Researchers from the Australian National University have discovered two rare genetic mutations linked to Lupus, the first time a cause of the disease has been determined. Before this study, it was believed the two mutations, BLK and BANK1, had little role in human autoimmunity and related diseases.

Lupus, an autoimmune disorder which affects around half a billion people globally and can cause symptoms including widespread inflammation and tissue damage to skin, organs and blood vessels, was only discovered to be partially genetic in nature in the 1950s.

Recent studies into lupus sufferers found that in most, an unknown factor was driving excessive and sudden production of an immune molecule, even when no virus infection was found. This factor was found to be type 1 interferons, which grew out of control and led to changes in white blood cell development.

This change in development is what BKL and BANK1 are supposed to prevent. In mouse models, the variants also increased the amount of malfunctioning B cells present.

Lupus can also be triggered by hormonal and environmental factors, but one of the biggest risks is still genetic. The chance of a twin sharing the disease with their sibling is around 50%.

Identifying the genes responsible for Lupus should make the disease easier to diagnose, particularly given the difficulty of spotting it due to its symptoms mimic a number of other illnesses. New targets to consider may also help develop new drugs to counter the disease.