M202 PERSISTENT MTHFD1-DEFICIENT SEVERE COMBINED IMMUNODEFICIENCY DESPITE FOLINIC ACID SUPPLEMENTATION; HEMATOPOIETIC ALLOGENEIC TRANSPLANTATION REQUIRED

Abstract

Methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) deficiency is a rare cause of severe combined immunodeficiency (SCID); it presents with megaloblastic anemia and sometimes atypical hemolytic uremic syndrome. In reports of four prior cases, treatment with folic/folinic acid corrected T-cell deficiency and reversed SCID.