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GTR Home > Conditions/Phenotypes > Deficiency of cytochrome-b5 reductase

Deficiency of cytochrome-b5 reductase

Synonyms
Diaphorase deficiency; METHEMOGLOBINEMIA, CONGENITAL, AUTOSOMAL RECESSIVE; Methemoglobinemia Due to Deficiency of Methemoglobin Reductase; NADH cytochrome B5 reductase deficiency; NADH diaphorase deficiency; NADH methemoglobin reductase deficiency

Summary

Methemoglobinemia due to NADH-cytochrome b5 reductase deficiency is an autosomal recessive disorder characterized clinically by decreased oxygen carrying capacity of the blood, with resultant cyanosis and hypoxia (review by Percy and Lappin, 2008). There are 2 types of methemoglobin reductase deficiency. In type I, the defect affects the soluble form of the enzyme, is restricted to red blood cells, and causes well-tolerated methemoglobinemia. In type II, the defect affects both the soluble and microsomal forms of the enzyme and is thus generalized, affecting red cells, leukocytes, and all body tissues. Type II methemoglobinemia is associated with mental deficiency and other neurologic symptoms. The neurologic symptoms may be related to the major role played by the cytochrome b5 system in the desaturation of fatty acids (Vives-Corrons et al., 1978; Kaplan et al., 1979). [from OMIM]

Available tests

22 tests are in the database for this condition.

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Clinical tests (22 available)

Molecular Genetics Tests

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  • Also known as: B5R, DIA1, CYB5R3
    Summary: cytochrome b5 reductase 3

Clinical features

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Imported from Human Phenotype Ontology (HPO)

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