[Diabetes mellitus type I, celiac disease and Imerslund-Gräsbeck syndrome: only an incidental combination of rare diseases?].

We describe the clinical course of a girl with onset of type I diabetes mellitus at the age of 3 years. At the age of 10, coeliac disease and shortly thereafter a vitamin B12 deficiency anemia (Imerslund-Gräsbeck-syndrome) was diagnosed. Her younger sister also suffered from Imerslund-Gräsbeck-syndrome when she was 11 year old. This unusual, so far not described association of rare diseases suggests a common autoimmune etiology.