Disease relevance of Porphyria, Variegate

• Studies of the enzymes of haem biosynthesis in peripheral blood cells showed a dual enzyme deficiency, with reduced activity of both porphobilinogen deaminase, as seen in acute intermittent porphyria, and protoporphyrinogen oxidase, as seen in variegate porphyria [1].
• The occurrence of hepatic porphyrias--acute intermittent porphyria (AIP) and variegate porphyria (VP)--in Finland has been studied [2].

Psychiatry related information on Porphyria, Variegate

• We report an unusual case of variegate porphyria in a young girl with epilepsy, mental retardation and premature adrenarche [3].

High impact information on Porphyria, Variegate

• A R59W mutation in human protoporphyrinogen oxidase results in decreased enzyme activity and is prevalent in South Africans with variegate porphyria [4].
• Allosteric inhibition of human lymphoblast and purified porphobilinogen deaminase by protoporphyrinogen and coproporphyrinogen. A possible mechanism for the acute attack of variegate porphyria [5].
• Mutation Q127H was detected in exon 3 of the HFE gene together with mutation H63D in an apparently severely affected patient previously shown to carry the protoporphyrinogen oxidase ( PPOX ) gene mutation R59W, which accounts for dominantly inherited variegate porphyria (VP) in >80% of affected South Africans [6].
• We investigated the effects of heme on metabolism of coumarin, debrisoquin, caffeine, and lidocaine in seven female patients with variegate porphyria and in 10 healthy men [7].
• Effects of heme arginate on cytochrome P450-mediated metabolism of drugs in patients with variegate porphyria and in healthy men [7].

Chemical compound and disease context of Porphyria, Variegate

• Rapid normalization of antipyrine oxidation by heme in variegate porphyria [8].
• In the latent stages of acute intermittent and variegate porphyria in this patient population, the risk of incurring symptoms after exposure to thiopental and/or other anesthetics was small [9].
• Propofol as an i.v. anaesthetic induction agent in variegate porphyria [10].
• The porphyrinogenicity of etomidate and ketamine administered as continuous i.v. infusions was screened in the DDC-primed rat model of latent variegate porphyria [11].
• We report on a 24-year-old woman with variegate porphyria who, after intake of lynestrenol, developed typical cutaneous lesions but no viscero-neurological symptoms [12].

Biological context of Porphyria, Variegate

• Mutation analysis of genomic DNA samples obtained from 17 unrelated South African patients with variegate porphyria (VP) revealed three novel missense mutations in the protoporphyrinogen oxidase (PPOX) gene [13].
• Partial characterization and assignment of the gene for protoporphyrinogen oxidase and variegate porphyria to human chromosome 1q23 [14].
• Identification of three mutations and associated haplotypes in the protoporphyrinogen oxidase gene in South African families with variegate porphyria [13].
• Lack of the R59W South African founder effect mutation in protoporphyrinogen oxidase in a British patient with homozygous variegate porphyria [15].
• Homozygous variegate porphyria: a compound heterozygote with novel mutations in the protoporphyrinogen oxidase gene [16].

Anatomical context of Porphyria, Variegate

• We measured the activities of protoporphyrinogen oxidase, which catalyzes the oxidation of protoporphyrinogen to protoporphyrin, and heme synthase, which catalyzes the chelation of iron to protoporphyrins, in cultured skin fibroblasts from five normal controls and five patients with variegate porphyria [17].
• Lymphocyte protoporphyrinogen oxidase activity was very low in the patient (0.4 nmol/mg protein/h) and half-normal (2.7 and 2.3 nmol/mg protein/h) in the parents, suggesting that the patient had homozygous variegate porphyria [18].

Gene context of Porphyria, Variegate

• The mutations reported here are the first to be described in patients with VP and support the conclusion that PPOX gene defects are disease causing mutations in human variegate porphyria [19].
• It is concluded that in variegate porphyria a partial block in heme biosynthesis results in subnormal capacity of P450-associated monooxygenases, but this is easily normalized by exogenous heme [8].
• The long-term follow-up of a homozygous variegate porphyria patient revealed severe photosensitivity accompanied by mild sensory neuropathy and IgA nephropathy [20].
• Expression and characterization of six mutations in the protoporphyrinogen oxidase gene among Finnish variegate porphyria patients [21].
• Of the 7 patients with hepatocellular carcinoma, 6 had acute intermittent porphyria and one had variegate porphyria [22].

References