Analysis of a mistake occurring during prenatal diagnosis of two couples respectively carrying CD41-42 (-TCTT) and CD43(G>T) mutations of the beta hemoglobin gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To provide prenatal diagnosis for two couples who respectively carried heterozygous CD41-42 (-TCTT) and CD43 (G>T) mutations of the beta hemoglobin gene.</p><p><b>METHODS</b>The mutations were simultaneously detected with reverse dot blot (two diagnostic kits), multi-color melting curve analysis and sequencing analysis.</p><p><b>RESULTS</b>The fetus of family 1 was shown to be heterozygous for CD43 (G>T) by the three methods, while the fetus of family 2 was shown to be double heterozygous for CD41-42 (-TCTT) and CD43 (G>T) by multi-color melting curve analysis and sequencing analysis. The two diagnostic kits yielded different results by reverse dot blot, one as double heterozygous for CD41-42 (-TCTT) and CD43 (G>T), and another as homozygous for CD41-42 (-TCTT).</p><p><b>CONCLUSION</b>For prenatal diagnosis of couples carrying mutations of beta hemoglobin gene such as CD41-42 (-TCTT) and CD43 (G>T), other methods such as Sanger sequencing should be used in order to avoid misdiagnosis.</p>

Analysis of 12 patients with novel mutations of Dystrophin gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the characteristics, location, and amino acid changes of novel mutations of the Dystrophin gene.</p><p><b>METHODS</b>Twelve patients in whom no deletion or duplication of the Dystrophin gene was detected were analyzed with next-generation sequencing. Fifty healthy adult males were recruited as the controls.</p><p><b>RESULTS</b>All patients were detected with mutations of the Dystrophin gene, which included c.33C>G, c.583C>T, c.1333C>T, c.2593C>T, c.5731A>T, c.7288G>T, c.2803+1G>T, c.10034G>A, c.4289A>G, c.1905_906delAG, c.5017delC, c.5768_5771delAAGA, and c.6261_6262insA. No similar mutations were found among the controls.</p><p><b>CONCLUSION</b>Our data has enriched the mutation spectrum of the Dystrophin gene and may provide an important basis for genetic diagnosis.</p>

The application of multicolor probe melting curve analysis for the prenatal diagnosis ofβthalassemia / 中华检验医学杂志

Objective To establish a method of multicolor melting curve analysis for the prenatal diagnosis ofβthalassemia.Methods Methodology establishment.A total of 95 cases, including 9 fetal villi samples(10-13 weeks)and 86 amniotic fluid samples(18-24 weeks)were collected by Center for Prenatal Diagnosis of Shenzhen Maternity and Child Healthcare Hospital between January 2014 and December 2014.A double-blind test was done to detect the mutations of beta globin gene by means of reverse dot ( RDB) blot and multicolor melting curve analysis ( MMCA).The consistency of the two methods is compared.Results The results of 93 cases detected by MMCA and RDB are completely consistent.The results of the 2 cases detected by MMCA after correction are the same as the results detected by RDB.Finally, the coincidence rate of the result was 100%.Conclusion MMCA can be applied to the prenatal diagnosis ofβthalassemia as an effective supplement to RDB.

Application of multiplex ligation-dependent probe amplification technique in prenatal diagnosis of α-thalassemia / 中华医学遗传学杂志

OBJECTIVE To assess the application value of multiplex ligation-dependent probe amplification (MLPA) for the detection of gene deletion and prenatal diagnosis of α-thalassemia. METHODS MLPA was applied for 2 cases with α-thalassemia phenotype by whole blood cell counting and hemoglobin component detection but were ruled out by regular molecular diagnosis. Potential gene deletions and point mutations of α-thalassemia gene were detected with regular Gap-polymerase chain reaction (Gap-PCR) and reverse dot blotting (RDB) in 89 cases where one or both partners were carriers of α-thalassemia mutations. Meanwhile, MLPA was used for detecting α-globin gene deletion among the 89 samples. RESULTS For the 2 cases with α-thalassemia phenotype, no α globin gene deletion was detected by MLPA, but were subsequently confirmed as iron-deficiency anemia. The results of MLPA and Gap-PCR detection for the 88 cases were consistent, except for 1 fetal sample (chorionic villi) which could not be diagnosed by Gap-PCR and was confirmed to be - SEA/αα by MLPA. CONCLUSION MLPA can be applied to prenatal diagnosis of α-thalassemia as an effective supplement to Gap-PCR to reduce both misdiagnosis and missed diagnosis and improve the accuracy of prenatal diagnosis.

Genetic analysis and prenatal diagnosis of two Chinese families with split hand foot malformation / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify genomic aberrations underlying pathogenesis of split hand foot malformation (SHFM) in two Chinese families, and to provide genetic counseling and prenatal diagnosis for them.</p><p><b>METHODS</b>Two sets of peripheral blood and amniotic fluid samples were collected from the patients. One was processed with routine culture and karyotype analysis. For another set, DNA was extracted and analyzed with array-based comparative genomic hybridization (array-CGH).</p><p><b>RESULTS</b>Karyotype analysis of peripheral blood samples for both probands was normal. Karyotype analysis of the amniotic fluid from family 1 has found no abnormality. However, analysis of amniotic fluid samples from the second family showed del(7)(q21q22.1). By array-CGH analysis, both blood and amniotic fluid samples from the first family showed a 662.3 kb dup(10q24.31q24.32). Array-CGH analysis of the blood sample from the second family was normal, whilst analysis of amniotic fluid sample revealed a 19.97 Mb del(7q11.23q21.3).</p><p><b>CONCLUSION</b>Array-CGH features high resolution, high accuracy and rapid diagnosis for unbalanced chromosomal aberration. The dup(10q24.31q24.32) and 19.97 Mb del(7q11.23q21.3) have been the cause of SHFM in the two families. Genetic counseling and prenatal diagnosis have been provided for both families in order to prevent this birth defect.</p>

Purification of AmpC beta-lactamase in Enterobacter cloacae / 临床检验杂志

Objective To purify AmpC beta-lactamase from Enterobacter cloacae and study its physical and chemical characteristics.Methods The bacteria were fragmentized by ultrasonication and AmpC beta-lactamase was purified by ion-exchange.The properties of the purified enzyme,such as molecular weight and isoelectric point were determined by electrophoresis.Results The purified AmpC beta-lactamase was obtained and its specificity to substrate was sufficient for classification of class C cephalosporinase.Conclusion AmpC can be successfully purified from Enterobacter cloacae and is effective for application.