title: Enzymatic and immunological studies of uroporphyrinogen decarboxylase in familial porphyria cutanea tarda and hepatoerythropoietic porphyria.
abstract: Uroporphyrinogen decarboxylase activity was measured in hemoglobin-free lysates from two patients with hepatoerythropoietic porphyria (HEP) and from 12 unrelated patients with familial porphyria cutanea tarda (PCT). In HEP patients, enzyme activities were 5% of normal, and familial studies clearly confirmed that patients with HEP are cases of homozygous PCT. Immunoreactive uroporphyrinogen decarboxylase was measured by developing a direct and noncompetitive enzyme immunoassay (EIA). For the 12 familial PCT patients, we found an immunoreactive protein decreased (51%) to the same extent as the catalytic activity (48%) [cross-reactive immunological material ( CRIM ) negative]. The children from the HEP family were also CRIM negative, contrasting with another HEP family previously described as CRIM positive; our data support the hypothesis of a heterogeneity in familial uroporphyrinogen decarboxylase deficiency.
mesh_terms: D002262:Carboxy-Lyases / Q000172:deficiency*; D002648:Child; D004200:Diseases in Twins; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D006720:Homozygote; D006801:Humans; D007124:Immunoenzyme Techniques; D008107:Liver Diseases / Q000201:enzymology / Q000235:genetics*; D008297:Male; D010375:Pedigree; D011164:Porphyrias / Q000201:enzymology / Q000235:genetics*; D011166:Porphyrins / Q000032:analysis; D012871:Skin Diseases / Q000201:enzymology / Q000235:genetics*; D014575:Uroporphyrinogen Decarboxylase / Q000032:analysis / Q000172:deficiency*
chemical_list: D011166:Porphyrins; D002262:Carboxy-Lyases; D014575:Uroporphyrinogen Decarboxylase