Sickle-cell disease not identified by newborn screening because of prior transfusion

Erythrocyte transfusion can impair detection of sickle-cell disease, galact osemia, or biotinidase deficiency with newborn screening. We report on 4 in fants with SCD in whom delayed diagnosis was associated with neonatal trans fusion. In 2 cases, the initial newborn screening showed no hemoglobin S. I n no case was the recommended screening greater than or equal to 120 days f rom the last transfusion obtained. Two children had significant SCD-related morbidity before diagnosis.