Hemolytic anemia associated with myotonic muscular dystrophy

Hemolytic anemia developed in a male who had been diagnosed as having myotonic muscular dystrophy (MMD). His red cell life-span examined by 51Cr-labeling method was shortened (T 1/2 = 6.5 days). Specific abnormalities of red cells were not found other than increased osmotic resistance, increased intracellular sodium, and decreased intracellular potassium of red cells. A clinical review of 18 other patients with MMD did not reveal any signs of hemolysis. It may be suggested that the underlying red cell membrane defects due to MMD contributed to this rare association with hemolysis.