Genetic Analysis and Prenatal Diagnosis of a Family with Hereditary Spherocytosis Caused by a Novel Compound Heterozygous Mutation of SPTB Gene / 中国实验血液学杂志

OBJECTIVE@#To investigate the clinical and genetic characteristics of a family with hereditary spherocytosis (HS), to clarify the cause of the disease, and to provide the basis for genetic counseling and prenatal diagnosis.@*METHODS@#The clinical data of proband and his parents were collected, and HS-related pathogenic genovariation of the proband was detected by high throughput sequencing. Suspected pathogenic mutation sites were verified by PCR-Sanger sequencing, and the fetus were conceived by a proband mother underwent prenatal diagnosis.@*RESULTS@#Clinical manifestations of the proband showed moderate anemia, mild splenomegaly, and jaundice (an indirect increase of bilirubin). The gene detection showed that the proband showed compound heterozygous mutations of SPTB gene c. 6095T > C (p.Leu2032Pro) and c. 6224A > G (p.Glu2075Gly), which was inherited from the asymptomatic mother and father, respectively. Both mutations were detected rarely in the common population. Prenatal diagnosis revealed that the fetus inherited a mutant gene of the mother.@*CONCLUSION@#The compound heterozygous mutations of SPTB genes c.6095T>C (p.Leu2032Pro) and c.6224A>G (p.Glu2075Gly) were the causes of the family disease, which provides a basis for family genetic counseling and prenatal diagnosis. This report is the first one found in the HGMD,1000G and EXAC database, which provides an addition to the mutation profile of the SPTB gene.

Relationship between genotypes and clinical phenotypes in patients from 7 hemophilia A families / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the mutation types of factor VIII (FVIII) gene in patients from 7 hemophilia A (HA) families and the relationship between FVIII gene mutations and clinical phenotypes.</p><p><b>METHODS</b>A total of 8 patients from 7 HA families were recruited. The activated partial thromboplastin time (APTT) and factor VIII coagulant activity (VIII:C) in these patients were measured. Polymerase chain reaction (PCR) was performed to analyze FVIII gene intron 1 and 22 inversions. For patients without the FVIII intron inversions, direct sequencing was performed to determine their mutation types and other related members of their families were also tested by PCR and sequencing to analyze the corresponding mutation sites.</p><p><b>RESULTS</b>The ranges of APTT and VIII:C of the 8 patients were 91.6-131 seconds and 0.8%-2%, respectively. FVIII gene intron 22 inversion was not detected, while intron 1 inversion was detected in one patient. There were 5 types of mutations in FVIII gene detected in the remaining 7 patients, including 6 patients with mutations in exon 14 and 1 patient with mutation in exon 23; all of the 5 types of mutations were single nucleotide mutations. Among the detected mutations in FVIII gene, p.His1202LeufsX16 (c.3666delA) detected in one patient was found to be a previously unreported mutation in FVIII gene.</p><p><b>CONCLUSIONS</b>FVIII gene exon 14 is a hot-spot mutation region and p.His1202LeufsX16 is found to be a novel mutation in FVIII gene.</p>

Molecular analysis of two pedigrees with inherited coagulation factor VII deficiency / 中华儿科杂志

<p><b>OBJECTIVE</b>To analyze the gene mutation in two pedigrees of inherited coagulation factor VII (FVII) deficiency, and investigate the relationship between the genotype and phenotype.</p><p><b>METHOD</b>The coagulation function and coagulation factors activity of probands were detected for phenotype diagnosis, all exons and junctions of FVII gene from the family members' genomic DNA were amplified using polymerase chain reaction (PCR), and detected the gene mutation by direct sequencing. Mutations were confirmed by reverse sequencing.</p><p><b>RESULT</b>The prothrombin time (PT) of proband 1 was 265.2 s, FVII:C was 22% and the PT of proband 2 was > 120 s, FVII:C was 1%. Homozygous 17844G→A mutation in No. 8 exon of FVII gene was identified in the proband 1 resulting in Gly343Ser, and heterozygosity for the same mutations were confirmed in his parents and a sister. The proband 2 was compound heterozygous, one mutation was the same as the proband 1 but was a heterozygosity that can also found in his mother and brother; the other heterozygosity mutation was located on No. 8 exon 18055G→A that resulted in Gln413Arg which was inherited from his father.</p><p><b>CONCLUSION</b>No. 8 exon of FVII gene encodes catalytic domain. Mutation found in those domain could change the FVII catalytic domain spatial structure, affected FVII function and stability, and the sufferer of homozygote and compound heterozygous may have clinical bleeding tendency. Almost no clinical findings in simple heterozygotes, however, a few of heterozygotes could have a tendency of bleeding because of genetic polymorphism which would reduce the FVII:C.</p>

Application of STR genetic marker system in the detection of hemophilia A carriers in Guangxi, China / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To establish a fast and simple genetic diagnosis technique based on a reliable, short tandem repeat (STR) genetic marker system for the detection of hemophilia A carriers in Guangxi, China.</p><p><b>METHODS</b>Fluorescent PCR and capillary electrophoresis were used for allele genotyping at three intragenic/extragenic STR loci (F8Int13, DXS1073, and DXS9901) of FVIII gene in the members of 10 hemophilia A families in Guangxi, so as to evaluate the diagnostic efficiency of the STR genetic marker system for detection of hemophilia A carriers. Then the STR genetic marker system was used to detect hemophilia A carriers among examinees.</p><p><b>RESULTS</b>In the 10 hemophilia A families, 11 confirmed female carriers had the same allele fragment lengths at the three STR loci (F8Int13, DXS1073, and DXS9901) as the probands. Of the 8 females examined, 5 had allele fragments at the three STR loci (F8Int13, DXS1073, and DXS9901) which were identical to those of the probands, and thus they were diagnosed as hemophilia A carriers.</p><p><b>CONCLUSIONS</b>Genetic analysis at the three STR loci (F8Int13, DXS1073, and DXS9901) can be used to detect hemophilia A carriers rapidly and provide reliable basis for prenatal diagnosis of hemophilia A.</p>

Non-invasive prenatal genetic diagnosis of beta-thalassaemia using single fetal nucleated erythrocyte from maternal blood / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate non-invasive prenatal genetic diagnosis of beta-thalassaemia using a single fetal nucleated erythrocyte (NRBC) from maternal blood by comparing with the genotype obtained from chorionic villus or amniocytes, and to evaluate the diagnostic results in reliability and feasibility of this method.</p><p><b>METHODS</b>Maternal blood samples were obtained from 28 pregnant women at risk of beta thalassaemia during 9 - 34 weeks of gestation. NRBCs in maternal blood were enriched by single density gradient separation, stained with benzidine, and then collected by micromanipulation individually. After primer extension preamplification (PEP) of the entire genome from each single NRBC, short tandem repeat (STR) genotype was analyzed after further amplification of this gene. Single NRBC was tested individually to identify if it was fetal or maternal in origin by STR genotype of NRBC and its corresponding parents. beta-globin DNA fragments were amplified with nested-PCR using PEP product of a single fetal NRBC that was determined to be fetal in origin. Fetal beta-globin genotypes were analyzed by reverse dot-blot hybridization (RDB), the accuracy was evaluated by comparing with genotype which had been determined on DNA obtained from chorionic villus (CVS) or amniocytes.</p><p><b>RESULTS</b>A total of 298 NRBCs were found in all of 28 pregnant women at a range of 4 to 13 per 5 ml venous blood. After PEP, about 43.6% of NRBCs were determined to be fetal in origin by STR typing. Using PEP product of a single fetal NRBC as template, beta-globin DNA fragment was examined on agarose gel after nested-PCR, amplification efficiency was 90.8% (118/130). Fetal beta-globin genotypes were achieved successfully in all cases with RDB. Comparing with the genotypes which were obtained from CVS or amniocytes, the rate of diagnostic accuracy was 85.7% (24/28).</p><p><b>CONCLUSIONS</b>PEP technique and STR genotype analysis provide effective method for identification of single nucleated erythrocyte from maternal blood in origin. With the techniques PEP and RDB, fetal beta-globin genetic diagnosis was achieved using a single fetal NRBC from maternal blood. The method had a high accuracy and reliability in diagnosis. It may become an optional approach to non-invasive prenatal diagnosis of beta-thalassemia.</p>

Identification of fetal nucleated erythrocytes in maternal blood using short tandem repeat typing after primer extension preamplification / 中华血液学杂志

<p><b>OBJECTIVE</b>To develop a method for identifying fetal nucleated erythrocytes (NRBCs) in maternal blood.</p><p><b>METHODS</b>NRBCs in maternal blood were detected by benzidine staining and collected by micromanipulation. After primer extension preamplification (PEP) of the entire genome from a single NRBC, short tandem repeat (STR) genotype was analysed after further amplification of this gene. Single NRBC was differentiated as fetal or maternal origin by comparison of STR genotype of NRBC with its corresponding parents.</p><p><b>RESULTS</b>NRBCs were found in all of 28 pregnant women in a range of 4 to 13 per 5 ml venous blood. About 43. 6% of NRBCs were determined to be fetal origin by STR typing.</p><p><b>CONCLUSION</b>This method provides effective identification of fetal NRBCs and allows non-invasive prenatal genetic diagnosis using single fetal NRBC.</p>

Relationship between the expression of murine double minute 2 oncogene and non-Hodgkin lymphoma in childhood / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the relationship between the expression of murine double minute 2 (MDM2) oncogene and non-Hodgkin lymphoma (NHL) in childhood.</p><p><b>METHODS</b>Thirty-one cases of NHL were enrolled in this study as patient group and 8 cases of lymphadenitis as control group. (1) Immunohistochemistry ultrasensitive S-P assay was used to detect the expression of MDM2 protein in pathological tissues in all cases. Positive cells were dyed yellow or brown in nuclei. MDM2 positive cell was defined as >/= 10% of the tumor cells were positive, which was overexpression of MDM2 protein. (2) RT-PCR (reverse transcription-polymerase chain reaction) was performed to value the overexpression of MDM2 mRNA in the pathological tissues and mononuclear cells in peripheral blood. While the ratio of MDM2/beta-actin was >16% was defined as overexpression of MDM2 mRNA.</p><p><b>RESULTS</b>(1) Rates of overexpression of MDM2 protein and MDM2 mRNA were 64.5% and 61.3%, respectively, which were significantly different as compared to that of control group (P < 0.05 and P < 0.01, respectively). (2) The relationship analysis among subgroups in the experiment group showed that the overexpression of MDM2 protein did not correlate with classifications of working formulation, cellular origin, sex, clinical stage and involved extranodal sites (P > 0.05), but significantly correlated with classifications of B status and the increased serum LDH level (P < 0.05). It was shown that the overexpression of MDM2 mRNA did not correlate with classifications of working formulation, cellular origin, sex and clinical stage (P > 0.05), significantly correlated with B status (P < 0.05), and was remarkably significantly correlated with the involved extranodal sites and the increased serum LDH level (P < 0.01). (3) It was demonstrated that the overexpression of MDM2 mRNA in the pathological tissues was similar to the overexpression of MDM2 protein in the pathological tissues and MDM2 mRNA in peripheral blood (P > 0.05, kappa = 0.655 and 0.571), and the overexpression of MDM2 protein in the pathological tissues was similar to that of MDM2 mRNA in peripheral blood (P > 0.05, kappa = 0.609).</p><p><b>CONCLUSIONS</b>(1) The rate of MDM2 oncogene overexpression was quite high. (2) The overexpression of MDM2 protein in pathological tissues determined by using immunohistochemistry ultrasensitive S-P assay was similar to that of MDM2 mRNA in pathological tissues detected by using RT-PCR method. Both methods might be used to detect the overexpression of MDM2 oncogene in the cases of childhood NHL. (3) The overexpression of MDM2 oncogene related to the poor status and poor prognosis of patients with childhood NHL.</p>