Low frequency of SLC26A4 c.919-2A > G variant among patients with nonsyndromic hearing loss in Yunnan of Southwest China.

BACKGROUND: Gene variants are responsible for more than half of hearing loss, particularly in nonsyndromic hearing loss (NSHL). The most common pathogenic variant in SLC26A4 gene found in East Asian populations is c.919-2A > G followed by c.2168A > G (p.H723R). This study was to evaluate their variant frequencies in patients with NSHL from special education schools in nine different areas of Southwest China's Yunnan. METHODS: We performed molecular characterization by PCR-products directly Sanger sequencing of the SLC26A4 c.919-2AG and c.2168 A > G variants in 1167 patients with NSHL including 533 Han Chinese and 634 ethnic minorities. RESULTS: The SLC26A4 c.919-2A > G variant was discovered in 8 patients with a homozygous state (0.69%) and twenty-five heterozygous (2.14%) in 1167 patients with NSHL. The total carrier rate of the c.919-2A > G variant was found in Han Chinese patients with 4.50% and ethnic minority patients with 1.42%. A significant difference existed between the two groups (P < 0.05). The c.919-2A > G allele variant frequency was ranged from 3.93% in Kunming to zero in Lincang and Nvjiang areas of Yunnan. We further detected the SLC26A4 c.2168 A > G variant in this cohort with one homozygotes (0.09%) and seven heterozygotes (0.60%), which was detected in Baoshan, Honghe, Licang and Pu`er areas. Between Han Chinese group (0.94%) and ethnic minority group (0.47%), there was no statistical significance (P > 0.05). Three Han Chinese patients (0.26%) carried compound heterozygosity for c.919-2A > G and c.2168 A > G. CONCLUSION: These data suggest that the variants in both SLC26A4 c.919-2A > G and c.2168 A > G were relatively less frequencies in this cohort compared to the average levels in most regions of China, as well as significantly lower than that in Han-Chinese patients. These results broadened Chinese population genetic information resources and provided more detailed information for regional genetic counselling for Yunnan.

A novel variant of SPAST in a pedigree with pure hereditary spastic paraplegia in Yunnan Province.

Background: Hereditary spastic paraplegia (HSP) is a rare group of genetically heterogeneous, neurodegenerative disorders. The aim of this study was to identify pathological candidate genes and variants in a large pedigree cohort of 11 purely HSP patients in Yunnan Province. Methods: Whole-exome sequencing (WES) was applied to 2 HSP patients and 1 control patient to screen out the candidate gene variants. Then, filtration and verification of these pathological variants were performed by Sanger sequencing. Results: After the raw data were filtered, two genes with novel variations (SPAST: c.1510 C>T, p.Gln504X, RefSeq.NM_199436; DNAJC16: c.718 C>T, p.Q240X, Ref Seq NM_015291) were identified. The accession numbers of the genes in the ClinVar database were SCV001573094 and SCV001573804, respectively. One gene with a reported single nucleotide polymorphism (CPT1C: rs150853576) was filtered as a candidate variant. Using Sanger sequencing, the novel SPAST gene (protein: Spastin) variant leading to a predicted premature termination and an 18% deletion of the SPAST/spastic paraplegia type 4 (SPG4) protein was confirmed to exist only in affected individuals. The candidate CPT1C and DNAJC16 variants were verified in almost all HSP patients, with one exception. Conclusions: Considering that the clinical symptoms and time of onset of HSP are highly heterogeneous, the SPAST as a genotype-phenotype cosegregated variant might be the causative gene of this pedigree, and the other two variants might present cumulative risks to the occurrence and progression of HSP. These three candidate genes with or without novel variants may be potential contributors to disease onset, and therefore useful diagnostic and therapeutic biomarkers. Further research is required to confirm the functions of these genes.

[Relationship between Polymorphism in ALOX5, ALOX5AP and Susceptibility to Myeloid Leukemia].

OBJECTIVE: To investigate the correlation of single nucleotide polymorphisms (SNP) in arachidonate 5-lipoxygenase gene (ALOX5) rs2029253, rs2228064 and rs2228065 sites, 5-lipoxygenase activating protein gene (ALOX5AP) rs10507391, rs4769874 sites with the risk for genesis of adult myeloid leukemia. METHODS: By the approval from the hospital ethics committee and the informed consent of participants. 150 patients with myeloid leukemia (ML) as ML group and 134 healthy people as the control group were selected. The genomic DNA was extracted from the samples. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) combined with directly sequencing, PCR-amplified products were applied to test the polymorphism of 5 sites in ALOX5 and ALOX5AP gene. RESULTS: A allele frequencies of ALOX5 gene rs2029253 site in the ML group and the control group were 43.0% and 34.3%, respectively. And the G allele frequencies in the ML group and the control group were 57.0% and 65.7%, respectively. The genotype distributions of AA, AG and GG in ALOX5 gene rs2029253 site in the ML group were 32.2%, 21.5% and 46.3% respectively. That in the control group were 15.7%, 37.3% and 47.0% respectively. The genotype AA and A allele frequency of ALOX5 gene rs2029253 site were linked with the increased risk of myeloid leukemia (OR=2.26, 95% CI: 1.43-4.56, P＜0.05; OR=1.44, 95% CI: 1.02-2.03, P＜0.05). And the genotype AG and allele G reduced the susceptibility to myeloid leukemia (OR=0.46, 95% CI: 0.27-0.78, P＜0.01; OR=0.69, 95% CI: 0.50-0.98, P＜0.05), however, the polymorphisms of ALOX5 gene rs2228064 and rs2228065 site not correlated with the risk of myeloid leukemia (P＞0.05). The A allele frequency of ALOX5AP gene rs10507391 site in the ML group and the control group were 30.7% and 36.2% respectirely. The genotype distribution rates of AA, AT and TT in ALOX5AP gene rs10507391 site in the ML group was 1.3%, 58.7% and 40.0% respectively, that in the control group were 9.7%, 53.0% and 37.3% respectively. The genotype AA of ALOX5AP gene rs10507391 site correlated with the decreased risk of myeloid leukemia (OR=0.13, 95% CI: 0.03-0.57, P＜0.05), but the polymorphism of ALOX5AP gene rs4769874 site not correlated with the risk of myeloid leukemia (P＞0.05). CONCLUSION: The genotype AA, AG and allele A, G of ALOX5 rs2029253, as well as ALOX5AP rs10507391 may be correlate with the susceptibility to myeloid leukemia.

Robust high-connected rare-earth MOFs as efficient heterogeneous catalysts for CO2 conversion.

Two series of chemically and thermally stable rare-earth MOFs were constructed using trinuclear [M3(µ3-OH)(COO)6] SBUs and linear dicarboxylate linkers, which feature three-dimensional 12-connected frameworks with an hcp topology. These materials contain a large density of Lewis acidic sites, leading to high catalytic activity towards the cycloaddition of CO2 and epoxides under mild conditions.

Papillary thyroid carcinoma risk factors in the Yunnan plateau of southwestern China.

OBJECTIVE: This study investigated clinical and pathological characteristics and risk factors in papillary thyroid carcinoma (PTC) patients' native to Yunnan plateau in southwestern China. METHODS: Clinical data from 1,198 patients diagnosed with PTC (n=578) and control subjects (n=620) with benign thyroid disease (ie, thyroid nodule disease, benign thyroid diseases [BTD]) in Yunnan province were analyzed retrospectively. RESULTS: The mean patient age was lower for PTC than for BTD. Positive ratios of thyroid peroxidase antibody, thyroglobulin antibody (TGAb), and thyrotrophin receptor antibody (TRAb) were higher in PTC than in BTD patients. The ratio of PTC coexisting with Hashimoto's thyroiditis (HT) or with lymphocytic thyroiditis was higher than that of BTD. The number of patients whose age at menarche was ≤13 years, who had given birth to less than or equal to two children, or who were in premenopause were higher in the PTC than in the BTD group. Multivariate conditional logistic regression analyses revealed that age >45 years, nodal size >1 cm, and elevated TG levels were protective factors against PTC. Abnormally elevated TGAb and TRAb levels were independent risk factors for PTC in females. CONCLUSION: HT was not an independent risk factor for but was associated with PTC. TRAb is a risk factor for PTC in individuals living in the Yunnan plateau, but not for those in the plains region.

Evolution of Hepatitis B Virus in a Chronic HBV-Infected Patient over 2 Years.

Mutations in full-length HBV isolates obtained from a chronic HBV-infected patient were evaluated at three time points: 1 day, 6 months, and 31 months. While 5 nucleotides variation, and an 18 bp deletion of preS1 have been kept in during at least the first two years, C339T mutation occurring in the hydrophilic region of HBsAg and T770C that caused polymerase V560A substitution were the new point mutations found existing in sequenced clones of the 3rd time point. Internal deletion of coding region obviously appeared in the 3rd time point. The splicers included two new 5'-splice donors and three new 3'-splice acceptors besides the reported donors and acceptors and may have produced presumptive HBV-spliced proteins or truncated preS proteins. ALT, HBeAg and viral DNA load varied during the follow-up years. These data demonstrated the diversity of genomes in HBV-infected patient during evolution. Combined with clinical data, the HBV variants discovered in this patient may contribute to viral persistence of infection or liver pathogenesis.