[Correlations Between AML1-ETO Fusion Gene and Clinical Features of Acute Myeloid Leukemia in Sichuan.]

OBJECTIVES: To determine the correlations between AML1-ETO fusion gene and clinical characteristics of patients with AML,and its association with the prognosis of AML-M2. METHODS: Medical records of 94 AML-M2 cases with positive AML1-ETO fusion gene and 51 AML-M2 cases with negative AML1-ETO gene were retrospective reviewed.Their clinical characteristics,treatment responses and prognostic outcomes were compared. RESULTS: No significant differences in the clinical symptoms,predominantly anemia,fever and hemorrhage,were found between the AML1-ETO fusion gene positive and negative AML-M2 (P>0.05).However,lower levels of red blood cell (RBC) and platelet (PLT),and higher levels of ratio of grain to red,percentage of bone marrow granulocyte (NC),CD34,human leukocyte antigen DR (HLA-DR),CD56 and CD19 were found in those with positive AML1-ETO fusion gene (P<0.05).The efficacy of treatments and survival curves showed no significant differences between the two groups (P>0.05).CD56 and original percentage of bone marrow granulocyte were predictors of poor long-term survival.Complete remission was the only predictor of better long-term survival. CONCLUSIONS: AML1-ETO fusion gene is neither associated with clinical symptoms,nor with survival and long term prognosis in Sichuan.As many factors affect the efficacy of treatments and prognosis of AML-M2,stratified analysis is needed to determine the role of AML1-ETO.

[FLT3 Gene Expression and Its Clinical Significance in Acute Myeloid Leukemia.]

OBJECTIVES: To determine the correlation between fms-like tyrosine kinase 3 gene (FLT3) expression and FLT3-internal tandem duplication (ITD) mutations in acute myeloid leukemia patients,and the association between expression of FLT3 gene and clinical and laboratory features of patients. METHODS: The expression of FLT3 mRNA in bone marrow (BM) leukemic cells of 128 acute myeloid leukemia (AML) patients was measured by real-time PCR.The patients were divided into two groups using the 35% FLT3 expression as a cut-off point.The associations between the expression level of FLT3 and clinical and laboratory features of patients were analyzed. RESULTS: The patients had a FLT3 gene expression level of 0.01-180.68 (mean 14.65) at the initial diagnosis,with AML-M1 the most expressed and AML-M6 the least expressed,but without statistical significance.The patients with a high level of FLT3 gene expression had higher peripheral blood white blood cell count (WBC) (P<0.01) and were more likely to become anemic and febrile (P<0.05).WBC [regression coefficient (B)=1.508,odds ratio (OR)=4.518,95% confidence interval(CI):1.465-13.390,P=0.009] and anemia (B=2.142,OR=8.513,95%CI:3.201-22.644,P<0.001)were predictors of higher expression of FLT3.The patients with high levels of FLT3 gene expression had lower complete remission rate (32/83),compared with those (36/44) with low levels of FLT3 gene expression (P<0.05).The Cox regression analysis showed that the patients with higher levels of FLT3 gene expression had a higher risk of death (B=1.338, relative risk=3.810, 95%CI:1.820-7.947,P<0.001).The Kaplan-Meier analysis showed that the patients with higher levels of FLT3 gene expression had lower survival time (56.63%) than those with lower levels of FLT3 expression (70.45%,P<0.05). CONCLUSIONS: FLT3 gene has adverse impacts on complete remission of AML.High expression of FLT3 gene is associated with poor prognosis of patients with AML.

[Gene Mutation Spectrum Analysis of 170 Patients with Duchenne/Bayesian Muscular Dystrophy in Southwest of China].

OBJECTIVE: To determine gene variations and genotype-phenotype correlations in Duchenne/Bayesian muscular mystrophy (DMD/BMD) patients, and the association between dystrophin gene polymorphisms and clinical phenotype. METHODS: Multiplex ligation-dependent probe amplification (MLPA) was adopted to detect dystrophin gene variations in 170 patients. Sanger sequencing was performed in 3 cases with decreased peaks in MLPA results. RESULTS: The MLPA detected 72.94% mutations in dystrophin gene, including 62.35% (106/170) deletions, 8.82% (15/170) duplications, and 1.76% (3/170) point mutations. 64 different types of mutations were found. 75.47% of deletions occurred in the range from exon 44 to 55. Most 5' breakpoints of exonic variations were located in 2 hotspots (major hotspot: intron 43-55; minor hotspot: intron 1-20), which is different from findings of other studies. Genotype-phenotype analysis showed that the severity of DMD/BMD was associated with frame shift mutation (r = 0.640, P < 0.001) but not with deletions or duplications. CONCLUSION: Deletions and duplications of exon compose the main type of dystrophin gene mutations. DMD/BMD is associated with frame shift mutation.

[Genetic Polymorphisms in Wnt Signaling Pathway and Acute Leukemia].

OBJECTIVE: To determine the impacts of Wnt signaling pathway products-polymorphisms of rs4135385, rs11079571 and rs7832767 located in ß-catenin gene (CTNNB1), Axin gene (AXIN2), and secreted frizzled-related protein gene (SFRP1) on the risk and treatment outcomes of acute leukemia. METHODS: Bone marrows (volume 1-1. 5 mL) were collected from 372 untreated patients with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL), and peripheral blood samples (2. 0 mL) were obtained from 401 healthy controls for the purpose of total DNA extraction. Polymorphisms of rs4135385, rs11079571 and rs7832767 located in CTNNB1, AXIN2 and SFRP1 were genotyped with high-resolution melting method (HRM). Chi-square analyses were performed to compare the genotype and allele distributions of the three single nucleotides (SNPs) between the leukemia patients and healthy controls. Single factor variance tests were performed to compare the differences in clinical features among different genotype groups. Complete remission (CR) rates after induction chemotherapy were also compared between different genotype groups using Chi-square tests. RESULTS: No significant differences were found beiween the leukemia patients and healthy controls in the frequencies of alleles and genotypes of CTNNB1 rs4135385, SFRP1 rs7832767 polymorphisms. Those with A allele in AXIN2 rs11079571 polymorphism was less likely to have acute myelomonocytic/monocytic leukemia than those with G allele (P = 0. 016, OR=0. 677, 95%CI:0. 439-0. 930). Acute bead monocyte/mononuclear cell leukemia (AML-M4/5)patients with AA genotype presented higher platelet count (P = 0. 040), and higher complete remission rate after chemotherapy (P = 0. 040), compared with the patients with AG and GG genotypes. CONCLUSION: AML-M4/5 patients have less frequency of A allele in AXIN2 rs11079571 polymorphism than healthy controls. Patients carrying A allele have higher platelet counts and higher sensitivity to chemotherapy.

[Correlation between JAK2-V617F mutations and variation of peripheral blood cells among BCR/ABL-negative MPD patients].

OBJECTIVE: To assess the correlation between JAK2-V617F mutation and complete blood counts among patients with BCR/ABL-negative myeloproliferative diseases (MPD). METHODS: One hundred and ninety one patients were recruited. Retrospectively, their laboratory data were analyzed for the counts of red blood cells (RBC), white blood cells (WBC) and platelets (PLT). And the incidence of JAK2-V617F mutation was determined. RESULTS: There was significant difference in the incidence of JAK2-V617F mutation between patients with different cell counts (P< 0.01). The incidence of JAK2-V617F mutation has increased with the counts of RBC and PLT, which was the highest (92.86%) among those featuring simultaneous increase in all three series. CONCLUSION: The incidence of JAK2-V617F mutation seems to be strongly associated with variation of peripheral blood cell counts among patients with BCR/ABL-negative MPD. Variation of peripheral blood cells, particularly RBC, may be correlated with the rate of JAK2-V617F mutation.

[DNA homology between methicillin-resistant Staphylococcus aureus strains isolated from the wounds caused by earthquake and those from patients from other areas during the same period].

OBJECTIVE: To investigate the DNA homology between the methicillin-resistant Staphylococcus aureus (MRSA) isolated from the wounds caused by earthquake and those from the patients from non-earthquake-stricken areas. METHODS: Five MRSA isolates were obtained from the wounds caused by earthquake of 5 in-patients admitted into the West China Hospital, and 6 MRSA isolates were obtained from the inpatient of the same hospital during the same period. DNA fingerprint alas was obtained by repetitive extragenic palindromic sequence-based PCR (Rep-PCR) and homolog analysis was conducted with the help of Rep-based DiversiLab Microbial Typing system. RESULTS: Five different patterns (A-E) were found among the 11 MRSA strains. The 5 strains isolated from the wounds caused by earthquake included subtype A (n = 1), subtype B (n = 2), subtype C (n = 1), and subtype E (n = 1). And the 6 stains isolated from the patient that come from non-earthquake-stricken areas included A (n = 3), subtype B (n = 1), subtype C (n = 1), and subtype D (n = 1). CONCLUSION: The MRSA stains isolated from the wounds caused by earthquake are highly homologous with those isolated from the patient from non-disastrous areas during the same period.

[Genetic types of three community-acquired methicillin-resistant Staphylococcus aureus isolates].

OBJECTIVE: To investigate the genetic features of the community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) prevalent in West China. METHODS: Three CA-MRSA isolates obtained in Chengdu, Sichuan, underwent SCCmec (Staphylococcal Cassette Chromosome mec) multi-PCR, Staphylococcal protein A (spa) typing and multi-locus sequence typing (MLST) method, and their Panton-Valentine leucocidin (PVL) gene was also detected. RESULTS: All 3 CA-MRSA isolates were positive of mecA gene (147 bp), and the other PCR product of 750 bp was confirmed to be type IVa SCCmec. Spa typing showed that the MRSA strains s29635 and s35301 were typed as t437, and the strain s19165 was typed as t008. MLST showed that the MRSA strains s29635 and s35301 were typed as ST59, and the strain s19165 was typed as ST8. The strains s19165 and s35301 were all positive for PVL gene, and the strain s29635 was negative for PVL gene. CONCLUSION: CA-MRSA clones ST8-t008 and ST59-t437 have been isolated in West China.

Influence of SCARB1 gene SNPs on serum lipid levels and susceptibility to coronary heart disease and cerebral infarction in a Chinese population.

The SCARB1 gene encodes human scavenger receptor class B type I (SR-BI), the primary receptor for high-density lipoprotein (HDL)- cholesteryl ester uptake, and polymorphisms in this gene may influence SR-BI protein expression and serum lipid levels, modulating susceptibility to coronary heart disease (CHD) and cerebral infarction (CI). Therefore, we investigated the association between singlenucleotide polymorphisms (SNPs) in the SCARB1 gene and serum lipid levels as well as risk of CHD and CI in the Chinese Han population. Genotypes in 295 CHD patients, 302 CI patients and 312 healthy controls matched for age and gender were determined by high-resolution melting (HRM). Among the 5 SNPs investigated in this study, rs10846744 and rs2278986 were significantly associated with CHD risk. The frequency of the C allele for rs10846744 and that of the T allele for rs2278986 appeared to be significantly increased in the CHD group (OR: 1.416, 95%CI: 1.128-1.778, P=0.0058 and OR: 1.681, 95%CI: 1.327-2.130, P<0.0001, respectively). CHD patients with genotypes CC and CG for rs10846744 had a higher HDL-c level than those with genotype GG, and CHD patients with genotypes CC and CT for the rs2278986 SNP had a higher HDL-c level compared to those with the TT allele. The other 3 SNPs, rs5888, rs10744182 and rs838893, showed no significant association with serum lipid levels and CHD or CI risk in the Chinese population. The CCCTT and CCTTC haplotypes of rs5888, rs10846744, rs10744182, rs2278986 and rs838893 appear to significantly increase CHD risk, whereas the CGTTC, CCTCT and TGCTC haplotypes appear to significantly reduce risk. Overall, the CCTTC and TGTTC haplotypes acted as a significant risk for CI, with the CGCTC and CCCCT haplotypes conferring significantly reduced risk. These results suggest that SCARB1 gene polymorphisms may contribute to genetic susceptibility to CHD; in particular, the C allele of rs10846744 and the C allele of rs2278986 may serve as risk and protective factors for CHD, respectively.

Clinical significance of BCR-ABL fusion gene subtypes in chronic myelogenous and acute lymphoblastic leukemias.

BACKGROUND: Some reports have suggested that chronic myeloid leukemia (CML) patients have a higher prevalence of M-bcr than acute lymphoblastic leukemia (ALL) patients, which show a higher prevalence of m-bcr. However, the relationship between BCR-ABL subtypes and progression of CML and ALL remains unclear. MATERIALS AND METHODS: 354 CML chronic phase (CML-CP) patients, 26 CML blastic phase (CML-BP) patients and 72 ALL patients before treatment with BCR-ABL positive were recruited for blood routine examination and bone marrow smear cytology. Some 80 CML-CP and 32 ALL patients after imatinib (IM) treatment were followed-up for BCR-ABL relative concentrations detected after treatment for 3, 6 and 9 months and 1 year. RESULTS: Before treatment, CML-CP patients showed lower BCR-ABL relative concentrations with a higher proportion of M-bcr (42.7%) compared to CML-BP and ALL patients while ALL patients had a higher BCR-ABL relative concentration with high expression of m-bcr (51.4%). Patients with M-bcr demonstrated higher WBC counts than those with m-bcr and the mixed group and higher PLT counts were noted in the CML-CP and ALL groups. After imatinib (IM) treatment, patients with m-bcr showed higher BCR-ABL relative concentrations in both CML-CP and ALL groups. CONCLUSIONS: This study identified the BCR-ABL gene as an important factor in CML and ALL cases. The M-bcr subtype was associated more with CML while the m-bcr subtype was associated more with ALL. Patients with m-bcr seem to have a poorer response to IM in either CML or ALL patients compared to M-bcr patients.

Frequency distribution of single nucleotide polymorphisms in P-selectin gene in Chinese Tibetan and Han populations.

BACKGROUND: Chinese Tibetans have a series of distinctive physiological traits which enable them to tolerate the extreme environment of the Tibetan plateau. P-selectin gene has been proved to be highly polymorphic in Europeans and Americans. Nevertheless, studies on either the frequency distributions of single nucleotide polymorphisms (SNPs) or haplotype diversity and linkage disequilibrium of P-selectin gene in Chinese Tibetan population are still unavailable. METHODS: The frequency distributions of 3 SNPs in P-selectin gene promoter (-2123C/G, -1969A/G, -1817T/C) and 3 SNPs in exon region (Ser290Asn, Val599Leu, Thr715Pro) were investigated by real-time PCR and high-resolution melting method among 314 Chinese Tibetans and 328 age- and sex-matched Han people. RESULTS: The frequencies of the -2123G and -1817T alleles among the Tibetan population had no significant differences from those of the Han population. Among the Tibetan population, the G allele frequency of -1969A/G and Ser290Asn were both higher than those of the Han population. Val599Leu and Thr715Pro did not show any polymorphism in the two populations. In the Tibetan population, -2123C/G, -1969A/G, -1817T/C and Ser290Asn were in tight linkage disequilibrium with each other. CONCLUSIONS: The frequency distributions of -1969A/G and Ser290Asn polymorphisms in the Tibetan population were different from those in the Han population.

Short-tandem repeat analysis in seven Chinese regional populations.

In the present study, we investigated the application of 13 short tandem repeat (STR) loci (D13S317, D7S820, TH01, D16S539, CSFIPO, VWA, D8S1179, TPOX, FGA, D3S1358, D21S11, D18S51 and D5S818) routinely used in forensic analysis, for delineating population relationships among seven human populations representing the two major geographic groups, namely the southern and northern Chinese. The resulting single topology revealed pronounced geographic and population partitioning, consistent with the differences in geographic location, languages and eating habits. These findings suggest that forensic STR loci might be particularly powerful tools in providing the necessary fine resolution for reconstructing recent human evolutionary history.

[Analysis of the genetic polymorphism of 17 Y-chromosomal short tandem repeat loci in the Han population in Chengdu].

OBJECTIVE: To obtain the population genetic data of 17 Y-chromosomal short tandem repeat (Y-STR) in the Han population in Chengdu of Sichuan Province. METHODS: The 17 Y-STR loci were amplified from the blood samples of 111 unrelated Chengdu Han individuals using the AmpFlSTR Yfiler system. The PCR products were genotyped with an ABI 3130 genetic analyzer. RESULTS: In the loci of in DYS456, DYS389I, DYS390, DYS389II, DYS458, DYS19, DYS385a/b, DYS393, DYS391, DYS439, DYS635, DYS392, Y-GATA-H4, DYS437, DYS438, and DYS448, 3 to 8 alleles were detected in the Han population in Chengdu, and 36 alleles were detected in the locus DYS385a/b, with the minimal gene diversity (GD) value of 0.3970 (DYS391) and maximal value of 0.9561 (DYS385a/b). The DNA samples of 16 women and 7 different species of animals were amplified, but no specific products were found for the 17 Y-STR loci. No mutations of the 17 Y-STR alleles were observed in 20 father-son pairs as confirmed by autosomal STR analysis. CONCLUSION: The 17 Y-STR loci are highly polymorphic and are suitable for personal identification, paternity testing, population genetics and anthropology studies.

Short-tandem repeat analysis in seven Chinese regional populations

In the present study, we investigated the application of 13 short tandem repeat (STR) loci (D13S317, D7S820, TH01, D16S539, CSFIPO, VWA, D8S1179, TPOX, FGA, D3S1358, D21S11, D18S51 and D5S818) routinely used in forensic analysis, for delineating population relationships among seven human populations representing the two major geographic groups, namely the southern and northern Chinese. The resulting single topology revealed pronounced geographic and population partitioning, consistent with the differences in geographic location, languages and eating habits. These findings suggest that forensic STR loci might be particularly powerful tools in providing the necessary fine resolution for reconstructing recent human evolutionary history.