Scientists have identified a cluster of key genes which together can make a height difference of up to 6 centimeters, according to a study published in Sunday's Nature Genetics.

The study by British scientists entailed sifting through samples from more than 30,000 people of European descent to look for common variations in the genetic code that help determine height.

They identified 20 regions of the genome, also known as loci, which provide insights into how the body develops normally.

"The number and variety of genetic regions that we have found show that height is not just caused by a few genes operating in the long bones," said Tim Frayling of the Peninsula medical school, Exeter, who led the study.

"Instead, our research implicates genes that could shed light on a whole range of important biological processes. By identifying which genes affect normal growth, we can begin to understand the processes that lead to abnormal growth -- not just height disorders but also tumor growth, for example."

Unlike other body size characteristics such as obesity, 90 percent of normal variation in human height can be attributed to one's DNA heritage rather than nutrition.

The 20 loci account for roughly three percent of this 90 percent. Last September, the same team found a genetic variant that accounted for another 0.3 percent.