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Studies in porphyria. IV. Expression of the gene defect of acute intermittent porphyria in cultured human skin fibroblasts and amniotic cells: prenatal diagnosis of the porphyric trait

The gene lesion of the porphyrin-heme synthetic pathway in acute intermittent porphyria (AIP) is reflected in a deficient level of activity of the cytosol enzyme uroporphyrinogen I synthetase (URO-S). A marked URO-S deficiency has been demonstrated in the liver and in circulating erythrocytes of ind...

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Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1975
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2189917/
https://www.ncbi.nlm.nih.gov/pubmed/1165472
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description The gene lesion of the porphyrin-heme synthetic pathway in acute intermittent porphyria (AIP) is reflected in a deficient level of activity of the cytosol enzyme uroporphyrinogen I synthetase (URO-S). A marked URO-S deficiency has been demonstrated in the liver and in circulating erythrocytes of individuals with both active and latent AIP. This enzymic abnormality accounts for the excessive production and excretion into urine of the porphyrin precursors, lamda-aminolevulinic acid (ALA) and porphobilinogen (PBG) in AIP subjects. In this study, utilizing cell culture techniques, a marked URO-S deficiency has also been demonstrated in skin fibroblasts from AIP patients and in cells derived through aminocentesis from an approximately 17-wk old fetus. The prenatal diagnosis of the AIP trait in this fetus was confirmed postnatally by the demonstration in the child of a deficient level of erythrocyte URO-S activity which was comparable to those found in her AIP mother and affected sibling and which was approximately one-half the levels characterizing her normal father and aunt and a second unaffected sibling. The identification of the URO-S deficiency in cultured human fibroblasts from AIP patients was facilitated by a newly developed, sensitive assay for the enzyme activity. In this assay, the ability of such cells to convert ALA to protoporphyrin was quantitated; in the sequence of reactions involved in this transformation, URO-S is limiting so that the gene defect of AIP could be simply and precisely determined by appropriate spectrofluorometry of cell extracts. The technique described has distinct advantages over the direct enzymatic assay for URO-S activity in cultured human skin fibroblasts and permits clear differentiation of AIP carrier from normal individuals.
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spelling pubmed-21899172008-04-17 Studies in porphyria. IV. Expression of the gene defect of acute intermittent porphyria in cultured human skin fibroblasts and amniotic cells: prenatal diagnosis of the porphyric trait J Exp Med Articles The gene lesion of the porphyrin-heme synthetic pathway in acute intermittent porphyria (AIP) is reflected in a deficient level of activity of the cytosol enzyme uroporphyrinogen I synthetase (URO-S). A marked URO-S deficiency has been demonstrated in the liver and in circulating erythrocytes of individuals with both active and latent AIP. This enzymic abnormality accounts for the excessive production and excretion into urine of the porphyrin precursors, lamda-aminolevulinic acid (ALA) and porphobilinogen (PBG) in AIP subjects. In this study, utilizing cell culture techniques, a marked URO-S deficiency has also been demonstrated in skin fibroblasts from AIP patients and in cells derived through aminocentesis from an approximately 17-wk old fetus. The prenatal diagnosis of the AIP trait in this fetus was confirmed postnatally by the demonstration in the child of a deficient level of erythrocyte URO-S activity which was comparable to those found in her AIP mother and affected sibling and which was approximately one-half the levels characterizing her normal father and aunt and a second unaffected sibling. The identification of the URO-S deficiency in cultured human fibroblasts from AIP patients was facilitated by a newly developed, sensitive assay for the enzyme activity. In this assay, the ability of such cells to convert ALA to protoporphyrin was quantitated; in the sequence of reactions involved in this transformation, URO-S is limiting so that the gene defect of AIP could be simply and precisely determined by appropriate spectrofluorometry of cell extracts. The technique described has distinct advantages over the direct enzymatic assay for URO-S activity in cultured human skin fibroblasts and permits clear differentiation of AIP carrier from normal individuals. The Rockefeller University Press 1975-09-01 /pmc/articles/PMC2189917/ /pubmed/1165472 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Articles
Studies in porphyria. IV. Expression of the gene defect of acute intermittent porphyria in cultured human skin fibroblasts and amniotic cells: prenatal diagnosis of the porphyric trait
title Studies in porphyria. IV. Expression of the gene defect of acute intermittent porphyria in cultured human skin fibroblasts and amniotic cells: prenatal diagnosis of the porphyric trait
title_full Studies in porphyria. IV. Expression of the gene defect of acute intermittent porphyria in cultured human skin fibroblasts and amniotic cells: prenatal diagnosis of the porphyric trait
title_fullStr Studies in porphyria. IV. Expression of the gene defect of acute intermittent porphyria in cultured human skin fibroblasts and amniotic cells: prenatal diagnosis of the porphyric trait
title_full_unstemmed Studies in porphyria. IV. Expression of the gene defect of acute intermittent porphyria in cultured human skin fibroblasts and amniotic cells: prenatal diagnosis of the porphyric trait
title_short Studies in porphyria. IV. Expression of the gene defect of acute intermittent porphyria in cultured human skin fibroblasts and amniotic cells: prenatal diagnosis of the porphyric trait
title_sort studies in porphyria. iv. expression of the gene defect of acute intermittent porphyria in cultured human skin fibroblasts and amniotic cells: prenatal diagnosis of the porphyric trait
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2189917/
https://www.ncbi.nlm.nih.gov/pubmed/1165472