Determination of hematopoietic clonality by detection of multiple X-linked gene exonic polymorphic loci using transcription-based clonality assays / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the frequencies of heterozygosity in X-linked G6PD, P55, BTK, and FHL-1 gene exonic polymorphic loci among Chinese females and the value of determination of hematopoietic clonality by detection of these X-chromosome exonic polymorphisms based on X-chromosome inactivation patterns (XCIP)-transcription-based clonality assays (TCA).</p><p><b>METHODS</b>Genomic DNA was extracted from peripheral blood of 446 Chinese healthy females. Allele-specific PCR (ASPCR) or PCR-restriction enzyme digestion method was applied for detecting G6PD, P55, BTK and FHL-1 polymorphisms. Those heterozygotic loci were used as markers to examine the hematopoietic clonality of bone marrow mononuclear cells by TCA from essential thrombocythemia (ET) patients with JAK2V617F mutation and myelodysplastic syndrome (MDS) patients with abnormal karyotype.</p><p><b>RESULTS</b>Among the total 446 genomic DNA samples, the frequencies of heterozygosity in G6PD, P55, BTK and FHL-1 loci were 12.8%, 29.4%, 52.0% and 46.4%, respectively. About 81.4% of females were heterozygous at one or more loci. All 10 ET patients with JAK2V617F mutation and 2 MDS patients with abnormal karyotype, which were heterozygotic in either locus, had monoclonal/oligoclonal hematopoiesis.</p><p><b>CONCLUSION</b>Clonality detection based on X chromosome inactivation patterns-transcription based clonality assays is applicable to about 80% of Chinese females.</p>

Relationship between RAD51-G135C/XRCC3-C241T polymorphisms and development of acute myeloid leukemia with recurrent chromosome translocation / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between DNA homologous recombination (HR) repair genes RAD51-G135C/XRCC3-C241T polymorphisms and development of acute myeloid leukemia (AML) with recurrent chromosome translocation.</p><p><b>METHODS</b>Genomic DNA was extracted from bone marrow cells of 625 de novo AML patients and peripheral blood cells of 806 patient family members and 704 unrelated volunteers. Genotypes of RAD51-G135C and XRCC3-C241T were analyzed by PCR-RFLP. Cell lines with genotypes differed from XRCC3-C241T were selected and irradiated in vitro. The CBFβ-MYH11 fusion gene was detected by TaqMan real-time PCR.</p><p><b>RESULTS</b>The XRCC3-C241T variant (C/T + T/T) showed 6.22-fold and 6.99-fold increase in the risk of developing the AML with inv(16)/t(16;16)/CBFβ-MYH11 as compared with the volunteer and family member controls respectively; the RAD51-G135C homozygote-type (C/C) variant showed 0.87-fold (P = 0.010) and 1.15-fold (P = 0.001) respectively increase in the risk of this subtype AML. In the irradiated group, the CBFβ-MYH11 mRNA level in HL-60 cells was 59.49 times increased than that in KG1a cells. However, the RAD51-G135C and XRCC3-C241T variants had no correlations with the risk of development of t(15;17)/PML-RARα(+)AML, t(8;21)/AML1-ETO(+) AML and 11q23 AML subtypes.</p><p><b>CONCLUSION</b>The XRCC3-C241T variant and the RAD51-G135C homozygote-type significantly increase the risk of the development of AML with inv(16)/t(16;16)/CBFβ-MYH11.</p>

Study on NPM1 gene mutations in patients with primary myelodysplastic syndromes / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate NPM1 gene mutations in patients with primary myelodysplastic syndromes (MDS) and the clinical characteristics of patients with NPM1 mutants.</p><p><b>METHODS</b>Genomic DNA corresponding to exon 12 of NPM1 gene was amplified by polymerase chain reaction (PCR) in 232 patients with primary MDS. Identification of mutants was by direct sequencing and classification of mutation types by sequencing followed by plasmid cloning.</p><p><b>RESULTS</b>NPM1 mutants were found in 9 patients (3.9%). All the mutants were type A. As compared with those with NPM1 wild type, patients with the mutant were of lower ANC \[0.60 (0.12 - 2.91) × 10(9)/L vs 1.02 (0 - 10.23) × 10(9)/L, P = 0.046\], higher blast percent in bone marrow \[0.050 (0 - 0.090) vs 0.025 (0 - 0.190), P = 0.035\], decreased BFU-E \[0 (0 - 0)/10(5) BMMNC vs 6 (0 - 40)/10(5) BMMNC, P = 0.038\] and increased serum vitamin B(12) \[936.40 (373.80 - 2400.00) pmol/L vs 557.85 (17.00 - 3032.10) pmol/L, P = 0.045\] The chromosomal karyotypes of patients with NPM1 mutant were predominantly normal.</p><p><b>CONCLUSION</b>MDS patients with NPM1 gene mutations have some unique clinical and laboratory features. The results give new hint for the pathogenesis of MDS development and progression.</p>