Linked Life Data

7881406

Source:http://linkedlifedata.com/resource/pubmed/id/7881406

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1995-4-13
pubmed:abstractText
This study of allelic association using three intra- and two extragenic markers within 150 kb of the Huntington disease (HD) mutation has provided evidence for linkage disequilibrium for four of five markers. Haplotype analysis of 67 HD families using markers in strong linkage disequilibrium with HD identified two haplotypes underlying 77.6% of HD chromosomes. Normal chromosomes with these two haplotypes had a mean number of CAG repeats significantly larger than and an altered distribution of CAG repeats compared with other normal chromosomes. Furthermore, haplotype analysis of five new mutation families reveals that HD has arisen on these same two chromosomal haplotypes. These findings suggest that HD arises more frequently on chromosomes with specific DNA haplotypes and higher CAG repeat lengths. We then studied CAG and CCG repeat lengths in the HD gene on 896 control chromosomes from different ancestries to determine whether the markedly reduced frequency of HD in Finland, Japan, China and African Blacks is associated with an altered frequency of DNA haplotypes and subsequently lower CAG lengths on control chromosomes compared to populations of Western European descent. The results show a highly significant inverse relationship between CAG and CCG repeat lengths. In populations with lowered prevalence rates of HD, CAG repeat lengths are smaller and the distribution of CCG alleles is markedly different from Western European populations. These findings suggest that, in addition to European emigration, new mutations make a contribution to geographical variation of prevalence rates and is consistent with a multistep model of HD developing from normal chromosomes with higher CAG repeat lengths.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0964-6906
pubmed:author
pubmed:issnType
Print
pubmed:volume
3
pubmed:geneSymbol
HD
pubmed:owner
NLM
pubmed:authorsComplete
N
pubmed:pagination
2103-14
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
DNA haplotype analysis of Huntington disease reveals clues to the origins and mechanisms of CAG expansion and reasons for geographic variations of prevalence.
pubmed:affiliation
Department of Medical Genetics, University of British Columbia, Vancouver, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't