Co-Existence of Insulin Dependent Diabetes and Graves' Disease in a Patient with Down Syndrome/Down Sendromlu Bir Hastada Insuline Bagimli Diyabet Ve Graves Hastaligi Birlikteligi (Case Report/Olgu Sunumu) (Case Study‪)‬

Introduction Down's syndrome is the most common genetic disorder leading to mental retardation and can easily be diagnosed at birth with the typical phenotypic appearance. The incidence is 1 in 700 live births (1). Approximately 300 thousand people are affected in the United States. Individuals with Down's syndrome have six fold increased risk of developing insulin dependent diabetes and four fold increased risk of developing autoimmune thyroid disease (2-4). Several autoimmune diseases are also commonly seen in Down's syndrome other than autoimmune diabetes and thyroid disease such as alopecia, vitiligo, celiac disease, chronic active hepatitis and hypoparathyroidism (5-8). The exact mechanism of susceptibility to autoimmune diseases is not clear in Down's syndrome. Herein, we describe a patient with Down's syndrome who presented with autoimmune diabetes and co-existing Graves disease. The possible mechanisms leading to autoimmune diseases in Down's syndrome are discussed.