[Molecular Diagnosis and Pedigree Analysis of Rare Mutations in Non-coding Region of HBA2 Gene].

OBJECTIVE: To perform molecular diagnosis and pedigree analysis for one case with α-thalassemia who does not conform to the genetic laws, and explore the effects of a newly discovered rare mutation (HBA2:c.*12G>A) on clinical phenotypes. METHODS: Blood samples of the proband and her family members were collected for blood routine analysis, and the hemoglobin components were analyzed by capillary electrophoresis. The common α- and ß-globin gene loci in Chinese population were detected by conventional techniques (Gap-PCR, RDB-PCR). The α-globin gene sequences (HBA1, HBA2) were analyzed by Sanger sequencing. RESULTS: By analyzing the test results of proband and her family members, the genotype of the proband was -α3.7/HBA2:c.*12G>A, her father was HBA2:c.*12G>A heterozygous mutation carrier. CONCLUSION: This study identifies a rare α-globin gene mutation (HBA2:c.*12G>A) that has not been reported before. It is found that heterozygous mutation carriers present with static α-thalassemia.

[Cases Analysis of Hemoglobin H Disease Caused by HBA2:c.2T>C and HBA2:c.2delT Mutations].

OBJECTIVE: To investigate two cases of rare pathogenic genes, initiation codon mutations in HBA2 gene, combined with Southeast Asian deletion and their family members to understand the relationship of HBA2:c.2T>C and HBA2:c.2delT mutations with clinical phenotype. METHODS: The peripheral blood of family members was obtained for blood cell analysis and capillary electrophoresis hemoglobin analysis. Gap-PCR and reverse dot blotting (RDB) were used to detect common types of mutations in ɑ-thalassaemia gene. Sanger sequencing was used to analyze HBA1 and HBA2 gene sequence. RESULTS: Two proband genotypes were identified as --SEA/αα with HBA2:c.2T>C and --SEA/αα with HBA2:c.2delT. HBA2:c.2T>C/WT and HBA2:c.2delT/WT was detected in family members. They all presented with microcytic hypochromic anemia. CONCLUSION: When HBA2:c.2T>C and HBA2:c.2delT are heterozygous that can lead to static α-thalassemia phenotype, and when combined with mild α-thalassemia, they can lead to the clinical manifestations of hemoglobin H disease. This study provides a basis for genetic counseling.

[Methodological Evaluation of Microarray in the Detection of α-Thalassemia].

OBJECTIVE: To proceed the clinical evaluation of DNA microarray for thalassemia gene detection. METHODS: Peripheral blood samples of 166 thalassemia gene test subjects were collected and tested for thalassemia genes by microarray chip method and Gap-PCR method combined with PCR-reverse dot blot hybridization method according to double-blind control test. The specificity, sensitivity, positive predictive value, negative predictive value, and total coincidence rate of the microarray chip method were evaluated. When the two methods were inconsistent, multiplex ligation dependent probe amplification (MLPA) was used to verify the deletional α-thalassemia. RESULTS: Compared with Gap-PCR method, specificity, sensitivity, positive predictive value, negative predictive value, Youden index, and total coincidence rate of microarray chip method was 100% (70/70), 96.88% (93/96), 100% (93/93), 95.89% (70/73), 0.969, and 97.59% (162/166), respectively, while compared with PCR-reverse dot blot hybridization method was 100% (125/125), 100% (41/41), 100% (41/41), 100% (125/125), 1, and 100% (166/166), respectively. CONCLUSION: The microarray chip method for α-thalassemia gene detection shows the advantages of high specificity, sensitivity, and throughput.

[Application of DNA Microarray in Genetic Mutation Detection in Patients with Thalassemia].

OBJECTIVE: To perform dried blood spots thalassemia gene detection in patients with positive blood phenotypes by microarray technology, and evaluate its value in clinical detection. METHODS: DNA samples were extracted from dried blood spots of 410 patients. Microarray technology was used to detect 3 deletion and 3 non-deletion types of α-thalassemia and 19 ß-thalassemia point mutations which were common gene mutions in China. RESULTS: There were 357 positive cases in all the 410 tested samples with the positive rate 87.07%, among which 299 cases (72.93%) carried deletion or point mutations of α-thalassemia, 29 cases (7.07%) carried point mutations of ß-thalassemia and 29 cases (7.07%) carried gene mutations of complex αß-thalassemia syndrome. The mutations of α-thalassemia were involved with --SEA heterozygous deletion (177 cases, 59.2%), αCS heterozygote (60 cases, 20.07%) and several other genotypes. The common mutations of ß- thalassemia were involved with ßCD41-42 heterozygote (10 cases, 34.48%) and ßCD17 heterozygote (9 cases, 31.03%). The mutations of complex αß-thalassemia syndrome were mainly involved with --SEA/αα+ßCD17/ßN (7 cases, 24.14%), αCSα/αα + ßCD41-42/ßN (3 cases, 10.34%) and -α4.2/αα + ßCD17/ßN (3 cases, 10.34%). CONCLUSION: The most common genetic mutations are --SEA for α-thalassemia and CD41-42 for ß-thalassemia in Liuzhou, Guangxi Zhuang Autonomous Region. A and ß-thalassemia can be detected at the same time by microarray chip technology in a high throughput manner.

Pedigree Analysis of Nonhomologous Sequence Recombination of HBA1 and HBA2 Genes.

The aim of this study was to investigate a family with nonhomologous sequence recombination of HBA1 and HBA2 genes and provide a favorable basis for genetic counseling and eugenics. Peripheral blood of family members was collected. Hematological parameters were determined by an automated cell counter and hemoglobin (Hb) analysis was performed using high performance liquid chromatography (HPLC). Villus samples were taken for prenatal diagnosis (PND). Gap-polymerase chain reaction (gap-PCR) and reverse dot-blot were used for thalassemia genotyping. DNA sequencing was used to analyze the gene sequence of HBA1 (α1-globin) and HBA2 (α2-globin). The nonhomologous sequence recombination allelic variant of HBA1 and HBA2 genes were identified, namely, a gene conversion on the HBA2 gene called α12 (HBA12). The α12 allele consists primarily of the HBA2 gene sequence except for a segment of the IVS-II in which HBA2-specific sequences have been replaced by HBA1-specific sequences. The following genotypes were observed: - -SEA/αα12 (Southeast Asian deletion), αα/αα12 and αQSα/αα12 (Hb Quong Sze or Hb QS; HBA2: c.377T>C), and all manifested as small cell hypochromic anemia. To find the α12 allele in the Chinese population and clarify the influence of the α12 allele and its common inheritance with abnormal Hb and α-thalassemia (α-thal) on α-globin gene expression can help guide clinical diagnosis and genetic counseling.

[Evaluation of detection of Epstein-Barr virus Rta/IgG in nasopharyngeal carcinoma].

OBJECTIVE: This study was aimed to investigate the clinical value of Epstein-Barr virus (EBV) Rta/IgG in the diagnosis of nasopharyngeal carcinoma (NPC). METHODS: Serum samples derived from 211 untreated patients with NPC, 413 subjects including 203 non-NPC ENT patients and 210 healthy volunteers as control were examined for the presence of antibodies directed against Rta/IgG by using enzyme-linked immnunosorbent assay (ELISA). Receiver operating characteristic (ROC) curve was applied to perform methodical evaluation of this tumor marker. RESULTS: The rA value median of Rta/IgG in NPC group was significantly higher than one in control group (P < 0.001). The area under ROC was 0.933. The sensitivity and specificity of this marker were 90.5% and 90.1%, respectively, when the best cutoff value was defined. CONCLUSION: Rta/IgG detected with ELISA method is a new target of EBV, and may be one of important marker for NPC diagnosis.

[Evaluation of combined determinations of Epstein-Barr virus antibodies for nasopharyngeal carcinoma assessed with receiver operating characteristic curve based on logistic regression].

OBJECTIVE: This study was aimed to investigate the diagnostic value of combined determination of Epstein-Barr virus (EBV) antibodies for nasopharyngeal carcinoma (NPC), including immunoglobulin (Ig) A against EBV capsid antigens (VCA), IgA against early antigens (EA), IgG against BRLF1 transcription activator (Rta) and IgA against EBV nuclear antigen-1 (EBNA1), assessed with receiver operating characteristic (ROC) curve based on logistic regression. METHODS: Serum samples derived from 211 untreated patients with NPC and 203 non-NPC ENT patients were examined for the presence of VCA/IgA and EA/IgA by immunoenzymatic assay, Rta/IgG and EBNA1/IgA by enzyme-linked immnunosorbent assay (ELISA). The different Logistic regression models were established for various combined determinations of antibodies, respectively. Using the predicted probability as the analyzed variable, ROC curve was applied to evaluate the diagnostic accuracy of different combined determinations. RESULTS: The sensitivity of VCA/IgA (98.1%) and the specificity of EA/IgA (98.5%) were the highest while detecting solely. The results which were analyzed by ROC curve based on Logistic regression showed that the sensitivity and specificity were improved. In two-marker combinations, VCA/IgA + Rta/IgG whose area under ROC curve (AUC) was 0.991 had the highest diagnostic accuracy, and its sensitivity, specificity and Youden index were 94.8%, 98.0% and 0.928 respectively. No significant difference of AUC were found comparing VCA/IgA + Rta/IgG with VCA/IgA + Rta/IgG + EBNA1/IgA and four-marker combination( P > 0.05), of which sensitivity, specificity and Youden index were 94.8%, 98.5%, 0.933 and 96.7%, 97.0%, 0.937, respectively. CONCLUSION: The approach of ROC curve based on Logistic regression can improve synthetic efficiency for combined determination of multiple markers. The combined determination of VCA/IgA and Rta/IgG with a complementary effect is optimal for NPC serodiagnosis.

Effects of berberine on expression of hepatocyte nuclear factor 4alpha and glucokinase activity in mouse primary hepatocytes / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the expression of hepatocyte nuclear factor 4alpha (HNF4alpha) and the activity of key enzyme glucokinase (GK) in glucose metabolism, and further to investigate the possible mechanism of berberine in treating type 2 diabetes.</p><p><b>METHOD</b>Mouse primary hepatocytes were isolated by an improved single two-step perfusion method. The murine hepatocytes were cultured and incubated with berberine (0, 1, 3, 10, 30, 100 micromol x L(-1)) and 1 mmol x L(-1) metformin for 24 h respectively. The mRNA expression of HNF4alpha were quantified by RT-PCR and the protein expression of HNF4alpha were quantified by Western-blot. And the activity of GK were detected with enzyme kinetics method.</p><p><b>RESULT</b>As compared with the negative control group, at a certain concentration range, the expression of HNF4alpha mRNA and protein and the activity of GK were promoted by berberine. Both of them reached the top at the concentration of 30 micromol x L(-1) (P<0.01). But the metformin made no difference with the negative control group on the expression of HNF4alpha and the activity of GK.</p><p><b>CONCLUSION</b>It is suggested that the effects of berberine on improving glucose metabolism can be mechanically associated with its up-regulating the HNF4a expression and inducing the activity of hepatic glucokinase.</p>