveal biological mechanisms that make one dwarf and another giant. The researchers now want to start an even larger study.

They want to study 500,000 adults in order to identify hundreds more locations in their genome that are related to the growth in height. Then, they estimate, 20 percent of the size puzzle would be completed. There seems to be a simple rule of thumb as to how tall a person is. Add six centimeters to the mean of the parents' height for boys - and subtract six centimeters for girls.