A number of genes associated with lupus have been discovered by scientists, with one in particular thought to be a "key player" in the risk of developing the autoimmune disease. Researchers analysed over 17,000 human DNA samples from people living in South Korea, China, Malaysia and Japan, finding 10 specific genes linked to lupus.
The team, led by the Oklahoma Medical Research Foundation in the US, said the discovery marks a "significant advance" in our understanding of lupus genes. Furthermore, they say these findings will help us better understand what triggers it and pave the way for more targeted treatments.
Lupus is disease where the body's immune system becomes unbalanced, leading it to attack its own tissues. It can affect many different parts of the body, including the skin, kidneys, heart, lungs and joints. It is complicated and, at present, poorly understood – but is known to predominantly appear in women and is more common in people of African, Caribbean and Asian origin.
Swapan Nath, lead author of the latest study published in Nature Genetics, said: "We know lupus has a strong genetic basis, but in order to better treat the disease we have to identify those genes. Large-scale studies of this magnitude are becoming the gold standard for locating genes associated with autoimmune diseases like lupus."
Of the 17,000 samples collected, 4,500 had confirmed cases of lupus. Along with the 20 already identified genes, they found 10 more – one of which seems particularly significant. GTF21 showed a high likelihood of being involved in the development of the disease. GTF21 has previously been linked to the rare neurodevelopmental disorder Williams-Beuren syndrome and the autoimmune disorder Sjögren's syndrome.
"GTF2I seems to be one of the key players in lupus susceptibility," said Nath. "Its genetic effect appears to be higher than previously known lupus genes discovered from Asians, and we surmise that it now may be the predominant gene involved in lupus."
Researchers say they can now try to work out where defects occur and whether mutations contribute to the onset of lupus – understanding how and where defects arise will help scientists develop more effective therapies that can target specific genes. "We are a long way from that point, but huge collaborative efforts like this help to get things going," Nath said.
Judith James, director of OMRF's Autoimmune Disease Institute, said: "These findings mark a significant advance in our knowledge base for lupus genes. For every gene we identify, it brings us closer to uncovering the trigger for this puzzling disease. It's good news for researchers and patients alike."