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Predicate | Object |
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rdf:type | |
lifeskim:mentions |
umls-concept:C0003765,
umls-concept:C0010654,
umls-concept:C0011155,
umls-concept:C0017797,
umls-concept:C0019425,
umls-concept:C0026882,
umls-concept:C0038302,
umls-concept:C0205147,
umls-concept:C0205195,
umls-concept:C0205198,
umls-concept:C0205409,
umls-concept:C0723457,
umls-concept:C1524003,
umls-concept:C1707271,
umls-concept:C1853126,
umls-concept:C1947925,
umls-concept:C2746065
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pubmed:issue |
4
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pubmed:dateCreated |
1992-10-6
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pubmed:abstractText |
The molecular defect in a reported case of isolated 17,20-lyase deficiency in a 46XY individual has been elucidated. The patient was found to be a compound heterozygote, carrying two different mutant alleles in the CYP17 gene. One allele contains a point mutation of arginine (CGC) to cysteine (TGC) at amino acid 496 in exon 8. The second allele contains a stop codon (TAG) in place of glutamine (CAG) at position 461 in exon 8 which is located 19 amino acids to the carboxy-terminal side of the P-450(17) alpha heme binding cysteine. COS-1 cells transfected with cDNAs containing one or the other of these mutations showed dramatically reduced 17 alpha-hydroxylase and 17,20-lyase activities relative to cells transfected with the wild type P-450(17) alpha cDNA. While the in vitro data in COS 1 cells can explain the patient's physical phenotype, with female external genitalia, it was somewhat discordant with the clinical expression of isolated 17,20-lyase deficiency with relative preservation of 17 alpha-hydroxylase activity in vivo. In addition to the expression studies of these two examples of mutants in the C-terminal region of cytochrome P-450(17) alpha, a third mutant cDNA construct containing a 4-base duplication at codon 480 previously found in patients with combined 17 alpha-hydroxylase/17,20-lyase deficiency was also expressed in COS-1 cells. This expressed protein was completely inactive with respect to both activities, supporting the biochemical findings in serum and in vitro biochemical data obtained using a testis from the patient. The results from these patients clearly indicate the importance of the C-terminal region of human P-450(17) alpha in its enzymatic activities.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Aug
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pubmed:issn |
0006-3002
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
25
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pubmed:volume |
1139
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pubmed:geneSymbol |
CYP17
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
275-9
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pubmed:dateRevised |
2010-11-18
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pubmed:meshHeading |
pubmed-meshheading:1515452-Adolescent,
pubmed-meshheading:1515452-Adrenal Hyperplasia, Congenital,
pubmed-meshheading:1515452-Aldehyde-Lyases,
pubmed-meshheading:1515452-Amino Acid Sequence,
pubmed-meshheading:1515452-Base Sequence,
pubmed-meshheading:1515452-Cell Line,
pubmed-meshheading:1515452-Cytochrome P-450 Enzyme System,
pubmed-meshheading:1515452-Disorders of Sex Development,
pubmed-meshheading:1515452-Heterozygote,
pubmed-meshheading:1515452-Humans,
pubmed-meshheading:1515452-Male,
pubmed-meshheading:1515452-Molecular Sequence Data,
pubmed-meshheading:1515452-Mutation,
pubmed-meshheading:1515452-Transfection
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pubmed:year |
1992
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pubmed:articleTitle |
Molecular basis of apparent isolated 17,20-lyase deficiency: compound heterozygous mutations in the C-terminal region (Arg(496)----Cys, Gln(461)----Stop) actually cause combined 17 alpha-hydroxylase/17,20-lyase deficiency.
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pubmed:affiliation |
Department of Biochemistry and Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas 75235.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Case Reports,
Research Support, Non-U.S. Gov't
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