Icelandic genetic mutation triples risk of autoimmune thyroid disease, reveals study

An Icelandic genetic mutation that triples the risk of autoimmune thyroid disease has been discovered. About 0.13% of individuals, or roughly 500 Icelanders, carry this altered gene.

Five percent of people develop autoimmune diseases at some point in their lives. Scientists from Icelandic Genetic Analysis conducted extensive research to determine which genetic variants contribute to autoimmune thyroid disease, the most common autoimmune disease, which can result in an underactive or overactive thyroid gland.

The risk gene, LAG3, was identified by Sædís Sævarsdóttir, a scientist at Icelandic Genetic Analysis and one of the researchers. She states that two rare mutations were revealed in the research. “One that is only found in Iceland and another that is only found in Finland – which pointed us towards a specific risk gene called LAG3.”

This Iceland-specific mutation increases the chances of vitiligo fivefold and more than triples the chances of autoimmune thyroid disease. Vitiligo is a long-term skin condition characterized by patches of the skin losing their pigment.

Sævarsdóttir explains that only about 0.13% of individuals carry these mutations, equating to about 500 Icelanders. She assures that this mutation will not require screening in the future as it has not been linked to increased risk of death.

The effects of this genetic variant are similar to the effects of drugs that stimulate the immune system against cancer. Both vitiligo and an underactive thyroid could be potential side effects of these drugs because they release immune pathways, and the immune system starts attacking its own tissues – just as autoimmune diseases do.