Protoporphyria, x-linked dominant
HistoryThis section has been translated automatically.
Whatley, 2008
DefinitionThis section has been translated automatically.
Very rare, X-linked dominant inherited porphyria form ( OMIM 300752) with phototoxic skin reactions due to elevated protoporphyrin in erythrocytes and pathologically elevated plasma protoporphyrin in serum. As in erythropoietic protoporphyria, the clinical symptoms are triggered by short-wave visible and long-wave UVA light (window glass offers no protection).
EtiopathogenesisThis section has been translated automatically.
Mutation of the mitochondrial 5-aminolevulinic acid gene (ALAS2 gene), which is located on chromosome Xp11.21 and is expressed exclusively in erythrocytes.
Clinical featuresThis section has been translated automatically.
S. erythropoietic protoporphyria
LaboratoryThis section has been translated automatically.
- Urine: Normal color, protoporphyrin is elevated.
- Faeces: protoporphyrin is elevated, coproporphyrin is elevated.
- Erythrocytes: Orange-red fluorescence in the fluorescence microscope, which disappears after 10-15 seconds.
- Protoporphyrin is elevated in erythrocytes. The peculiarity that distinguishes this form from classical erythropoietic protoporphyria is the predominance of zinc chelated protoporphyrins (in erythropoietic protoporphyria the free fraction clearly predominates).
Complication(s)This section has been translated automatically.
Particularly high risk for the occurrence of fulminant liver failure, which must be considered for all protoporphyrin diseases.
TherapyThis section has been translated automatically.
LiteratureThis section has been translated automatically.
- Frank J et al (2011) Hereditary metabolic diseases with cutaneous manifestation. Dermatologist 62: 98-106
- Whatley Sd et al (2008) C-terminal deletions in the ALAS2-gene lead to gain of function and cause X-linked dominant protoporphyria without anemia or iron overload. At J Hum Genet 83: 408-414