1.Gene screening of neonatal non-syndromic hereditary hearing loss in Guangxi
Ting QUE ; Wang LI ; Guoxing GENG ; Shihan FENG ; Jinwu YU ; Chao LUO ; Caijuan LIN
Chongqing Medicine 2017;46(7):926-928
Objective To use the matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) technique for detecting the mutation gene of neonatal non-syndromic hereditary hearing impairment gene in Guangxi and to investigate its effectiveness and feasibility in clinical application.Methods A total of 7 100 newborns were performed the hearing preliminary screening and secondary screening by adopting AABR.The genomic DNA was extracted by the heel blood spot.Twenty mutation characteristics of 4 deaf predisposing genes were detected by MALDI-TOF-MS.Results The pass rate of hearing screening in 7 100 newborns was 97.11% (6 895/7 100),the positive rate of neonatal gene mutation was 3.54% (251/7 100),in which the GJB2 gene mutation was in 131 cases,the carrying rate was 1.84%,235delC heterozygous mutation was in 108 cases.SLC26A4 gene mutation was in 93 cases,which dominated by 1229C>T heterozygous mutation and IVS7-2A>G heterozygous mutation,mtDNA12SRNA gene mutation was in 16 cases and GJB3 gene mutation was in 11 cases.Conclusion Adopting the MALDI-TOF-MS screening technique can increase the detection rate of hot point mutation in common deaf related genes and discover neonatal genetic NSHI from molecular level and provides the corresponding geneticconsulting guidance for early finding and predicting deaf occurrence,and formulating the interventional measures.
2.Genetic analysis of neonatal glucose-6-phosphate dehydrogenase deficiency in Guangxi Zhuang Autonomous Region
Shihan FENG ; Limei HUANG ; Tingting JIANG ; Luping OUYANG ; Qi YANG ; Guoxing GENG
Chinese Journal of Endemiology 2021;40(11):927-931
Objective:To study the incidence of glucose-6-phosphate dehydrogenase (G6PD) deficiency and the gene carrying status of newborns in Guangxi Zhuang Autonomous Region (Guangxi for short), so as to provide theoretical basis for clinical genetic counseling and accurate diagnosis.Methods:A total of 63 606 newborns who underwent G6PD screening in Guangxi Neonatal Disease Screening Center from January 2017 to December 2018 were selected as study subjects; heel blood was collected to prepare dry blood spots. Fluorescence quantitative analysis was used in the preliminary screening, and the newborns with positive preliminary screening were recalled by telephone; further diagnosis was carried out via the G6PD/6-phosphogluconate dehydrogenase (6PGD) ratio method and genetic testing, the diagnosis rate of the two methods of newborns with positive preliminary screening were compared and analyzed, and genetic mutation testing was conducted.Results:Among 63 606 newborns who underwent G6PD preliminary screening, 4 267 newborns with G6PD positive were detected, and the positive rate of preliminary screening was 6.7%. Among them, the positive rates of preliminary screening of males and females were 10.3% (3 508/33 988) and 2.6% (759/29 618), respectively. The positive rate of preliminary screening of males was significantly higher than that of females ( P < 0.01). A comparative analysis of 777 newborns (519 males and 258 females) that underwent G6PD/6PGD ratio method and genetic testing at the same time as the recall showed that the diagnosis rate of the two methods for male newborns was the same, both of which were 95.6% (496/519). Among female newborns, 168 and 236 confirmed cases were detected by G6PD/6PGD ratio method and genetic testing, respectively, and the diagnosis rates were 65.1% (168/258) and 91.5% (236/258), respectively. The results of genetic mutation testing showed that the five common genotypes in Guangxi were c.1388 G>A, c.1376 G>T, c.95 A>G, c.871 G>A, and c.1024 C>T, respectively. Conclusions:The positive rate of G6PD preliminary screening of newborns in Guangxi is relatively high. It is recommended that G6PD/6PGD ratio method and genetic testing should be performed at the same time for diagnosis of female newborns with positive preliminary screening to avoid missed diagnosis and misdiagnosis.
3.Molecular mechanisms of quinolone resistance in non-typhoidal Salmonella
Jiajun LUO ; Shihan ZENG ; Yulan HUANG ; Yulian FENG ; Fangyin ZENG ; Xiaoyan LI
Chinese Journal of Preventive Medicine 2024;58(2):248-253
By conducting retrospective analysis, this study aim to investigate the resistance mechanism of quinolones in non-typhoidal Salmonella (NTS). A total of 105 strains of NTS isolated from clinical specimens from the Fifth Affiliated Hospital of Southern Medical University from May 2020 to February 2021 were used as research objects. VITEK2 Compact automatic identification drug sensitivity analysis system and serological test were used to identify the strains. The sensitivity of the strains to ciprofloxacin, levofloxacin and nalidixic acid was detected by AGAR dilution method. The whole genome of 105 strains of NTS was sequenced. Abricate and other softwares were used to analyze drug-resistant genes, including plasmid-mediated quinolone resistance gene (PMQR) and Quinolone resistance determination region (QRDR). Serotypes and ST types were analyzed using SISTR and MLST, and phylogenetic trees were constructed. The results showed that the NTS isolated in this region were mainly ST34 Salmonella typhimurium (53.3%). The drug sensitivity results showed that the drug resistance rates of NTS to ciprofloxacin, levofloxacin and nalidixic acid were 30.4%, 1.9% and 22.0%, respectively, and the intermediate rates of ciprofloxacin and levofloxacin were 27.6% and 54.2%.A total of 46 (74.2%) of the 62 quinolone non-susceptible strains carried the PMQR gene, mainly qnrS1 (80.4%), followed by aac(6′)-Ib-cr(15.2%); there were 14 NTS and 8 NTS had gyrA and parC gene mutations, respectively. The gyrA was mutations at the amino acid position 87, Asp87Tyr, Asp87Asn, Asp87Gly, and Thr57Ser mutations were detected in parC. In conclusion, this study found that NTS had relatively high resistance to quinolones, carrying qnrS1 gene mainly resulted in decreased sensitivity of NTS to ciprofloxacin and levofloxacin, and gyrA:87 mutation mainly resulted in NTS resistance to Nalidixic acid; Salmonella typhimurium in clinical isolates showed clonal transmission and required further epidemiological surveillance.
4.Molecular mechanisms of quinolone resistance in non-typhoidal Salmonella
Jiajun LUO ; Shihan ZENG ; Yulan HUANG ; Yulian FENG ; Fangyin ZENG ; Xiaoyan LI
Chinese Journal of Preventive Medicine 2024;58(2):248-253
By conducting retrospective analysis, this study aim to investigate the resistance mechanism of quinolones in non-typhoidal Salmonella (NTS). A total of 105 strains of NTS isolated from clinical specimens from the Fifth Affiliated Hospital of Southern Medical University from May 2020 to February 2021 were used as research objects. VITEK2 Compact automatic identification drug sensitivity analysis system and serological test were used to identify the strains. The sensitivity of the strains to ciprofloxacin, levofloxacin and nalidixic acid was detected by AGAR dilution method. The whole genome of 105 strains of NTS was sequenced. Abricate and other softwares were used to analyze drug-resistant genes, including plasmid-mediated quinolone resistance gene (PMQR) and Quinolone resistance determination region (QRDR). Serotypes and ST types were analyzed using SISTR and MLST, and phylogenetic trees were constructed. The results showed that the NTS isolated in this region were mainly ST34 Salmonella typhimurium (53.3%). The drug sensitivity results showed that the drug resistance rates of NTS to ciprofloxacin, levofloxacin and nalidixic acid were 30.4%, 1.9% and 22.0%, respectively, and the intermediate rates of ciprofloxacin and levofloxacin were 27.6% and 54.2%.A total of 46 (74.2%) of the 62 quinolone non-susceptible strains carried the PMQR gene, mainly qnrS1 (80.4%), followed by aac(6′)-Ib-cr(15.2%); there were 14 NTS and 8 NTS had gyrA and parC gene mutations, respectively. The gyrA was mutations at the amino acid position 87, Asp87Tyr, Asp87Asn, Asp87Gly, and Thr57Ser mutations were detected in parC. In conclusion, this study found that NTS had relatively high resistance to quinolones, carrying qnrS1 gene mainly resulted in decreased sensitivity of NTS to ciprofloxacin and levofloxacin, and gyrA:87 mutation mainly resulted in NTS resistance to Nalidixic acid; Salmonella typhimurium in clinical isolates showed clonal transmission and required further epidemiological surveillance.
5.Genetic analysis of a child with DIGFAN syndrome due to variant of MORC2 gene
Bobo XIE ; Xin FAN ; Xianda WEI ; Baoheng GUI ; Xiaojiao WEI ; Yunting MA ; Shihan FENG ; Yujun CHEN
Chinese Journal of Medical Genetics 2024;41(2):234-238
Objective:To explore the clinical features and genetic etiology for a child with developmental delay, impaired growth, facial dysmorphism, and axonal neuropathy (DIGFAN).Methods:A child who was admitted to the Second Affiliated Hospital of Guangxi Medical University on March 22, 2021 was selected the study subject. Clinical data of the child was collected. Following extraction of genomic DNA, the child and his parents were subjected to whole exome sequencing (WES), and candidate variant was verified by Sanger sequencing and bioinformatic analysis.Results:The child, a 10-year-and-9-month-old boy, had manifested with short stature, intellectual disability, delayed speech, motor and language development, and facial dysmorphism. WES and Sanger sequencing revealed that he has harbored a novel de novo c. 800T>C (p.Leu267Pro) variant of the MORC2 gene. The Leucine at position 267, which is highly conserved among various species, is located in the S5 domain of ribosome protein in the ATPase binding region of MORC2. And the Leu267Pro may affect the function of MORC2 by altering the spatial conformation and activity of ATPase. Based on the guidelines from the American College of Medical Genetics and Genomics, the c. 800T>C variant was classified as likely pathogenic (PS2+ PM2_Supporting+ PP2+ PP3). Conclusion:The MORC2: c. 800T>C (p.Leu267Pro) variant probably underlay the pathogenesis of DIGFAN syndrome in this child.
6.Effect of Xiangsha Liu Junzitang Combined with Phlegm-removing and Detoxifying Traditional Chinese Medicine on Immune Escape in Lewis Lung Cancer Mice
Qian YANG ; Shumei WANG ; Shihan FENG ; Xue ZHAN ; Lintao XIA ; Mingxing WU
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(7):78-86
ObjectiveTo study the effect and mechanism of Xiangsha Liu Junzitang combined with phlegm-removing and detoxifying traditional Chinese medicine on immune escape in Lewis lung cancer mice. MethodA total of 60 specific-pathogen-free (SPF)-grade C57BL/6J male mice were injected subcutaneously with 0.2 mL of Lewis cell suspension (containing 2×106 cells·mL-1) in the right mid-axillary line. After 7 days, the mice that had been successfully modeled were randomly divided into six groups: the model group, the cisplatin group, the Xiangsha Liu Junzitang low-, medium-, and high-dose groups, and the combined group, with 10 mice in each group. The Xiangsha Liu Junzitang low-, medium- and high-dose groups were gavaged with 17.88, 35.75, 71.50 g·kg-1 Xiangsha Liu Junzitang solution once a day, respectively, and the dosage of cisplatin intraperitoneally injected into the mice was converted to 5 mg·kg-1 twice a week, and the tumour volumes of each group were measured every two days. The intervention lasted for 14 consecutive days. At the end of treatment, the tumour mass of mice in each group was weighed and the tumour inhibition rate was calculated. The morphological characteristics of tumours in each group were observed by hematoxylin-eosin (HE) staining. Fluorescent quantitative real-time polymerase chain reaction (Real-time PCR) assay was used to detect messenger ribonucleic acid (mRNA) contents of the natural killer group 2 member D (NKG2D) receptor, ribonucleic acid export-1 (RAE-1), and γ interferon (IFN-γ) in the tumour tissues of each group. NKG2D, RAE-1, and IFN-γ mRNA in tumour tissues of each group. Immunohistochemistry (IHC) and Western blot were applied to detect the expressions of RAE-1, NKG2D, and IFN-γ in tumour tissues of each group, and Western blot was used to detect the expressions of interleukin-6 (IL-6), Janus kinase 2 (JAK2), p-JAK2, signal transducer and activator of transcription 3 (STAT3), and p-STAT3 in tumour tissues of each group, as well as the protein levels of NKG2D, and RAE-1 in spleen tissues of each group. ResultCompared with that in the model group, the tumour mass decreased in all dose groups of Xiangsha Liu Junzitang, with no statistically significant difference. The tumour volume was reduced (P<0.05, P <0.01). The pathological morphology was improved. The mRNA contents of NKG2D, RAE-1 and IFN-γ were increased in the medium-dose group (P<0.05, P<0.01), and the protein expressions of NKG2D, RAE-1, and IFN-γ in tumour tissues were elevated (P<0.05, P<0.01), and p-JAK2 and p-STAT3 protein expressions were decreased (P<0.05, P<0.01). In spleen tissues, the protein expressions of NKG2D and RAE-1 in all dose groups of Xiangsha Liu Junzitang were significantly elevated (P<0.01). Compared with those in the cisplatin group, NKG2D, RAE-1 and IFN-γ mRNA contents were elevated in the middle-dose group of Xiangsha Liu Junzitang, and the difference was not statistically significant. IHC showed that the protein expressions of NKG2D and IFN-γ in the combined group were significantly elevated (P<0.01), and Western blot results showed that the protein expressions of RAE-1, NKG2D and IFN-γ were elevated (P<0.05, P<0.01). p-JAK2 and p-STAT3 protein expressions were decreased in the combined group (P<0.05, P<0.01). NKG2D and RAE-1 protein expressions were significantly increased in spleen tissues of the medium-dose groups and the combined group (P<0.01). ConclusionXiangsha Liu Junzitang combined with phlegm-removing and detoxifying traditional Chinese medicine can inhibit the growth of tumours in Lewis lung cancer mice by up-regulating the expressions of RAE-1/NKG2D, promoting the activation of NK cells, and inhibiting immune escape, the mechanism of which may be related to down-regulation of the JAK2/STAT3 pathway.