Document Detail


Pericentric inversion of chromosome 9: prevalence in 300 Down syndrome families and molecular studies of nondisjunction.
MedLine Citation:
PMID:  1981475     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The incidence of Down syndrome (DS) families where one of the parents is an heterozygous carrier of pericentric inversion of the heterochromatic region of chromosome 9-inv(9) (qh) - was determined in 3 independent groups of 100 families each. The total number of 17 such families found in the sample is significantly greater than the expected number of 5.73 for a sample of non-DS families of equal size. Consequently, the statistical association of the presence of inv (9) (qh) in one parent with the birth of a DS offspring, and the correlative 3-fold increased risk of a DS child for such families, seem to be demonstrated. A study of the origin of nondisjunction, using restriction fragment length polymorphism (RFLP) segregation analysis with a sufficient number of chromosome 21 specific probes, has provided complete information in 7 of 8 available families. Although the statistical interpretation of the results is not straightforward, due to the small size of the sample, the observed data do not contradict the assumption that the presence of inv (9) (qh) in a parent increases, by a factor of about 3, the chance that the offspring will inherit an extra chromosome 21 from that parent. Nevertheless, gathering further data appears desirable because stronger evidence would have relevance both for clinical implications and for the understanding of the function of heterochromatin, particularly with respect to meiotic and mitotic processes.
Authors:
A Serra; C Brahe; A Millington-Ward; G Neri; B Tedeschi; F Tassone; R Bova
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  American journal of medical genetics. Supplement     Volume:  7     ISSN:  1040-3787     ISO Abbreviation:  Am J Med Genet Suppl     Publication Date:  1990  
Date Detail:
Created Date:  1991-04-16     Completed Date:  1991-04-16     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  8706133     Medline TA:  Am J Med Genet Suppl     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  162-8     Citation Subset:  IM    
Affiliation:
Istituto di Genetica Umana, Facoltà di Medicina A. Gemelli, U.C.S.C., Roma, Italy.
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MeSH Terms
Descriptor/Qualifier:
Chromosome Inversion*
Chromosomes, Human, Pair 9*
Down Syndrome / genetics*
Female
Genotype
Heterozygote
Homozygote
Humans
Infant, Newborn
Male
Nondisjunction, Genetic*
Polymorphism, Restriction Fragment Length
Risk Factors

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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