21 Hydroxylase Deficiency
Mostrando 37-48 de 62 artigos, teses e dissertações.
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37. Mutations of P450c21 (steroid 21-hydroxylase) at Cys428, Val281, and Ser268 result in complete, partial, or no loss of enzymatic activity, respectively.
Steroid 21-hydroxylase deficiency is the major cause of congenital adrenal hyperplasia (CAH), a common genetic disease. To define the relationship between gene mutations and enzyme deficiency, we generated missense mutations of the 21-hydroxylase cDNA at three different sites and characterized the mutant proteins after expressing them in cultured mammalian a
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38. Prenatal diagnosis of congenital adrenal hyperplasia: reliability of amniotic fluid steroid analysis.
The concentration of 170H-progesterone was measured in amniotic fluid samples collected from 55 mothers who had previously had a child with congenital adrenal hyperplasia due to 21-hydroxylase deficiency. In eight pregnancies the levels of 170H-progesterone were raised; the parents elected to terminate in four and examinations of the fetus confirmed the diag
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39. Molecular characterization of the HLA-linked steroid 21-hydroxylase B gene from an individual with congenital adrenal hyperplasia.
21-Hydroxylase deficiency which causes congenital adrenal hyperplasia is one of the most common defects of adrenal steroidogenesis. There are two 21-hydroxylase genes in man, A and B, and these have been mapped to the HLA class III region. Only the 21-hydroxylase B gene is thought to be active. To understand the molecular basis of congenital adrenal hyperpla
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40. Non-expression of a common mutation in the 21-hydroxylase gene: implications for prenatal diagnosis and carrier testing.
Mutation analysis in the family of a child with 21-hydroxylase deficiency showed that the father and affected child were homozygous for a mutation, A/C655G, believed to activate a cryptic splice site in intron 2 of the 21-hydroxylase gene. The father, who was clinically asymptomatic, showed no biochemical evidence of disease. These results create problems fo
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41. Congenital adrenal hyperplasia due to 21‐hydroxylase deficiency is associated with a prolonged gestational age
BMJ Group.
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42. Gene conversion-like events cause steroid 21-hydroxylase deficiency in congenital adrenal hyperplasia.
Genomic DNAs from twelve Japanese patients with steroid 21-hydroxylase [21-OHase; steroid 21-monooxygenase; steroid, hydrogen-donor:oxygen oxidoreductase (21-hydroxylating); EC 1.14.99.10] deficiency were analyzed by Southern blot hybridization. A 3.7-kilobase (kb) Taq I and a 1.7-kb Pvu II restriction endonuclease fragment that correspond to a 21-OHase B ge
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43. Uniparental disomy for chromosome 6 results in steroid 21-hydroxylase deficiency: evidence of different genetic mechanisms involved in the production of the disease.
Congenital adrenal hyperplasia (CAH) is an inherited recessive disorder of adrenal steroidogenesis caused by mutations in the steroid 21-hydroxylase gene (CYP21) in more than 90% of affected patients. The CYP21 gene is located within the HLA complex locus on chromosome 6 (6p21.3). During a molecular characterisation study of a group of 47 Mexican families wi
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44. Molecular analysis of patient and carrier genes with congenital steroid 21-hydroxylase deficiency by using polymerase chain reaction and single strand conformation polymorphism.
Steroid 21-hydroxylase deficiency is a major cause of congenital adrenal hyperplasia and is caused by genetic impairment of this enzyme. Since approximately 80% of cases are caused by point mutations of the CYP21B (CYP21A2) gene, whereas the remaining 20% are due to deletion of this gene, we used the polymerase chain reaction single strand conformation polym
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45. Genetics and biochemical variability of variants of 21 hydroxylase deficiency.
In a population and family study we have examined the relationship between HLA types, classical congenital adrenal hyperplasia (CAH), and variants of 21 hydroxylase (21 OH) deficiency detected by increased blood levels of 17 hydroxyprogesterone (17 PO) in response to ACTH after overnight suppression with dexamethasone ('short Synacthen test'). In a non-CAH p
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46. Individuals with IgA deficiency and common variable immunodeficiency share polymorphisms of major histocompatibility complex class III genes.
IgA deficiency and common variable immunodeficiency are heritable disorders that can occur within the same family. Both immunodeficiencies are characterized by arrests in B-cell differentiation that vary in the extent of the immunoglobulin isotypes involved. A high frequency of major histocompatibility complex supratypes associated with a null allele of the
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47. Complete nucleotide sequence of two steroid 21-hydroxylase genes tandemly arranged in human chromosome: a pseudogene and a genuine gene.
Two 21-hydroxylase [P-450(C21)] genes have been isolated from a human genomic library using a bovine P-450(C21) cDNA. The insert DNAs containing the P-450(C21) genes were also hybridized with the sequences of the 5' or 3' end regions of human C4 cDNA, indicating a close linkage of the P-450(C21) gene to the C4 gene. Sequence analysis has revealed that the tw
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48. Defective antigen presentation and novel structural properties of DR1 from an HLA haplotype associated with 21-hydroxylase deficiency.
We have segregated DR1+ individuals into two categories according to whether or not their class II+ cells stimulated T lymphocyte clones specific for or restricted to DR1. In a majority of cases (87%), failure to stimulate was a property of cells having the B14;DR1 haplotype and/or nonclassical 21-hydroxylase deficiency. Absence of clonal proliferation could