Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012872 (DNA marker)
 929 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic factors contribute to heart disease. In this study, linkage analyses have been performed in a family that is predisposed to sudden death from cardiac arrhythmias, the long QT syndrome (LQT). A DNA marker at the Harvey ras-1 locus (H-ras-1) was linked to LQT with a logarithm of the likelihood ratio for linkage (lod score) of 16.44 at theta = 0, which confirms the genetic basis of this trait and localizes this gene to the short arm of chromosome 11. As no recombination was observed between LQT and H-ras-1, and there is a physiological rationale for its involvement in this disease, ras becomes a candidate for the disease locus.
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PMID:Linkage of a cardiac arrhythmia, the long QT syndrome, and the Harvey ras-1 gene. 831 39

The long-QT syndrome (LQT; Ward-Romano syndrome) is a cardiac disorder that is inherited as an autosomal dominant trait. Affected family members suffer from recurrent syncope and sudden death due to ventricular arrhythmias. Recently, we identified a DNA marker on the short arm of chromosome 11 (the Harvey ras-1 locus [H-ras-1]) that was completely linked to the LQT locus in one large family. In the study presented here, we performed linkage investigations on six new and unrelated families with LQT. The LQT locus was again completely linked to the H-ras-1 locus in all families examined, with a combined lod score of 5.25 at a recombination fraction of 0. This work confirms our previous assignment of the LQT locus to chromosome 11p and supports the hypothesis that LQT is genetically homogeneous. As no obligate recombinants were identified in either this or our previous study, the H-ras-1 protooncogene remains a candidate for the LQT disease gene. Identification of LQT families with locus homogeneity is an important step in the development of a refined genetic map of this locus and will help determine whether the H-ras-1 marker would be of general use for presymptomatic diagnosis of this potentially fatal, but treatable, disorder.
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PMID:Consistent linkage of the long-QT syndrome to the Harvey ras-1 locus on chromosome 11. 174 60

It is now widely accepted that human neoplasms arise as a result of a sequence of mutations affecting the structure of genes involved in growth control. In humans, indirect measurements based on age dependent tumor incidence predict that, on average, the accumulation of 5 to 6 different steps is needed to initiate tumor formation. These mutations do not appear to be random, in that certain neoplasms show prediction for structural aberrations in specific genes. In thyroid tumors, some of gene abnormalities were found. The point mutations of ras oncogenes, predominantly H-ras codon 12, are found in 20-25% of follicular adenomas and papillary carcinomas. Recently, the gene rearrangements of the oncogenes trk and ret were identified in the DNA from papillary carcinomas. About 25% of papillary carcinomas contained an introchromosomal (10q) gene rearrangement involving the tyrosine kinase domain of the ret oncogene with an unknown amino-terminal sequence. The mutations of trk and/or ret were not observed in other thyroid neoplastic phenotypes. In medullary thyroid carcinoma, which is a tumor of the parafollicular, calcitonin-secreting C cell of the thyroid, approximately 20% of patients have autosomal dominant inherited forms. Germ line abnormalities on chromosome 10 are linked to at least one type of genetic medullary thyroid carcinoma (MEN type 2a). In the present time, the person who has the abnormality of gene causing MEN type 2a is able to detect by using DNA marker before the onset of tumor.
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PMID:[Thyroid carcinoma]. 198 98

Molecular genetic studies of tumor-specific allele loss, originally associated primarily with research regarding childhood hereditary cancers such as retinoblastoma and Wilms' tumors, only lately have been recognized as a relatively fast and fruitful way of locating cancer genes on human chromosomes. To date, over 25 different cancers have been tied to a gene (or genes) on a specific chromosome when this method has been used. During the past year alone, this approach has permitted detection of three genes involved in either hereditary or sporadic colorectal cancers. These three genes, located on chromosomes 5q, 17p, and 18q, are believed to belong to the newly described tumor suppressor (or growth suppressor) gene class, whose effects are opposite those of activated cellular oncogenes, which promote uncontrolled cell growth. Present studies, however, have not shown losses of any of these tumor suppressor genes to be correlated with the presence of activated ras genes in colorectal adenomas or carcinomas. During progression from adenoma to carcinoma, ras gene mutations and 5q allelic deletions are likely to be earlier events, whereas allelic losses from chromosomes 18q and 17p seem to occur more often in advanced tumors. Involvement of the genes on 5q (FAP) and 18q (Lynch syndrome II) in hereditary colon cancer syndromes is supported by linkage studies, but their respective roles (as well as that of the gene on 17p) in familial and sporadic colorectal cancer remain to be precisely defined. Probable isolation of these three genes by molecular cloning within the next few years will help elucidate their specific biologic functions. It will also permit early detection, and thus prevention, of some familial colon cancers (such as FAP), and possibly allow DNA marker-based separation of different colon cancer subtypes of similar histologic appearance.
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PMID:Molecular genetic studies of colon cancer. 264 66

Romano-Ward syndrome is an autosomal dominant trait disease, which is characterized by QT prolongation and normal hearings and shows predisposal to sudden death from cardiac arrhythmia. Recently, Keating et al. reported that Harvey ras-1 locus (H-ras-1) was closely linked to long QT syndrome (LQTS), being located on the short arm of chromosome 11. In this study we have examined a three-generation Japanese family whose members had recurrent fainting with prolongation of the QT interval on electrocardiogram. Using the H-ras-1 probe as DNA marker, we could not determine that the H-ras-1 gene was linked to LQTS. LQTS seems to be a genetically heterogeneous disease. Further study is needed to clarify the chromosomal location of the LQTS.
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PMID:[Linkage analysis in a Japanese long QT syndrome family]. 848 55

The familial long-QT syndrome (LQTS) is an infrequently occurring disorder in which affected family members have QT prolongation on the ECG, often associated with recurrent syncope and fatal ventricular arrhythmias. Autosomal recessive and autosomal dominant modes of inheritance were suggested by the pattern of occurrence of this disorder in the first reported LQTS families. Statistical genetic analysis (segregation analysis) has substantiated a major gene effect on QTc length in two large pedigrees. Gene linkage studies have uncovered tight linkage between a DNA marker at the Harvey ras-1 locus on chromosome 11 and LQTS in one large pedigree, substantiating a genetic basis of this disorder.
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PMID:The long-QT syndrome Genetic considerations. 2123 64