Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Progress in complete genomic sequencing of human chromosome 21 relies on the construction of high-quality bacterial clone maps spanning large chromosomal regions. To achieve this goal, we have applied a strategy based on nonradioactive hybridizations to contig building. A contiguous sequence-ready map was constructed in the Down syndrome congenital heart disease (DS-CHD) region in 21q22.2, as a framework for large-scale genomic sequencing and positional candidate gene approach. Contig assembly was performed essentially by high throughput nonisotopic screenings of genomic libraries, prior to clone validation by (1) restriction digest fingerprinting, (2) STS analysis, (3) Southern hybridizations, and (4) FISH analysis. The contig contains a total of 50 STSs, of which 13 were newly isolated. A minimum tiling path (MTP) was subsequently defined that consists of 20 PACs, 2 BACs, and 5 cosmids covering 3 Mb between D21S3 and MX1. Gene distribution in the region includes 9 known genes (c21-LRP, WRB, SH3BGR, HMG14, PCP4, DSCAM, MX2, MX1, and TMPRSS2) and 14 new additional gene signatures consisting of cDNA selection products and ESTs. Forthcoming genomic sequence information will unravel the structural organization of potential candidate genes involved in specific features of Down syndrome pathogenesis.
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PMID:A contiguous 3-Mb sequence-ready map in the S3-MX region on 21q22.2 based on high- throughput nonisotopic library screenings. 1020 58

The SH3BGR gene has been recently isolated and mapped to chromosome 21 within the Down syndrome (DS) congenital heart disease (CHD) minimal region. As a first step to evaluate the possible involvement of SH3BGR in CHD that affect 40% of DS patients, we have analyzed by in situ hybridization the expression pattern of the mouse homolog gene (Sh3bgr), during development. Our results show that Sh3bgr is already expressed at embryonic day 7.75 (E7.75) in the precardiogenic mesoderm and that from E8.5 to E10.5 its expression is restricted to the heart. In subsequent developmental stages, Sh3bgr transcripts are also detected in skeletal muscle and in some visceral smooth muscles including urinary bladder and gut wall, but not in vascular smooth muscle. Our results, demonstrating that Sh3bgr is expressed in earliest stages of mouse heart development, support a possible role of this gene in heart morphogenesis and, consequently, in the pathogenesis of CHD in DS.
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PMID:Developmental expression of the SH3BGR gene, mapping to the Down syndrome heart critical region. 1064 Jul 19

We report a case of a child with features of Down syndrome (DS) but with an atypical karyotype. Initial chromosome analysis was 46,XX,dup(21q).ish 21(wcp21+). The father's chromosomes were normal. However, the mother was found to have mosaicism for a pericentric inversion of chromosome 21 (19/30 cells). The revised chromosome result of the child was 46,XX,rec(21)dup(21q)inv(21)(p12q21.1)mat. A literature review of similar cases (hereafter referred to as rec dup(21q)) was conducted to aid counselling about recurrence risks and the prognosis for this child. All previous reports of rec dup(21q) were secondary to a maternal pericentric inversion. Male carriers did not seem to be at risk of having offspring with the rec dup(21q), although the number of male carriers was limited. In those with rec dup(21q), the risk of congenital heart disease was similar to that of trisomy 21. In reported cases, the facial appearance was suggestive of Down syndrome but perhaps less striking. Although the data are limited, there is an indication the developmental disabilities and short stature are milder in those with rec dup(21q) compared to trisomy 21. These observations promote the concept that the region of chromosome 21 proximal to the duplication contains genetic information contributing to the expression of some features of Down syndrome.
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PMID:Recombinant Down syndrome: a case report and literature review. 1126 Feb 15

An extra copy of human chromosome 21 (Chr 21) causes Down syndrome (DS), which is characterized by mental retardation and congenital heart disease (CHD). Chimeric mice containing Chr 21 also exhibit phenotypic traits of DS including CHD. In this study, to identify genes contributing to DS phenotypes, we compared the overall protein expression patterns in hearts of Chr 21 chimeras and wild type mice by two-dimensional electrophoresis. The endogenous mouse atrial specific isoform of myosin light chain-2 (mlc-2a) protein was remarkably downregulated in the hearts of chimeric mice. We also confirmed that the human MLC-2A protein level was significantly lower in a human DS neonate heart, as compared to that of a normal control. Since mouse mlc-2a is involved in heart morphogenesis, our data suggest that the downregulation of this gene plays a crucial role in the CHD observed in DS. The dosage imbalance of Chr 21 has a trans-acting effect which lowers the expression of other genes encoded elsewhere in the genome.
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PMID:An extra human chromosome 21 reduces mlc-2a expression in chimeric mice and Down syndrome. 1208 76

The SH3 binding glutamic acid-rich (SH3BGR) gene was cloned in an effort to identify genes located to human chromosome 21, within the congenital heart disease region, and expressed in the developing heart. After the identification of SH3BGR, two human homologous genes, SH3BGRL and SH3BGRL3, were identified and mapped to chromosome Xq13.3 and 1p34.3-35, respectively. SH3BGRL and SH3BGRL3 code for small proteins similar to the N-terminal region of the SH3BGR protein. SH3BGRL3 protein shows a significant similarity to Glutaredoxin 1 of Escherichia coli, and all the three proteins are predicted to belong to Thioredoxin-like protein Superfamily. Here we describe the identification and characterization of an additional human homologue of SH3BGR, named SH3BGRL2. The SH3BGRL2 gene maps to chromosome 6q13-15 and its messenger RNA has a large 3' untranslated region containing several AUUUA repeats. SH3BGRL2 codes for a protein of 107 amino acids, which, like SH3BGRL and SH3BGRL3 proteins, is highly homologous to the N-terminal region of the SH3BGR protein and appears to be related to Glutaredoxins and to PKC-interacting cousin of thioredoxin homology domain. We propose that the identification of SH3BGRL2 establishes a novel family of human genes, coding for highly conserved small proteins belonging to Thioredoxin-like protein Superfamily.
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PMID:The identification of a novel human homologue of the SH3 binding glutamic acid-rich (SH3BGR) gene establishes a new family of highly conserved small proteins related to Thioredoxin Superfamily. 1209 96

We report on a patient with a full monosomy 21 (FM21) prenatally diagnosed in cord fetal blood, and subsequently confirmed in other tissues. Subtle chromosomal translocations of chromosome 21, were ruled-out by FISH using both painting and 21q telomeric probes. Microsatellites analysis demonstrated the paternal origin of the single chromosome. The propositus showed at 32 weeks of gestation a severe intrauterine growth retardation and microcephaly. He was born with multiple congenital malformations, hypotonia, microcephaly, bilateral microphthalmia (more severe on the left), facial dysmorphism, agenesis of the external auditory meatus, redundant skin in the neck, narrow chest, flat scrotum, cryptorchydism, hypospadias, micropene, camptodactyly, nail hypoplasia, and abnormal palmar and plantar creases. The patient died in the first day of life. At necropsy, micrencephaly, semilobar holoprosencephaly, polimicrogyria, ocular abnormalities, skeletal anomalies, congenital heart disease, and agenesis of right kidney were also observed. To our best knowledge, this case is one of the most completely patient studied with FM21.
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PMID:A prenatally diagnosed patient with full monosomy 21: ultrasound, cytogenetic, clinical, molecular, and necropsy findings. 1510 21

We report here a patient with features of Down syndrome and tetralogy of Fallot who had a 21q22 duplication. The extent of the duplication was defined using fluorescent hybridization probes that map to the critical region on chromosome 21. Included within the interval was the cell adhesion molecule DSCAM but not the collagen COL6A1. The present case provides further support to the concept that there exists Down syndrome-associated congenital heart disease gene(s) on chromosome 21q22 and that over-expression of DSCAM may contribute to the cardiac defects of Down syndrome.
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PMID:Refining chromosomal region critical for Down syndrome-related heart defects with a case of cryptic 21q22.2 duplication. 1590 34

Type XVIII collagen is a multidomain protein that contains cleavable C-terminal NC1 and endostatin fragments, which have been shown to either induce or inhibit cell migration. Endostatin is being intensely studied because of its anti-angiogenic activity. Three variants of type XVIII collagen have been reported to be distributed in epithelial and endothelial basement membranes in a tissue-specific manner. The single gene encoding collagen XVIII is on chromosome 21 within the region associated with the congenital heart disease phenotype observed in Down's syndrome. In this study, we investigated the expression pattern of collagen XVIII in embryonic mouse hearts during formation of the atrioventricular (AV) valves. We found that collagen XVIII is localized not only in various basement membranes but is also highly expressed throughout the connective tissue core of the endocardial cushions and forming AV valve leaflets. It was closely associated with the epithelial-mesenchymal transformation of endothelial cells into mesenchymal cushion tissue cells and was localized around these cells as they migrated into the cardiac jelly to form the initial connective tissue elements of the valve leaflets. However, after embryonic day 17.5 collagen XVIII expression decreased rapidly in the connective tissue and thereafter remained detectable only in the basement membranes of the endothelial layer covering the leaflets. The staining pattern observed within the AV endocardial cushions suggests that collagen XVIII may have a role in cardiac valve morphogenesis. These results may help us to better understand normal heart development and the aberrant mechanisms that cause cardiac malformations in Down's syndrome.
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PMID:Collagen XVIII/endostatin is associated with the epithelial-mesenchymal transformation in the atrioventricular valves during cardiac development. 1617 Jul 84

A new mouse model of Down syndrome (DS) carries a copy of human chromosome 21 (Hsa21), in addition to a full complement of mouse chromosomes. In terms of the number of trisomic genes represented, this model, known as 'Tc1', is closer to the genetic background of DS than any previous model. The Tc1 model not only recapitulates several of the DS features present in other mouse models but also exhibits heart defects that are similar to those that make trisomy 21 the leading cause of congenital heart disease in humans. Many cells in adult Tc1 mice show mosaicism - that is, the Hsa21 is lost from some cells during development - increasing the complexity of analyses using this model. Tc1 mice provide a powerful tool for investigation of the pathogenesis of trisomy 21, and a platform for analysis of similarities and differences in the evolution of gene regulation.
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PMID:Down syndrome mouse models are looking up. 1667 59

The most common genetic disorder Down syndrome (DS) displays various developmental defects including mental retardation, learning and memory deficit, the early onset of Alzheimer's disease (AD), congenital heart disease, and craniofacial abnormalities. Those characteristics result from the extra-genes located in the specific region called nDown syndrome critical region (DSCR)' in human chromosome 21. In this review, we summarized the recent findings of the DYRK1A and RCAN1 genes, which are located on DSCR and thought to be closely associated with the typical features of DS patients, and their implication to the pathogenesis of neural defects in DS. DYRK1A phosphorylates several transcriptional factors, such as CREB and NFAT, endocytic complex proteins, and AD-linked gene products. Meanwhile, RCAN1 is an endogenous inhibitor of calcineurin A, and its unbalanced activity is thought to cause major neuronal and/or non-neuronal malfunction in DS and AD. Interestingly, they both contribute to the learning and memory deficit, altered synaptic plasticity, impaired cell cycle regulation, and AD-like neuropathology in DS. By understanding their biochemical, functional and physiological roles, we hope to get important molecular basis of DS pathology, which would consequently lead to the basis to develop the possible therapeutic tools for the neural defects in DS. [BMB reports 2009; 42(1): 6-15].
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PMID:Two key genes closely implicated with the neuropathological characteristics in Down syndrome: DYRK1A and RCAN1. 1919 87


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