LONG QT SYNDROME WITH INSULIN-DEPENDENT DIABETES-MELLITUS - CONTIGUOUS GENE SYNDROME ON CHROMOSOME-11P

Long QT syndrome (Romano-Ward syndrome) and insulin-dependent diabetes mellitus (IDDM) have been documented as being linked with gene(s) on chromosome 11p although concurrence of the two disorders has not been reported. Our case is a 13-year-old boy with Romano-Ward syndrome acco mpanied by IDDM. The long QT syndrome seemed to be transmitted in an a utosomal-dominant mode because the Q-T intervals of his father and pat ernal grandfather were longer than normal. There was no family member with an abnormally high level of blood glucose except the patient. The human leucocyte antigen (HLA) haplotypes of the patient and the fathe r were DR4/DR9 and DR2/DR9, respectively. This study suggests that in our patient IDDM, as well as Romano-Ward syndrome, is linked with chro mosome 11p in the presence of HLA-DR4. The results support the previou s study that chromosome 11p encodes a gene implicated in HLA-DR4-depen dent diabetes susceptibility.