It is typically believed that Lupus is influenced by multiple genes. Lupus is usually influenced by gene polymorphisms, 30 of which have now been linked with the disorder. Some of these polymorphisms have been linked very tentatively however, as the role that they play or the degree to which they influence the disease is unknown. Other genes that are commonly thought to be associated with Lupus are those in the Human leukocyte antigen (HLA) family, which are largely related to healthy functioning of the immune system. There have been several cases where a single gene influence appears to be present, but this is rare. When a single gene deficiency does cause Lupus, it is usually attributed to the genes C1, C2, or C4. The influence of sex chromosomes
