Down syndrome presenting with multiple sclerosis, thyroid dysfunction, and diabetes mellitus. Multiple autoimmune disorders in a genetic disorder.

Down syndrome (DS) is one of the most common survivable chromosomal disorders, and is well known to be associated with multiple autoimmune diseases. Multiple sclerosis (MS) is a chronic inflammatory autoimmune demyelinating disease of the central nervous system. An association of DS and other autoimmune disease has been previously reported, and we report one case of DS in coexistence with MS, diabetes mellitus, and thyroid diseases. We suggest that MS, such as other autoimmune diseases, is prevalent in DS patients.