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Title: Down syndrome: Molecular mapping of the congenital heart disease and duodenal stenosis

Abstract

Down syndrome (DS) is a major cause of congenital heart and gut disease and mental retardation. DS individuals also have characteristic facies, hands, and dermatoglyphics, in addition to abnormalities of the immune system, and increased risk of leukemia, and an Alzheimer-like dementia. Although their molecular basis is unknown, recent work on patients with DS and partial duplications of chromosome 21 has suggested small chromosomal regions located in band q22 that are likely to contain the genes for some of these features. The authors now extend these analyses to define molecular markers for the congenital heart disease, the duodenal stenosis, and an 'overlap' region for the facial and some of the skeletal features. They report the clinical, cytogenetic, and molecular analysis of two patients. These studies provide the molecular basis for the construction of a DS phenotypic map and focus the search for genes responsible for the physical features, congenital heart disease, and duodenal stenosis of DS.

Authors:
 [1]; ;  [2]
  1. (University of California, Los Angeles (United States))
  2. (University of Washington, Seattle (United States))
Publication Date:
OSTI Identifier:
7176558
Alternate Identifier(s):
OSTI ID: 7176558
Resource Type:
Journal Article
Resource Relation:
Journal Name: American Journal of Human Genetics; (United States); Journal Volume: 50:2
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; HEREDITARY DISEASES; ETIOLOGY; HUMAN CHROMOSOME 21; GENETIC MAPPING; BIOLOGICAL MARKERS; CARDIOVASCULAR DISEASES; CONGENITAL DISEASES; PATIENTS; SMALL INTESTINE; BODY; CHROMOSOMES; DIGESTIVE SYSTEM; DISEASES; GASTROINTESTINAL TRACT; HUMAN CHROMOSOMES; INTESTINES; MAPPING; ORGANS 550400* -- Genetics

Citation Formats

Korenburg, J.R., Bradley, C., and Disteche, C.M. Down syndrome: Molecular mapping of the congenital heart disease and duodenal stenosis. United States: N. p., 1992. Web.
Korenburg, J.R., Bradley, C., & Disteche, C.M. Down syndrome: Molecular mapping of the congenital heart disease and duodenal stenosis. United States.
Korenburg, J.R., Bradley, C., and Disteche, C.M. Sat . "Down syndrome: Molecular mapping of the congenital heart disease and duodenal stenosis". United States. doi:.
@article{osti_7176558,
title = {Down syndrome: Molecular mapping of the congenital heart disease and duodenal stenosis},
author = {Korenburg, J.R. and Bradley, C. and Disteche, C.M.},
abstractNote = {Down syndrome (DS) is a major cause of congenital heart and gut disease and mental retardation. DS individuals also have characteristic facies, hands, and dermatoglyphics, in addition to abnormalities of the immune system, and increased risk of leukemia, and an Alzheimer-like dementia. Although their molecular basis is unknown, recent work on patients with DS and partial duplications of chromosome 21 has suggested small chromosomal regions located in band q22 that are likely to contain the genes for some of these features. The authors now extend these analyses to define molecular markers for the congenital heart disease, the duodenal stenosis, and an 'overlap' region for the facial and some of the skeletal features. They report the clinical, cytogenetic, and molecular analysis of two patients. These studies provide the molecular basis for the construction of a DS phenotypic map and focus the search for genes responsible for the physical features, congenital heart disease, and duodenal stenosis of DS.},
doi = {},
journal = {American Journal of Human Genetics; (United States)},
number = ,
volume = 50:2,
place = {United States},
year = {Sat Feb 01 00:00:00 EST 1992},
month = {Sat Feb 01 00:00:00 EST 1992}
}
  • We report on two brothers and their two maternal uncles with severe mental retardation, congenital heart defect, cleft or highly arched palate, short stature and craniofacial anomalies consisting of microcephaly, abnormal ears, bulbous nose, broad nasal bridge, malar hypoplasia, and micro-gnathia. Three of the four patients died at an early age. The mother of the two brothers had an atrial septal defect. She is assumed to be manifesting carrier of a mutant gene, which is expressed in her two sons and two brothers. By multipoint linkage analysis it is found that the most likely location of the responsible gene ismore » the pericentromeric region Xp21.3-q21.3 with DMD and DXS3 as flanking markers. Maximum information is obtained with marker DXS453 (Z = 1.20 at {theta} = 0.0). 24 refs., 12 figs., 1 tab.« less
  • Mouse trisomy 16 has been proposed as an animal model of Down syndrome (DS), since this chromosome contains homologues of several loci from the q22 band of human chromosome 21. The recent mapping of the defect causing familial Alzheimer disease (FAD) and the locus encoding the Alzheimer amyloid {beta} precursor protein (APP) to human chromosome 21 has prompted a more detailed examination of the extent of conservation of this linkage group between the two species. Using anonymous DNA probes and cloned genes from human chromosome 21 in a combination of recombinant inbred and interspecific mouse backcross analyses, the authors havemore » established that the linkage group shared by mouse chromosome 16 includes not only the critical DS region of human chromosome 21 but also the APP gene and FAD-linked markers. Extending from the anonymous DNA locus D21S52 to ETS2, the linkage map of six loci spans 39% recombination in man but only 6.4% recombination in the mouse. A break in synteny occurs distal to ETS2, with the homologue of the human marker D21S56 mapping to mouse chromosome 17. Conservation of the linkage relationships of markers in the FAD region suggests that the murine homologue of the FAD locus probably maps to chromosome 16 and that detailed comparison of the corresponding region in both species could facilitate identification of the primary defect in this disorder. The break in synteny between the terminal portion of human chromosome 21 and mouse chromosome 16 indicates, however, that mouse trisomy 16 may not represent a complete model of DS.« less
  • Although duodenal atresia (DA) is present in only 4-7% of all Down Syndrome (DS) individuals, 30-50% of all congenital duodenal atresias occur in the DS population, suggesting the presence of gene(s) on chromosome 21 that play an important role in intestinal development. We recently proposed a chromosome 21 gene dosage model to explain the phenotypic variance seen among DS individuals and presented a strategy to map genes involved in these phenotypic traits. We suggest that {open_quote}hyper-dosage{close_quote} resulting from normal allelic differences explains the phenotypic variation. A proportion of trisomic genotypes would exceed some activity threshold and express the trait. Inmore » affected individuals, this increase in expression is due to the presence of two identical copies of {open_quote}susceptibility{close_quote} allele, inherited from a heterozygous parent of origin. Individuals with trisomy 21 and a specific phenotypic defect should exhibit increased levels of disomic homozygosity in the region containing the gene involved in the defect`s etiology. These data can be used to map these genes. Using this approach, we have examined markers along the long arm of chromosome 21 among DS individuals with DA and determined the degree of disomic homozygosity at each marker. This frequency was compared to the level of disomic homozygosity among our entire DS study population consisting of approximately 380 DS families to test for linkage between DA and each marker. Preliminary analysis of 13 DS cases with DA indicates an increase in disomic homozygosity along the distal region of the chromosome, from HMG14 to D21S171, the most telomeric marker analyzed. An additional 15 cases are currently being analyzed to confirm and better define this candidate region.« less