Neonatal Cyanosis Due to a Novel Fetal Hemoglobin: Hb F-Circleville [Gγ63(E7)His→Leu, CAT>CTT]

Neonatal cyanosis can result from a multitude of acquired and inherited causes. Cyanosis resulting from fetal M hemoglobin (Hb) variants is very rare. Only two Gγ variants causing methemoglobinemia and cyanosis in the newborn have been reported to date. Here we describe a novel fetal Hb variant, Hb F-Circleville [Gγ63(E7)His→Leu], associated with methemoglobinemia and cyanosis in the newborn. The patient's sister also had neonatal cyanosis at birth.