Described herein is the finding that patients with Sjögrens syndrome exhibit a statistically significant increase in expression of BMP6 in the salivary gland, relative to healthy control subjects. Also described herein is the finding that overexpression of BMP6 in the salivary glands of mice results in an increase in electrical potential across the salivary gland. Thus, provided herein are methods of diagnosing a subject as having Sjögrens syndrome, or at risk for developing Sjögrens syndrome, by measuring the level of BMP6 expression in a salivary gland of a subject, measuring electrical potential in a salivary gland of a subject, or both. Also provided herein are methods of treating a subject with Sjögrens syndrome by administering an agent that inhibits expression of BMP6 expression or activity. Also described herein is the use of XIST and MECP2 as diagnostic and therapeutic targets for male Sjögrens syndrome patients.