Exon sequencing of the alpha-2-globin gene for the differential diagnosis of central cyanosis in newborns: a case report

BMC Pediatrics

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[1] 0000 0004 0470 4224, grid.411947.e, Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea;0000 0004 0470 4224, grid.411947.e, Catholic Genetic Laboratory Center, College of Medicine, The Catholic University of Korea, Seoul, South Korea;0000 0004 0470 4224, grid.411947.e, Department of Pediatrics, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, 93-6 Ji-dong, 16247, Paldal-gu Suwon-si, Gyeonggi-do, South Korea;

关键词: Hemoglobin M;    Cyanosis;    Newborn;    Methemoglobin;   

DOI  :  10.1186/s12887-019-1601-9

来源: publisher

【 摘 要 】

BackgroundCyanosis is usually associated with serious conditions requiring urgent treatment in the neonatal intensive care unit (NICU). Hemoglobin M (Hb M) disease is one type of congenital methemoglobinemia characterized by cyanosis. Among these variants, α-globin chain mutations such as Hb M Boston present cyanosis from birth while other variants usually manifest later in life.Case presentationWe report a case of a male newborn with cyanosis apparent since birth. Surprisingly, his respiratory and hemodynamic status including normal arterial blood oxygen saturation was stable, but oxygen saturation on pulse oximetry did not increase after 100% supplemental oxygen was started. In addition to routine pulmonary and cardiologic evaluation, further evaluation for dyshemoglobin was conducted; α2-globin gene sequencing showed a single-point variant causing Hb M Boston. Methemoglobin (MetHb) level estimated by co-oximetry was normal. After a 14-day stay in the NICU, the patient remained respiratory and hemodynamically stable without supplemental oxygen except for cyanosis.ConclusionsHb M disease is a benign disease and does not require any treatment whereas acquired methemoglobinemia is a potentially fatal condition. Neonatologists should be aware that low oxygenation status on pulse oximetry in the face of normal arterial blood saturation values might indicate the possibility of Hb M disease in early neonatal cyanosis, irrespective of MetHb value.

【 授权许可】

CC BY