Methylenetetrahydrofolate reductase [MTHFR] genotype association with the risk of chronic myelogenous leukemia

The metabolism of folate is essential in DNA synthesis, and polymorphisms of genes involved in this metabolism have been implicated in many types of cancer. One such gene is the Methylenetetrahydrofolate Reductase [MTHFR] gene, which encodes an enzyme that converts folate to a methyl donor used for DNA methylation. In this report, we studied the association between the different genotypes of the two most common MTHFR polymophisms, C677T and A1298C, and the risk of Chronic Myelogenous Leukemia [CML]. For this purpose, 149 of previously diagnosed CML patients and 170 normal controls were examined using PCR followed by Restriction Fragment Length Polymorphism [RFLP]. Results showed that the frequency of the C677T TT homozygous mutant genotype in patients with CML was significantly higher compared to controls [OR - 2.84, 95% CI: 1.24-6.50, .P-value - 0.014]. No such association was shown for the heterozygous C677T CT genotype [OR = 1.52, 95% CI: 0.95-2.41, P-value - 0.081]. As for the A1298C genotypes, a statistically significant higher frequency of the mutant homozygous genotype 1298CC was also detected in CML patients compared to the control group [OR - 2.18, 95% CI: 1.01-4.69, P-value - 0.046]. No such statistical significance was demonstrable for the heterozygote genotype 1298AC [OR = 1.08, 95% CI: 0.68-1.73, P-value = 0.743]. This is the first report to suggest that both mutated MTHFR genotypes, specifically the homozygous 677TT and 1298CC polymorphisms, can be associated with a higher risk of developing CML

Highly Sensitive Multiplex RT-PCR System for the Detection of all Common BCR-ABL Transcripts Associated with Different Leukemias

After the recent characterization of leukemia-specific DNA rearrangements, molecular methods have become primary tools for the diagnosis and monitoring of many hematological malignancies, due to their superior sensitivity and accuracy over other conventional methods. The BCR-ABL fusion transcripts resulting from the t[9; 22] translocation are distinct hallmarks of Philadelphia chromosome positive [Ph[+]] leukemias. There are clear associations between different isoforms of the BCR-ABL fusion protein and specific phenotypes of these leukemias. Each isoform also has a significant prognostic value and can be a critical indicator of the clinical outcome. In this study we have adopted, with modifications, a highly sensitive and specific method to screen simultaneously for the most frequent BCR-ABL fusion transcripts, namely, p210 [b3a2/b2a2], p190 [ela2] and p230 [e19a2]. A multiplex reverse-transcriptase polymerase chain reaction [RT-PCR] protocol with nested primer strategy for each of the above fusion transcripts was carefully optimized. RNA integrity, cDNA synthesis and PCR amplification were checked using internal control primers for the normal untranslocated BCR gene. Over 100 clinical samples were collected from hospitals in Amman between 2003 and 2005. This system was applied successfully on 100 clinical samples previously diagnosed as chronic myelogenous leukemia [CML] and acute lymphocytic leukemia [ALL]. RNA extracts from established leukemic cell lines carrying the translocations of interest were used as external positive controls. Representative PCR products were sequenced to verify the specificity of the amplification system. Our multiplexed nested RT-PCR assay provides a sensitive, accurate, time-saving and cost-effective diagnostic tool for the diagnosis and monitoring of patients with Ph [+] leukemias