Early onset of type I diabetes mellitus, Hashimoto's thyroiditis and celiac disease in a 7-yr-old boy with Down's syndrome.

Patients with Down's syndrome are at higher risk for developing autoimmune diseases than those of the general population. Autoimmune diseases like Hashimoto's thyroiditis, Graves' disease, diabetes mellitus type I, celiac disease, autoimmune chronic active hepatitis, alopecia, vitiligo and hypoparathyroidism are recognized associations with Down's syndrome. We describe the case of a very young boy with Down's syndrome who was diagnosed with diabetes mellitus type I, Hashimoto's thyroiditis and celiac disease before 8 yr of age. Unspecific symptoms like weight loss, unstable blood sugar with high amplitudes, behavioural problems and dry skin were suspicious for other endocrine disorders or celiac disease in our case. The boy was showing the typical human leukocyte antigen profile for these autoimmune diseases. The prevalence of these autoimmune diseases is higher in Down's syndrome than in general population. Therefore, we advice to follow children with Down's syndrome who develop more than two autoimmune diseases very carefully.