A group of scientists has found a gene suspected of causing osteoarthritis, the most common form of human arthritis, the science magazine Nature Genetics reported Sunday.

"We identified asporin as a susceptibility gene for osteoarthritis in the Japanese population," a research group led by Shiro Ikegawa, of the Laboratory for Bone and Joint Disease of the RIKEN SNP Research Center, said in a report published by the online edition of Nature Genetics.

"We carried out a case-control association study of asporin in Japanese individuals with osteoarthritis and identified a significant association between asporin and both knee and hip osteoarthritis," it said.

Asporin is an extracellular matrix component in the articular cartilage of individuals with osteoarthritis, according to the group.

This is the first time in which the gene that causes osteoarthritis has been identified. The finding is expected to help develop a drug to treat the disease.

Osteoarthritis is the most common joint disease in humans and a primary cause of decreased mobility in daily life after middle age.

Osteoarthritis, the most common joint disease in humans and a primary cause of decreased mobility in daily life after middle age, affects more than 5 percent of adults worldwide and more than 7 million people in Japan alone, the group said.