Autoimmunity in Down’s Syndrome: Another Possible Mechanism of Moyamoya Disease

To the Editor: The presence of Down’s syndrome (DS) associated with moyamoya disease has been increasingly noted in the last years. Several reports suggest that the incidence of moyamoya disease is higher in children with DS than in other children. Since 1977, when this association was described for the first time, more than twenty cases have been reported.1 2 3 However, the reason of this association is unknown. Furthermore, DS is associated with autoimmune disorders.4 We describe a child with trisomy 21 affected by moyamoya and Graves’ disease, associated with anti-thyroid microsome antibodies and antiphospholipid antibodies (aPL). This patient was included in the prospective study of stroke in young adults in Cantabria, Spain.5 6 A 21-year-old man was admitted to the hospital on May 27, 1986. Thirteen days before, his mother noticed a sudden muscle weakness in his left arm; 3 days later she also noted that he had difficulty in walking because of a weakness in his left leg. The patient was the eighth pregnancy of a mother who was 39 years of age at the time of delivery. When he …