Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phenotypic and molecular analysis of individuals with partial trisomy 21 can be used to determine which regions of chromosome 21 are involved in the pathogenesis of specific features of Down's Syndrome. Using dosage analysis of 27 sequences we defined, at the molecular level, the extent of the chromosome 21 duplication in ten individuals with partial trisomy 21. Phenotype-genotype correlations led to the definition of minimal regions, the duplications of which are linked to the expression of 23 clinical features of Down's Syndrome. The D21S55 region or Down's Syndrome Chromosome Region 1 (DCR1) (1/20 of the long arm), on 21q22.2-21q22.3 proximal, is involved in four cardinal features of the disease: mental retardation, growth retardation, muscular hypotonia and joint hyperlaxity, and in eight of the 18 more common morphological anomalies of the face, hands and feet. Overlapping the DCR1, the D21S55-MX1 region or DCR2 (1/10 of the long arm), spanning 21q21.2 down to the 1/4th proximal part of 21q22.3, is involved in the features defined by the DCR1 plus congenital heart defect and five additional morphological anomalies. Thus, our results indicate that duplication of a relatively small region of chromosome 21 plays a critical role in the pathogenesis of the Down's phenotype.
 ...
PMID:Mapping of the Down syndrome phenotype on chromosome 21 at the molecular level. 799 86

To determine which regions of chromosome 21 are involved in the pathogenesis of specific features of Down syndrome, we analysed, phenotypically and molecularly, 10 patients with partial trisomy 21. Six minimal regions for 24 features were defined by genotype-phenotype correlations. Nineteen of these features could be assigned to just 2 regions: short stature, joint hyperlaxity, hypotonia, major contribution to mental retardation and 9 anomalies of the face, hand and foot to the region D21S55, or Down syndrome chromosome region (DCR), located on q22.2 or very proximal q22.3, and spanning 0.4-3 Mb; 6 facial and dermatoglyphic anomalies to the region D21S55-MX1, including the DCR and spanning a maximum of 6 Mb on q22.2 and part of q22.3. Thus, the complex phenotype that constitutes Down syndrome may in large part simply result from the overdosage of only one or a few genes within the DCR and/or region D21S55-MX1.
 ...
PMID:Molecular mapping of twenty-four features of Down syndrome on chromosome 21. 805 22

We have isolated, mapped and sequenced the 5' promoter region of the human SH3BGR (SH3-Binding Glutamine Rich) gene located in the Down syndrome region-2, between markers D21S55 and MX1 of human chromosome 21. This region has been postulated as the minimal region for congenital heart disease and 6 facial and dermatoglyphic features present in Down syndrome. The SH3BGR gene is expressed in fetal and adult heart and in skeletal muscle and therefore it is a candidate gene for the congenital heart defect and muscle hypotonia. The 5' region of the gene has been positioned in a 115 kb PAC/cosmid contig with full EcoRI/SmaI restriction map covering cosmid pockets 122-123 as well as cosmid pocket 124 located between markers D21S268 and D21S220. Sequencing of the SH3BGR promoter region has allowed the identification of several potential regulatory elements of this candidate gene for the congenital heart disease and other potential DS features. Several of the elements identified are also present in other muscle-expressed genes.
 ...
PMID:High-resolution physical map and identification of potentially regulatory sequences of the human SH3BGR located in the Down syndrome chromosomal region. 942 70