Linked Life Data

8481357

Source:http://linkedlifedata.com/resource/pubmed/id/8481357

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-3
pubmed:dateCreated
1993-6-1
pubmed:abstractText
Steroid 11 beta-hydroxylase is encoded by two homologous genes, CYP11B1 and CYP11B2, located on chromosome 8q21-22. CYP11B1 encodes a specific cytochrome P-450 (P-450c11) necessary for cortisol biosynthesis, with predominantly 11 beta-hydroxylase and moderate 18-hydroxylase activity, whereas CYP11B2 encodes another isozyme (P-450cmo) necessary for aldosterone biosynthesis, with 11 beta-hydroxylase, 18-hydroxylase and 18-oxidase activities (the latter two termed corticosterone methyl-oxidase I and II; CMO-I and II, respectively). Two steroid biosynthetic defects, both relatively frequent in Israel, are caused by specific mutations in each of these genes. 11 beta-Hydroxylase deficiency is frequent among Jews from Morocco (1 in 5000 to 7000 births), and is characterized by virilization, hypertension, impaired cortisol biosynthesis, and increased deoxycorticosterone and androgens. Affected individuals have a single base substitution in exon 8 of CYP11B1, codon 448, from CGC (arginine) to CAC (histidine). This sequence, normally absent in CYP11B2, constitutes a true point mutation within the heme binding domain of CYP11B1 that results in marked impairment of enzymatic activity. The clinical expression is characterized by a wide range of variability in the signs of both androgen and mineralocorticoid excess, even though an identical mutation was found in all but one of the affected alleles examined. CMO-II deficiency is frequent among Jews from Iran (1 in 4000 births), and is characterized by a typical salt-wasting syndrome, increased 18-hydroxycorticosterone, impaired aldosterone biosynthesis, and a high ratio of these steroids. No mutation was found in CYP11B1, but all individuals affected were homozygous for two missense mutations in CYP11B2. The first, in exon 3, codon 181, from CGG (arginine) to TGG (tryptophane) is a mutation that completely abolishes both CMO-I and II activities, whereas the second, in exon 7, codon 386, from GTG (valine) to GCG (alanine) is a more conservative substitution that produces only a minimal reduction in CMO-I activity. Individuals homozygous for either one of these mutations are asymptomatic.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0960-0760
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:geneSymbol
CYP11B1, CYP11B2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
99-106
pubmed:dateRevised
2005-11-16
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Mutations in human 11 beta-hydroxylase genes: 11 beta-hydroxylase deficiency in Jews of Morocco and corticosterone methyl-oxidase II deficiency in Jews of Iran.
pubmed:affiliation
Department of Endocrinology and Metabolism, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
pubmed:publicationType
Journal Article, Review