[Molecular Genetic Analysis of One Sudden Unexplained Death in the Young by Whole Exome Sequencing].

OBJECTIVE: To find the mutation of disease-causing genes of sudden unexplained death syndrome (SUDS) in the young by whole exome sequencing in one case. METHODS: One SUDS case was found no obvious fatal pathological changes after conventional autopsy and pathological examination. The whole exome sequencing was performed with the Ion Torrent PGM™ System with hg19 as reference sequence for sequencing data. The functions of mutations were analyzed by PhyloP, PolyPhen2 and SIFT. A three-step bioinformatics filtering procedure was carried out to identify possible significative single nucleotide variation (SNV), which was missense mutation with allele frequency < 1% of myocardial cell. RESULTS: Four rare suspicious pathogenic SNV were identified. Combined with the analysis of conventional autopsy and pathological examination, the mutation MYOM2 (8_2054058_G/A) was assessed as high-risk deleterious mutation by PolyPhen2 and SIFT, respectively. CONCLUSION: Based on the second generation sequencing technology, analysis of whole exome sequencing can be a new method for the death cause investigation of SUDS. The gene MYOM2 is a new candidate SUDS pathogenic gene for mechanism research.

[Analysis of linkage disequilibrium and linkage for 12 short tandem repeat loci on chromosome X].

OBJECTIVE: To analyze linkage disequilibrium of 12 short tandem repeat loci on chromosome X (X-STR) among an ethnic Han population from Guilin, Guangxi, and to study the genetic linkage and haplotype distributions of such loci in 2 linkage groups. METHODS: 12 X-STR loci including DXS8378, DXS10159, DXS10162, DXS10164, DXS981, DXS6789, DXS7424, DXS101, DXS7133, GATA165B12, GATA31E08 and DXS7423 were genotyped using an AGCU X12 STR PCR Amplification kit. A total of 119 pedigrees were analyzed for linkage and linkage disequilibrium. RESULTS: Two mutations were found at DXS7424, and 1 mutation was found at DXS10164. A total of 93 haplotypes of DXS10159-DXS10162-DXS10164 were constructed for 261 unrelated males and females, in addition with 167 haplotypes of DXS6789-DXS7424-DXS101-DXS7133. The values of recombination fraction between DXS10159 and DXS10162, DXS10162 and DXS10164, DXS6789 and DXS7424, and DXS7424 and DXS101 were 0.0269, 0.0236, 0.0505 and 0.0438, respectively. CONCLUSION: Linkage disequilibrium of X-STR does not only depend on physical and genetic distances. There was incomplete linkage relationship between loci on DXS10159-DXS1016-DXS10164 and DXS6789-DXS7424-DXS101 linkage groups.

Dihydromyricetin promotes apoptosis, suppresses proliferation and tumor necrosis factor-α-mediated nuclear factor kappa-B activation in nasopharyngeal carcinoma CNE-2 cell.

OBJECTIVE: To investigate the efficacy of dihydromyricetin (DMY) on nasopharyngeal carcinoma (NPC) cell proliferation, apoptosis and to reveal the underlying mechanism in vitro experiments. METHODS: The CNE-2 cell line was treated with different concentrations of DMY and the effects of DMY on cell viability and proliferation were evaluated using cell counting kit-8 (CCK-8) assay and plate colony formation assay. Cellular apoptosis was detected by flow cytometry following Annexin V fluorescein isothiocyanate/propidine iodide staining. Nuclei morphology was observed under a fluorescence microscope following Hoechst 333258 staining. The expression of phosphorylated inhibitor of nuclear factor kappa-B kinase subunit beta (p-IKKß), phosphorylated inhibitor of nuclear factor kappa-B kinase subunit alpha (p-IKKα), inhibitor of nuclear factor kappa-B alpha (IκB-α), nuclear factor kappa-B (NF-κB)/p65 was examined by Western blot analysis and the nuclear translocation of NF-κB/p65 was observed using a confocal laser scanning microscopy. RESULTS: DMY inhibited the proliferative capability and colony formation of NPC CNE-2 cells. Meanwhile, DMY induced apoptosis of CNE-2 cells in a dose and time-dependent manner via upregulating B-cell lymphoma-2 associated X, but downregulating B-cell lymphoma-2 and pro-caspase-3. Importantly, we found that DMY suppressed tumor necrosis factor alpha (TNF-α)-mediated NF-κB activation via inhibiting p-IKKß, p-IKKα and blocking NF-κB subunit p65. CONCLUSION: Our experiments demonstrated that DMY had significant antiproliferative and apoptosisinducing effects on CNE-2 cells. Additionally, DMY promoted inactivation of p-IKKß, p-IKKα, and blocked the nuclear translocation of NF-κB subunit p65. These results suggest that DMY may be an important therapeutic approach for NPC.

Analyzing genetic polymorphism and mutation of 44 Y-STRs in a Chinese Han population of Southern China.

Short tandem repeat on the non-recombining part of chromosome Y with paternally inheritable capability is a valuable tool in the studies of forensic genetics, population genetics and anthropology. The mutation rate of Y-STR is an important parameter in the applications. A total of 629 haplotypes at 44 Y-STR markers were found in 629 unrelated males of our population. Mutation rates at 44 Y-STR loci ranged from 0 (CI: 0-5.70 × 10-3) to 40.63 × 10-3 (25.90 × 10-3-57.2 × 10-3) in our population. A higher mutation rate was noted at DYS612, DYS449, DYS547, DYS518, DYS576, DYS627, DYF403S1b, DYF387S1, DYS385a/b, DYS527a/b, DYF404S1, DYF403S1a and DYF399S1 in this population. The Y-STR set showed a higher discrimination capacity in forensic applications, and the present study provided reference data for the application of forensic and population genetics.

Using whole exome sequencing and bioformatics in the molecular autopsy of a sudden unexplained death syndrome (SUDS) case.

Whole exome sequencing (WES) and bioinformatics analysis were used to investigate potential disease-causing gene mutations in a sudden unexplained death syndrome (SUDS) case after autopsy and pathology tests failed to suggest an obvious disease mechanism. Following whole exome sequencing, a 3-step bioinformatics filtering procedure was carried out to identify possible pathogenic genomic features. Single nucleotide variations (SNVs) were analyzed and ranked by likely mutation impact using various open online tools. After screening, we identified G643S as a putative causative heterozygous mutation in the KCNQ1 gene. This mutation has been reported in abnormalities consistent with SUDS, such as IKs in cardiac myocytes, a condition that predisposes for arrhythmias. Our work demonstrates the application of sequencing technology at the whole exome level for determining potential causes of an otherwise unexplained death.