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)

Three Down syndrome patients for whom karyotypic analysis showed a "mirror" (reverse tandem) duplication of chromosome 21 were studied by phenotypic, cytogenetic, and molecular methods. On high-resolution R-banding analysis performed in two cases, the size of the fusion 21q22.3 band was apparently less than twice the size of the normal 21q22.3, suggesting a partial deletion of distal 21q. The evaluation of eight chromosome 21 single-copy sequences of the 21q22 region--namely, SOD1, D21S15, D21S42, CRYA1, PFKL, CD18, COL6A1, and S100B--by a slot blot method showed in all three cases a partial deletion of 21q22.3 and partial monosomy. The translocation breakpoints were different in each patient, and in two cases the rearranged chromosome was found to be asymmetrical. The molecular definition of the monosomy 21 in each patient was, respectively, COL6A1-S100B, CD18-S100B, and PFKL-S100B. DNA polymorphism analysis indicated in all cases a homozygosity of the duplicated material. The duplicated region was maternal in two patients and paternal in one patient. These data suggest that the reverse tandem chromosomes did not result from a telomeric fusion between chromosomes 21 but from a translocation between sister chromatids. The phenotypes of these patients did not differ significantly from that of individuals with full trisomy 21, except in one case with large ears with an unfolded helix. The fact that monosomy of distal 21q22.3 in these patients resulted in a phenotype very similar to Down syndrome suggests that the duplication of the genes located in this part of chromosome 21 is not necessary for the pathogenesis of the Down syndrome features observed in these patients, including most of the facial and hand features, muscular hypotonia, cardiopathy of the Fallot tetralogy type, and part of the mental retardation.
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PMID:No significant effect of monosomy for distal 21q22.3 on the Down syndrome phenotype in "mirror" duplications of chromosome 21. 146 8

A Chinese male infant with arthrogryposis multiplex congenita (AMC), ventricular and atrial septal defects, and Werdnig-Hoffmann disease (WHD) had deletions of the telomeric copy of the survival motor neuron (SMN(T)) and neuronal apoptosis inhibitory protein genes. Children with AMC or congenital heart disease, or both, and motor neuron disease should undergo testing for SMN(T) deletion. This rare association further illustrates the variable phenotypic expressions of WHD.
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PMID:Large-scale deletions in a Chinese infant associated with a variant form of Werdnig-Hoffmann disease. 974 47

The DiGeorge syndrome (DGS) is a developmental defect of the third and fourth pharyngeal pouches, which is associated with congenital heart defects, hypoparathyroidism, cell-mediated immunodeficiency, velo-pharyngeal insufficiency and craniofacial dysmorphism. The aetiological factor in a great majority of DGS cases is monosomy for the chromosomal region 22q11. To analyze DGS at the molecular level, a new molecular probe (DGCR680) encompassing the ADU balanced translocation breakpoint was prepared. When 13 Korean patients with DGS-type congenital heart disease were analyzed with this probe, 9 turned out to have a deletion at this locus, and all of them except one exhibited a typical facial dysmorphism associated DGS. Though only 9 independent patients were detected to have a deletion at the locus using the commercial probe N25 (D22S75), which maps at about 160 kb from the ADU breakpoint to the telomeric end, results from fluorescence in situ hybridization revealed a deletion in all cases tested at this locus. Two patients who had a deletion at the locus D22S75 but not at DGCR680 did not exhibit any DGS-type facial abnormalities. This result implies that the 680 bp probe covering the ADU translocation breakpoint might be a candidate for a molecular marker that can distinguish a specific phenotype, such as facial features associated with the DiGeorge syndrome. This study also suggested that systematic approaches with several small DNA probes along the DGCR could help to dissect the complex phenotypes associated with the DiGeorge syndrome, such as cardiac defects, abnormal faces, thymic hypoplasia, cleft palate, and hypocalcemia, etc.
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PMID:Molecular genetic analysis of the DiGeorge syndrome among Korean patients with congenital heart disease. 1010 75

Hemochromatosis is a recessive disorder of iron metabolism characterized by progressive iron loading of parenchymal organs, which accounts for clinical complications such as cirrhosis, diabetes mellitus, cardiopathy, endocrine dysfunctions and arthropathy. Clinical complications, which usually develop after the third or fourth decade of life, can be fatal but may be prevented by phlebotomy if iron excess is detected at a very early stage. The hemochromatosis gene (HFE), located 4.5 megabases telomeric to the HLA-A locus, encodes an HLA class I like protein and two missense mutations, C282Y and H63D in complete disequilibrium have been identified within this gene. Due to its high frequency in the general population, the involvement of H63D in the pathogenesis of the disease remains controversial, and it might correspond to a minor mutation. Conversely, the C282Y mutation is tightly linked to the disease, as it accounts for 80 to 100% of the hemochromatosis cases in Northern Europe. The lower frequency observed, in the patients, in Italy and South of France led to imagine either the implication of other mutations or of other genes. The C282Y mutation is absent in Asia and Africa and is present in the general population with a decreasing gradient of frequency from Northern to Southern Europe. The prevalence of the disease was usually estimated to be 3% but the observed frequency of the C282Y homozygotes is 5% in our breton population raising the question of the penetrance of the disease, and consequently the use of the genotypic test for its systematic screening. As HFE encodes a membrane protein similar to HLA class I protein, its contribution to iron overload is not obvious. The normal protein is predicted to to be expressed at the cell surface in association with beta 2-microglobulin, a localization for which C282Y is critical as it disrupts this association. This protein has also been shown to form a stable complex with the transferrin receptor leading to a decreased affinity for transferrin. A better knowledge of its function will help to decipher iron and different metal-ions metabolism. Although the exact role of the HFE protein is unknown, the genotypic test allows the clinicians to ascertain their diagnosis and genetic counselling.
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PMID:[Molecular genetics of hemochromatosis]. 1052 Apr 11

During normal ageing, the gradual loss of telomeric DNA in dividing somatic cells can contribute to replicative senescence, apoptosis, or neoplastic transformation. In the genetic disorder dyskeratosis congenita, telomere shortening is accelerated, and patients have premature onset of many age-related diseases and early death. We aimed to assess an association between telomere length and mortality in 143 normal unrelated individuals over the age of 60 years. Those with shorter telomeres in blood DNA had poorer survival, attributable in part to a 3.18-fold higher mortality rate from heart disease (95% CI 1(.)36-7.45, p=0.0079), and an 8.54-fold higher mortality rate from infectious disease (1.52-47.9, p=0.015). These results lend support to the hypothesis that telomere shortening in human beings contributes to mortality in many age-related diseases.
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PMID:Association between telomere length in blood and mortality in people aged 60 years or older. 1268 62

Uniparental disomy for a number of human chromosomes is associated with clinical abnormalities. We report a child with a complex chromosomal rearrangement involving chromosome 20 (45,XY,psu dic (20;20)(p13;p13)) and paternal uniparental isodisomy for chromosome 20 in peripheral blood and bone marrow. This patient had multiple congenital abnormalities including microtia/anotia, micrencephaly, congenital heart disease, neuronal subependymal heterotopias, and colonic agangliosis. Molecular studies on DNA from peripheral blood demonstrated paternal uniparental inheritance of chromosome 20. However, fibroblasts demonstrated a mosaic karyotype, with one cell line having 45 chromosomes, including the pseudodicentric chromosome 20 (75% of cells), and a second cell line having 46 chromosomes, including the pseudodicentric chromosome 20, and a normal chromosome 20 (trisomy 20) (25% of cells). FISH experiments using a sub-telomeric probe that maps approximately 120 kb from the 20p telomere, showed that both copies of these sequences were present on the rearranged chromosome, consistent with deletion of a very small interval. This leads us to suggest that in addition to trisomy 20 mosaicism, paternal uniparental disomy for chromosome 20 could contribute to his clinical phenotype.
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PMID:Mosaic paternal uniparental (iso)disomy for chromosome 20 associated with multiple anomalies. 1470

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

Telomere length is linked to age-associated diseases, with shorter telomeres in blood associated with an increased probability of mortality from infection or heart disease. Little is known about how human telomere length is regulated despite convincing data from twins that telomere length is largely heritable, uniform in various tissues during development until birth and variable between individuals. As sperm cells show increasing telomere length with age, we investigated whether age of fathers at conception correlated with telomere length of their offspring. Telomere length in blood from 125 random subjects was shown to be positively associated with paternal age (+22 bp yr -1, 95% confidence interval 5.2-38.3, P = 0.010), and paternal age was calculated to affect telomere length by up to 20% of average telomere length per generation. Males lose telomeric sequence faster than females (31 bp yr -1, 17.6-43.8, P < 0.0001 vs. 14 bp yr -1, 3.5-24.8, P < 0.01) and the rate of telomere loss slows throughout the human lifespan. These data indicate that paternal age plays a role in the vertical transmission of telomere length and may contribute significantly to the variability of telomere length seen in the human population, particularly if effects are cumulative through generations.
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PMID:Paternal age is positively linked to telomere length of children. 1577 13

Telomerase is active in early embryonic and fetal development but is down-regulated in all human somatic tissues before birth. Since telomerase is virtually absent or only transiently active in normal somatic cells throughout postnatal life, telomere length gradually decreases as a function of age in most human tissues. Although telomerase repression likely evolved as a tumor suppressor mechanism, a growing body of evidence from epidemiology and genetic studies point to a role of telomerase repression and short telomeres in a broad spectrum of diseases: (a) Humans with shorter than average telomere length are at increased risk of dying from heart disease, stroke, or infection; (b) Patients with Dyskeratosis congenita are born with shortened telomeres due to mutations in telomerase components, suffer from a variety of proliferative tissue disorders, and typically die early of bone marrow failure; and (c) Individuals with long-term chronic stress or infections have accelerated telomere shortening compared to age-matched counterparts. Telomerase activation may prove useful in the treatment of diseases associated with telomere loss. While human cells dividing in culture lose telomeric DNA and undergo changes that mirror certain age- or disease-associated changes in vivo, telomerase transduced cells have extended replicative capacities, increased resistance to stress, improved functional activities in vitro and in vivo, and no loss of differentiation capacity or growth control. In addition, telomerase transduction in vivo can prevent telomere dysfunction and cirrhotic changes in liver of telomerase knockout mice. Thus, pharmacological activation of telomerase has significant potential for the treatment of a broad spectrum of chronic or degenerative diseases.
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PMID:Telomerase therapeutics for degenerative diseases. 1597 74

Accumulation of cellular damage with advancing age leads to atherothrombosis and associated cardiovascular disease. Ageing is also characterized by shortening of the DNA component of telomeres, the specialized genetic segments located at the end of eukaryotic chromosomes that protect them from end-to-end fusions. By inducing genomic instability, replicative senescence and apoptosis, shortening of the telomeric DNA is thought to contribute to organismal ageing. In this Review, we discuss experimental and human studies that have linked telomeres and associated proteins to several factors which influence cardiovascular risk (eg, estrogens, oxidative stress, hypertension, diabetes, and psychological stress), as well as to neovascularization and the pathogenesis of atherosclerosis and heart disease. Two chief questions that remain unanswered are whether telomere shortening is cause or consequence of cardiovascular disease, and whether therapies targeting the telomere may find application in treating these disorders (eg, cell "telomerization" to engineer blood vessels of clinical value for bypass surgery, and to facilitate cell-based myocardial regeneration strategies). Given that most research to date has focused on the role of telomerase, it is also of up most importance to investigate whether alterations in additional telomere-associated proteins may contribute to the pathogenesis of cardiovascular disease.
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PMID:Telomere biology and cardiovascular disease. 1712 47


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