INCREASED IDDM SUSCEPTIBILITY BY HLA-DRA IN A PEDIGREE WITH PROLONGED QT SYNDROME:

Prolonged QT(Romano-Ward) syndrome, characterized by prolonged QT interval in electrocardiogram and may result in fatal arrhythmia, is inherited as as autosomal dominant trait. It has recently been disclosed that the gene responsible for the syndrome (c-Harvey-ras 1) is located on chromosome Hp 15.5 and very close to a gene for insulin and IGF-2. [Case] A Japanese pedigree with the syndrome for subsequent three generations was reffered to our hospital for the treatment of overt diabetes mellitus in a 13-year-old boy. He had hyperglyeomia (739 mg/dl), ketosis and serious weight loss, insulin administration was then introduced. ICA and ICSA were negative. The boy, his father and his grandfather had definitly prolonged QT interval and clinical manifestations such as syncope. Hyperglyeemia was seen only in the diabetic boy. HLA-DR4 was detected only in the boy with DH (DR4, DR9). His father had DR2 and DR9 (mother not tested).