Hemoglobin M Disease as a Cause of Cyanosis in a Newborn.

Methemoglobinemia, including the inherited or congenital form, is a known but infrequent cause of neonatal cyanosis. We present the case of a newborn patient with neonatal cyanosis, who was diagnosed with F-M-Osaka methemoglobinemia, and an up-to-date literature review of the disease.