Like all aspects of the development of the human body, genetics dictate each individual’s height. Last year a team of researchers identified the initial common gene that influences height. That same team has now identified 20 additional genetic regions that can collectively influence height differences of almost 2.5 inches.

According to the research team, 90% of the variation in height is a result of genetics. This is different than weight issues, such as obesity, which is a result of a mixture of environmental and genetic causes. That first height gene discovered last year is only responsible for less than a quarter of an inch.

The team from the Peninsula Medical School in Exeter and the University of Oxford studied DNA samples from over 30,000 people. These samples were obtained from the Wellcome Trust Case Control Consortium, the Cambridge Genetics of Energy Metabolism consortium and the CoLaus Study in Switzerland. From these samples the researchers discovered 20 loci, or regions of genetic code, which have an impact on the height.

One of these regions has been identified as an important factor in the development of osteoarthritis. This particular locus is thought to be involved in the growth of cartilage.

“There may be more than a hundred genes which affect our height, many of which will work in surprising or unpredictable ways,” according to Dr. Mike Weedon, lead author on the paper. “The challenge now for us is to understand how they influence growth in the body. This could open up new avenues for treating a range of diseases.”