New gene for rheumatism identified

A genetic variant that can explain the occurrence of a type of rheumatic disorder called SLE has been identified by a research team at Uppsala University, Sweden. The team, led by Associate Professor Marta Alarcón at the Rudbeck Laboratory, is presenting its finding in the latest issue of the scientific journal Nature Genetics.

Nearly 6,000 predominantly young women are victims of systemic lupus erythematosus, SLE. The disease is partly genetic and causes damage to the skin and various organs. The genetic variant in the gene PDCD1 was identified in families with at least two persons suffering from the ailment. Genetic analyses have shown that the part where the gene PDCD1 is located in chromosome 2 is implicated in the disease.

The research team has determined the position of the gene with still greater precision and has sequenced the whole gene. They found several variants, but only one of them repeatedly turned up in the family members with the sickness. In order to make certain that the variant is associated with the ailment, the team studied nearly 2,500 individuals including families in the US. The variant is found in some of the patients and can explain one of the mechanisms behind the development of the disease. The genetic variant in the PDCD1 gene can modify the normal function and expression of the gene, but it is still unclear exactly how.

However, the discovery of this variant makes it possible to move on and examine how various combinations of genes work together to cause the illness. The discovery of this gene variant for SLE is, after a gene variant for Crohn’s disease, the second in the world to be identified for a so-called autoimmune disorder, that is, a disease in which cells from the immune defense produce antibodies to attack the body’s own tissues. It is also one of the few variants to be identified for what are called complex diseases, that is, diseases like heart attacks, high blood pressure, and schizophrenia.

The discovery reported by the research team at Uppsala can improve genetic diagnostics in the future and can contribute to the creation of better therapies for victims of the disorder.