Sickle cell trait/hereditary persistence of fetal hemoglobin trait. Misdiagnosis as sickle cell anemia by newborn screening.

A black female infant, reported as a result of mandatory newborn screening to have sickle cell anemia, was found at 8 months of age to have instead the entirely benign disorder sickle cell trait/hereditary persistence of fetal hemoglobin trait. The finding of hemoglobin S without Hb A does not suffice for the diagnosis of homozygous Hb S. Screening programs that diagnose sickle cell aneimia without first demonstrating sickle hemoglobin in both parents will consistently misdiagnose several more benign hemoglobin states as sickle cell anemia.