IN RECENT years there has been increased interest in familial and acquired anemias associated with erythrocytic inclusion bodies.1 Simultaneously, the hereditary transmission of certain hematological disorders has received attention.2 The purpose of this report is to present an investigation which has led us to propose that there exists a type of hemolytic anemia secondary to a hereditary defect in hemoglobin synthesis and associated with rubricytic inclusion bodies. It is our opinion that mechanisms heretofore not generally recognized have been demonstrated in this study. BACKGROUND A. Familial Anemias. —The familial nature of certain anemias is well known. Familial hemolytic anemia (familial spherocytosis) is transmitted as a mendelian dominant trait, and the genetics of hereditary leptocytosis (thalassemia; Mediterranean disease) and sickle cell disease have been clarified recently. Valentine and Neel2e postulated that thalassemia major may be due to homozygosity for a factor which when