PPOX
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Gene summaries condense public reference material; disease links and population data change as databases are updated. Clinical decisions belong with your care team.
protoporphyrinogen oxidase
Normal Function
Health Conditions Related to Genetic Changes
Porphyria
More than 130 mutations in the PPOX gene have been identified in people with a form of porphyria called variegate porphyria. A particular PPOX gene mutation is found in about 95 percent of South African families with this form of the disorder. The mutation changes a single protein building block (amino acid) in protoporphyrinogen oxidase, replacing the amino acid arginine with the amino acid tryptophan at position 59 (written as Arg59Trp or R59W).
Mutations in the PPOX gene reduce the activity of protoporphyrinogen oxidase, allowing compounds called porphyrin precursors to build up in the body. These compounds are formed during the normal process of heme production, but reduced activity of protoporphyrinogen oxidase allows them to accumulate to toxic levels. Nongenetic factors such as certain drugs, alcohol, dieting, as well as other genetic factors that have not been identified, also contribute to the characteristic features of variegate porphyria.
More About This Health ConditionRelated Conditions
Porphyria
Health Conditions Related to Genetic Changes
More than 130 mutations in the PPOX gene have been identified in people with a form of porphyria called variegate porphyria. A particular PPOX gene mutation is found in about 95 percent of South African families with this form of the disorder. The mutation changes a single protein building block (amino acid) in protoporphyrinogen oxidase, replacing the amino acid arginine with the amino acid tryptophan at position 59 (written as Arg59Trp or R59W).
Mutations in the PPOX gene reduce the activity of protoporphyrinogen oxidase, allowing compounds called porphyrin precursors to build up in the body. These compounds are formed during the normal process of heme production, but reduced activity of protoporphyrinogen oxidase allows them to accumulate to toxic levels. Nongenetic factors such as certain drugs, alcohol, dieting, as well as other genetic factors that have not been identified, also contribute to the characteristic features of variegate porphyria.