Hereditary Abnormal Transcobalamin II Previously Diagnosed as Congenital Dihydrofolate Reductase Deficiency

Abstract

To the Editor: In 1976 Tauro et al.¹ described two children in whom megaloblastic anemia occurred at birth and four weeks, respectively. The authors ascribed the condition to congenital deficiency of dihydrofolate reductase. The children were treated with folinic acid, and both had excellent hematologic responses. In 1978 we reinvestigated Case 2 of that report, because of the development of mental retardation and severe neuropathy after two years of treatment with folinic acid. The clinical details are described elsewhere.² The blood count showed the following values: hemoglobin, 11.0 g per deciliter, packed cell volume, 34.5 per cent, red cells, 4.63x10 . . .