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)

DNA sequence polymorphisms (RFLPs) have been widely used as genetic markers for identification of the X chromosome that carries the mutation for Duchenne muscular dystrophy (DMD) in affected families, but serious limitations and pitfalls are associated with this approach [Darras et al., 1987]. The complementary DNA (cDNA) of the DMD gene has recently been isolated and shown to detect partial gene deletions in a large proportion of patients [Koenig et al., 1987]. Two prenatal studies are presented to illustrate how the unambiguous identification of deletion mutations by cDNA probes permits direct DNA-based diagnoses with high accuracy and in otherwise uninformative families. In a single proband family, DNA marker analysis had determined that the Xp21 chromosomal region present in the affected male was also carried by a male fetus in a subsequent pregnancy. Analysis of this family's DNA with probes covering the entire 14 kb cDNA revealed a small deletion in the affected male that was not present in the fetus nor in the mother. In the second family the fetus was a female deletion carrier identified by comparing intensities of restriction fragments. Since 1/3 of all DMD patients are thought to result from new mutations and most families have only single affected males, the cloned cDNA probes now available are likely to revolutionize DNA-based diagnostic studies in this disorder. More reliable, more rapid and less expensive than linkage studies with DNA polymorphisms, this method will be informative in the more than 50% of DMD/BMD cases that have deletion mutations.
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PMID:Direct method for prenatal diagnosis and carrier detection in Duchenne/Becker muscular dystrophy using the entire dystrophin cDNA. 289 93

A DNA marker C7, localised Xp21.1-Xp21.3, has been studied in kindreds segregating for Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). In DMD families four crossovers were observed in 38 informative meioses between C7 and the DMD locus (theta = 0.12, z max = +2.72). In BMD families no recombinants were observed in the 16 informative meioses studied. These data are consistent with the localisation of the mutations in these disorders being in the same region of Xp21. Studies in families also segregating for the DNA marker 754 support the previously reported physical order of these loci as X centromere-754-DMD-BMD-C7-X telomere. A recombination fraction of 0.11 (z max = +5.58) was found between DMD-754 by combining our previously published data with the data presented here. C7 and 754 thus provide good bridging markers for the diagnosis of DMD and BMD.
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PMID:Segregation analysis of a marker localised Xp21.2-Xp21.3 in Duchenne and Becker muscular dystrophy families. 299 31