HbM methaemoglobinaemia as a rare case of early neonatal benign cyanosis.
Early neonatal central cyanosis that is unrelated to cardiopulmonary causes, alerts clinicians to possibility of methaemoglobinaemia. Congenital methaemoglobinaemia due to haemoglobin M is an autosomal dominant disorder characterised by lifelong cyanosis. We report a case presentation and review of diagnostic pitfalls of a newborn who presented with central cyanosis; investigations revealed a low methaemoglobin reductase (2.2 IU/g Hb), with normal maternal levels (9.1 IU/g Hb). Therefore, haemoglobinopathy investigations were completed on the mother and her baby, which showed an α-globin variant in both. The maternal α2 globin gene sequencing showed heterozygosity for haemoglobin M Boston (α58 His → Tyr).
Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.
Mohamed Sabry
MS
Elboraee
Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada.
Gwen
http://orcid.org/0000-0002-2071-388X
G
Clarke
Department of Pediatrics, Division of Hematology, Oncology and Palliative Care, University of Alberta, Edmonton, Alberta, Canada.
Mark J
http://orcid.org/0000-0002-7795-1862
MJ
Belletrutti
Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.
Sandra
http://orcid.org/0000-0002-7512-8485
S
Escoredo
D003490:Cyanosis / Q000209:etiology*; D042966:Cytochrome-B(5) Reductase / Q000097:blood / Q000172:deficiency; D006449:Hemoglobin M / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008708:Methemoglobinemia / Q000175:diagnosis* / Q000235:genetics*
C027541:hemoglobin M Boston; D006449:Hemoglobin M; D042966:Cytochrome-B(5) Reductase