Feasibility of a cost-effective approach to evaluate short tandem repeat markers suitable for chimerism follow-up.
ABSTRACT Precise chimerism monitoring is important for the prediction of the success of allogeneic bone marrow transplantation (BMT). Most of the current procedures employed for chimerism follow-up with short tandem repeat (STR) markers are either time-consuming, labor-intensive, or use expensive assays, making it burdensome to perform large-scale studies of transplanted patients.
To set-up a simple nonradioactive method to investigate a set of STR markers that could be used in the evaluation of chimerism status after allogeneic BMT.
Six dinucleotide STRs (D2S123, D5S107, CRTL1, D7S500, D11S1356, and TP53) were analyzed by touchdown (TD)-PCR followed by medium size non-denaturing polyacrylamide gel electrophoresis and silver staining. The sensitivity of the approach was evaluated by dilution competition assays. Peripheral blood samples were taken from a group of 50 healthy Argentinean donors, two transplanted patients, and their respective bone marrow donors. Buccal mucosa samples were also obtained from the BMT recipients.
Four markers, D2S123, D7S500, D11S1356, and TP53, presented the highest heterozygosities (0.67-0.88) under our experimental system. A sensitivity of 0.8-1.6% for chimerism detection was consistently found for the different STR. The usefulness of these STR in chimerism analysis was illustrated with the screening of related siblings analyzing two transplanted patients with persistent mixed chimerism, which were previously studied by fluorescence in situ hybridization (FISH). Similar proportions of mixed chimerism were obtained with STR analysis compared with those estimated by FISH.
To our knowledge, this was the first study of mixed chimerism using TD-PCR to achieve a highly specific STR amplification. This approach allows simple and accurate chimerism quantification because it avoids slippage of Taq polymerase on repeat stretches and prevents the differential amplification of the shorter allele. STR heterozygosities and the high level of sensitivity of this method demonstrated that this approach is not only very informative in this population, but is also rapid (taking less than 14 hours) and cost-efficient.
The data confirms that this method is a useful tool applicable to routine large-scale STR genotyping and mixed chimerism analysis in low-complexity laboratories worldwide.
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ABSTRACT: Loss of heterozygosity at the TP53 locus occurs frequently in many types of cancer and requires polymorphic markers for detection. Several polymorphisms at the TP53 locus have been described previously, and polymerase chain reaction (PCR)-based assays have been developed to detect these polymorphisms. However, these polymorphisms have relatively low levels of heterozygosity and are often uninformative. We report here the detection of loss of heterozygosity at the TP53 locus in various human cancers by using a highly informative dinucleotide repeat polymorphism.Genes Chromosomes and Cancer 08/1992; 5(1):89-90. · 3.55 Impact Factor
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ABSTRACT: The great increase in successful linkage studies in a number of higher eukaryotes during recent years has essentially resulted from major improvements in reference genetic linkage maps, which at present consist of short tandem repeat polymorphisms of simple sequences or microsatellites. We report here the last version of the Généthon human linkage map. This map consists of 5,264 short tandem (AC/TG)n repeat polymorphisms with a mean heterozygosity of 70%. The map spans a sex-averaged genetic distance of 3,699 cM and comprises 2,335 positions, of which 2,032 could be ordered with an odds ratio of at least 1,000:1 against alternative orders. The average interval size is 1.6 cM; 59% of the map is covered by intervals of 2 cM at most and 1% remains in intervals above 10 cM.Nature 04/1996; 380(6570):152-4. · 38.60 Impact Factor
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