Noonan syndrome associated with systemic lupus erythematosus.

Noonan syndrome (NS) is a developmental disorder characterised mainly by cardiac defects and craniofacial dysmorphia. An association between NS and some autoimmune diseases, such as thyroiditis and systemic lupus erythematosus (SLE), has been suggested. We report the case of a 28-year-old man with a diagnosis of NS and autoimmune hypothyroidism who developed symptoms and immunologic features of SLE.