Hereditary coproporphyria (HCP). Coproporphyrinogen oxidase (COPRO) deficiency
Incidence
AD disease. It occur in heterozygous affecyed pts. Enzyme is deficient by 50%. Gene is located in chromosome 9.
Clinical Characteristics
The clinical symptoms are similar to Acute Intermittent Porphyria. Cutaneous photosensitivity is prominent. There may be liver involvement. There is excessive excretion of coproporphyrin in urine and feces. Also there is high levels of ALA and PBG in urine between attacks.
Precipitants
Barbiturates, antiepileptic drugs, sulfas, ergotamine, chloroquine and other drugs may trigger an attack.
Provocation Tests
Not recommended
Diagnostic Procedures
There is excessive excretion of coproporphyrin in urine and feces. Also there is high levels of ALA and PBG in urine between attacks.