Related Experiment Video
Updated: Jul 5, 2026
06:45
Use of Electron Paramagnetic Resonance in Biological Samples at Ambient Temperature and 77 K
Published on: January 11, 2019
Methemoglobinemia in a young man
Yasmin S Hamirani1, Wayne Franklin, Ronald G Grifka
1Department of Adult Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Baylor College of Medicine; Houston, Texas 77030-2304, USA.
Texas Heart Institute Journal
|April 23, 2008
Summary
Methemoglobinemia is a rare cause of cyanosis and dyspnea. A novel mutation in the cytochrome b5 reductase gene was identified as the cause in a patient with unexplained symptoms.
Area of Science:
- Biochemistry
- Genetics
- Internal Medicine
Background:
- Methemoglobinemia is a rare condition causing cyanosis and dyspnea.
- It is often asymptomatic, even with high methemoglobin levels.
Observation:
- Pulmonologic and cardiologic evaluations did not diagnose the patient's symptoms.
- Diagnosis was established through physical findings and arterial blood-gas analysis.
Findings:
- A novel mutation in the cytochrome b5 reductase gene was identified.
- This genetic mutation caused the patient's methemoglobinemia.
Implications:
- Highlights the importance of considering methemoglobinemia in unexplained cyanosis and dyspnea.
- Identifies a new genetic cause for methemoglobinemia, advancing understanding of the condition.
Related Concept Videos
01:23Hypoxia
Hypoxia is a medical condition characterized by an inadequate oxygen supply to body tissues. It typically manifests as a bluish discoloration of the skin and mucosae, especially in fair-skinned individuals, when hemoglobin (Hb) saturation drops below 75%.
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
Types of Hypoxia
There are four primary types of hypoxia, each resulting from a different cause:
1. Anemic hypoxia: This type occurs due to insufficient oxygen delivery caused by a lack of red blood cells (RBCs) or RBCs with abnormal or...
01:26Rocky Mountain Spotted Fever
Rocky Mountain Spotted Fever (RMSF) is a severe tick-borne illness caused by Rickettsia rickettsii, a Gram-negative, coccobacillary bacterium. This pathogen is an obligate intracellular parasite, requiring a host cell for replication. Transmission occurs through the bite of an infected tick. In the United States, the most important vectors are Dermacentor variabilis (American dog tick) and Dermacentor andersoni (Rocky Mountain wood tick), though other tick species may also serve as vectors.
01:20Inborn Errors of Metabolism
Phenylketonuria (PKU) is a protein metabolism disorder characterized by high blood levels of the amino acid phenylalanine. This results from a mutation in the gene responsible for phenylalanine hydroxylase, an enzyme that converts phenylalanine into tyrosine. When this enzyme is deficient, phenylalanine builds up in the blood, leading to symptoms such as vomiting, rashes, seizures, growth deficiency, and severe mental retardation. An early diagnosis and a diet restricting phenylalanine intake...