Monozygotic twins with primary Sjögren's syndrome.

Sjögren's syndrome (SS) is a chronic autoimmune disease mainly characterized by dry mouth and dry eyes due to an inflammatory process in the exocrine glands. We describe a pair of Caucasian monozygotic twin sisters and their mother, all having primary SS. The twins had very similar clinical presentation and almost identical serological data, and histological examination of lower labial salivary glands gave a focus score of 3 in both twins. We also present their family medical history, which shows aggregation of immunological disorders among family members, although the twins and their mother were the only individuals with primary SS.