Future directions in genetic for autoimmune diseases.

Autoimmune diseases affect cumulatively 5-10% of the general population and are multifactorial in their pathogenesis, with both inherited and environmental components. Although our knowledge of their pathogenesis has become more refined, diagnosis more accurate, and therapy more effective, the reasons for their development and the female preponderance of these diseases are still unknown. One of the most intriguing hypothesis to explain the female preponderance is related to sex chromosomes, as women affected by autoimmune diseases have a higher rate of circulating cells with a single X chromosome. In addition, a number of evidences suggest a role of X chromosome gene dosage in autoimmunity. Based on these findings, sex chromosome defects might be the common trait of the susceptibility to autoimmune diseases.