Type
Enzyme
Clinical features
5-aminolevulinic acid dehydratase porphyria
5-aminolevulinic acid dehydratase
Rare, primarily neurological symptoms, no photosensitivity [2]
Acute intermittent porphyria
Porphobilinogen deaminase
The most common acute form of porphyria. Intermittent neurological symptoms (up to 80 % of carriers are asymptomatic), no photosensitivity. Symptoms usually after puberty, more prevalent in females than in males [2]
Congenital erythropoietic porphyria
Uroporphyrinogen III synthetase
Anemia and photosensitivity. Extremely variable severity ranging from fetal hydrops to mild photosensitivity in adults. Hypertrichosis [1]
Porphyria cutanea tarda
Uroporphyrinogen decarboxylase
Anemia and photosensitivity. Sporadic cases are common. Photosensitivity is severe, presenting in the first year of life in familial cases. Symptoms respond to phlebotomy and low-dose chloroquine and hydroxychloroquine. Associated with alcohol use and chronic hepatitis C [1]
Hereditary coproporphyria
Coproporphyrinogen oxidase
Intermittent neurological symptoms, mild photosensitivity
Variegate porphyria
Protoporphyrinogen oxidase (PPO)
Erythropoietic protoporphyria
Ferrochelatase
Disease | Classification | Gene | Location | Inheritance |
|---|---|---|---|---|
5-aminolevulinic acid dehydratase porphyria | Hepatic | ALAD | 9q32 | Recessive |
Acute intermittent porphyria | Hepatic | HMBS | 11q23.3 | Dominant |
Congenital erythropoietic porphyria | Erythropoietic | UROS | 10q26.1–q26.2 | Recessive |
Porphyria cutanea tarda | Hepatic | UROD | 1p34.1 | Type 1 sporadic Type 2 – dominant |
Hereditary coproporphyria | Hepatic | CPOX | 3q11.2–q12.1 | Dominant |
Variegate porphyria | Hepatic | PPOX | 1q23.3 | Dominant |
Erythropoietic protoporphyria | Erythropoietic | FECH | 18q21.31 | Dominant |
How did I get it?
- (a)
Genetics of porphyrias.
Most porphyrias are autosomal dominant, although rare recessive disorders (ALAD deficiency porphyria [ADP] , CEP) have been described. Sporadic forms, where symptoms are induced by a combination of external and endogenous factors rather than gene mutation, are common in patients with symptoms of PCT, with the adult population reported to have an association with alcohol use and chronic hepatitis C. “Dual porphyrias,” where a single patient has mutations in two separate genes in the heme synthesis pathway, have also been described [1].Related posts:
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