A mutation in the TLR7 (Toll Like Receptor 7) gene is being studied as one of the causes of Lupus. It is monogenic cause, which means that if you have the mutation in the TLR7 gene, it is highly likely to cause Lupus. This was studied in mice using CRISPR to introduce the mutated TLR7 gene into mice and it was found that all of the mice developed Lupus. Of course, human studies have identified Lupus patients who have the TLR7 mutation as well. Though this mutation is rare, signs of overactivity in TLR7 pathway can be found in many patients. See this article https://www.crick.ac.uk/research/publications/tlr7-gain-of-function-genetic-variation-causes-human-lupus
The mutation results in the TLR7 protein binding to guanosine more easily. This triggers the immune system to become more sensitive causing the immune system to attack healthy tissue.
Carola Vinuesa is part of the Francis Crick Institute and studies immunology. You can read about her and see some of the other genetic links she is researching that are related to Lupus and other immune diseases.
https://www.crick.ac.uk/research/find-a-researcher/carola-vinuesa