title: Methemoglobinemia in a young man.
abstract: In patients who have cyanosis and dyspnea that are unrelated to a cardiopulmonary cause, 1 rare possible diagnosis is methemoglobinemia. This condition is generally asymptomatic, even when the methemoglobin level is as high as 40% of the total hemoglobin value. In the patient described herein, extensive pulmonologic and cardiologic investigations failed to yield the correct diagnosis, which was finally made on the basis of physical findings and arterial blood-gas analysis. Later, a DNA analysis, reported separately by others, showed that the patient's methemoglobinemia was caused by a novel mutation of the cytochrome b5 reductase gene.
authors.affiliation: Department of Adult Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Baylor College of Medicine; Houston, Texas 77030-2304, USA.
authors.forename: Yasmin S
authors.initials: YS
authors.lastname: Hamirani
authors.forename: Wayne
authors.initials: W
authors.lastname: Franklin
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Grifka
authors.forename: Raymond F
authors.initials: RF
authors.lastname: Stainback
mesh_terms: D000328:Adult; D003490:Cyanosis / Q000209:etiology; D042966:Cytochrome-B(5) Reductase / Q000235:genetics; D006801:Humans; D008297:Male; D008708:Methemoglobinemia / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D009154:Mutation; D010092:Oximetry
chemical_list: D042966:Cytochrome-B(5) Reductase