PCT is generally sporadic, but about 20-30% of patients have familial-PCT (F-PCT) which is associated with heterozygosity of mutations in the UROD gene.
UROD activity has a high diagnostic accuracy for differentiating the 2 PCT types, and a model that takes into account both clinical information and laboratory test results can be used to predict fPCT.
However, possible disease-related UROD mutations were identified in 24% of the examined patients, indicating that genetic analysis of PCT patients may improve differentiation between familial and sporadic PCT cases.
The DGGE assay presented greatly improves the genetic diagnosis of fPCT and HEP, thereby facilitating the detection of familialUROD deficient patients as well as the discrimination between familial and sporadic PCT cases.
HLA phenotypes were determined in 69 porphyria cutanea tarda patients, 42 of which had the sporadic type (normal erythrocyte uroporphyrinogen decarboxylase activity) and 27 unrelated patients who had the familial type (diminished erythrocyte uroporphyrinogen decarboxylase activity).
Immunoreactive and catalytic uroporphyrinogen decarboxylase were measured in liver from 15 patients with sporadic porphyria cutanea tarda (PCT) and 4 patients with familial PCT at different stages of the disorder.