[Enzymatic and molecular studies in a case of hepato-erythropoietic porphyria. Homozygote form of type familial cutaneous porphyria].
BACKGROUND
Porphyrias are either hepatic or erythroid, depending on the principal site of the specific enzymatic defect. Homozygous uroporphyrinogen decarboxylase deficiency, known as hepato-erythropoietic porphyria (HEP), can involve several mutations.


METHODS
A young man, aged 20 years, had gradually developed photosensitivity since the age of 1 year, leading to hypertrichosis and sclerodermoid changes in sun-exposed areas of skin. He displayed high urinary uroporphyrin and 7-carboxylic porphyrins, and elevated fecal and red blood cell iso-coproporphyrin and coproporphyrin. Erythrocyte uroporphyrinogen decarboxylase activity of the patient was reduced to 18% of normal control values, while those of his grandmother and his half-brother were 62-65% of normal.
Amplification of the genomic DNA by PCR and hybridization with allele-specific oligonucleotides (ASOs) demonstrated the presence of a Gly 281-->Glu mutation in the patient and in his grandmother and half-brother.


CONCLUSIONS
Enzymatic studies and details of the familial lineage are important for precisely classifying this type of porphyria. Molecular biology studies are necessary before considering any future gene therapy.
Département de Biochimie Médicale et Biologie Moléculaire, Université de Bordeaux II.
H
H
de Verneuil
F
F
Moreau-Gaudry
S
S
Laradi
M J
MJ
Cruces
C
C
de la Torre
L F
LF
Aris
D000328:Adult; D005500:Follow-Up Studies; D006720:Homozygote; D006801:Humans; D008297:Male; D008967:Molecular Biology; D017119:Porphyria Cutanea Tarda / Q000235:genetics*; D017121:Porphyria, Hepatoerythropoietic / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D014575:Uroporphyrinogen Decarboxylase / Q000378:metabolism
D014575:Uroporphyrinogen Decarboxylase
Etudes enzymatique et moléculaire d'un cas de porphyrie hépato-érythrocytaire. Forme homozygote de la porphyrie cutanée de type familial.