Noninvasive Prenatal Diagnosis of SEA-Thalassemia by Combining 1000 Genomes Database and Relative Haplotype Dosage.

To explore a noninvasive method for diagnosis of SEA-thalassemia and to investigate whether the regional factors affect the accuracy of this method. The method involved using a public database and bioinformatics software to construct parental haplotypes for proband and predicting fetal genotypes using relative haplotype dosage. We screened and downloaded sequencing data of couples who were both SEA-thalassemia carriers from the China National Genebank public data platform, and matched the sequencing data format with that of the reference panel using Ubuntu system tools. We then used Beagle software to construct parental haplotypes, predicted fetal haplotypes by relative haplotype dosage. Finally, we used Hidden Markov Model and Viterbi algorithm to determine fetal pathogenic haplotypes. All noninvasive fetal genotype diagnosis results were compared with gold standard gap-PCR electrophoresis results. Our method was successful in diagnosing 13 families with SEA-thalassemia carriers. The best diagnostic results were obtained when Southern Chinese Han was used as the reference panel, and 10 families showed full agreement between our noninvasive diagnostic results and the gap-PCR electrophoresis results. The accuracy of our method was higher when using a Chinese Han as the reference panel for haplotype construction in the Southern Chinese Han region as opposed to Beijing Chinese region. The combined use of public databases and relative haplotype dosage for diagnosing SEA-thalassemia is a feasible approach. Our method produces the best noninvasive diagnostic results when the test samples and population reference panel are closely matched in both ethnicity and geography. When constructing parental haplotypes with our method, it is important to consider the effect of region in addition to population background alone.

Prevalence and molecular characterization of common thalassemia among people of reproductive age in the border area of Guangxi-Yunnan-Guizhou province in Southwestern China.

Objectives: Thalassemia, the most common global monogenetic disorder, is highly prevalent in southern China. Epidemiological and molecular characterization of thalassemia is important for designing appropriate prevention strategies in high-risk areas, especially the border area of Guangxi-Yunnan-Guizhou province in southwestern China.Methods: We recruited 38812 reproductive age couples and screened them for thalassemia. Routine blood tests as well as hemoglobin components and levels were evaluated. In addition, suspected thalassemia were identified by gap polymerase chain reaction (Gap-PCR) and PCR-based reverse dot blot (PCR-RDB).Results: The overall prevalence of thalassemia was 26.76%. Specifically, incidences of α-thalassemia, ß-thalassemia, and concurrent α- and ß-thalassemia were 17.52%, 6.92%, and 2.32%, respectively. The diagnosed α-thalassemia anomalies were associated with six gene mutations and 25 genotypes. The ß-thalassemia anomalies were associated with 12 gene mutations and 15 genotypes. Moreover, among the 1799 concurrent mutated α- and ß-thalassemia genes, 95 different genotypes were identified. Couples in which both partners were positive for α-thalassemia and ß-thalassemia isotypes were 8.80% and 2.08%, respectively. The proportion of couples at a risk of having children with thalassemia major or intermedia was high.Conclusions: This study elucidates on the prevalence and molecular characterization of thalassemia in the border area of Guangxi-Yunnan-Guizhou provinces. These findings provide valuable baseline data for genetic counseling and prenatal diagnosis, with the overarching goal of preventing and controlling severe thalassemia.

Association between genetic variants of microRNA-21 and microRNA-155 and systemic lupus erythematosus: A case-control study from a Chinese population.

BACKGROUND: Systemic lupus erythematosus (SLE) is a common autoimmune disease, and its pathogenesis remains unclear. The alteration of genetic materials is believed to play a role in SLE development. This study evaluated the association between the genetic variants of microRNA-21 (miR-21) and microRNA-155 (miR-155) and SLE. METHODS: The SNaPshot genotyping method was used to detect the genotypes of selected SNPs in patients and controls. The expression of miR-21 and miR-155 was analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The functional annotation and the biological effects of SNPs were assessed by HaploReg V4.1 and Regulome DB V2.0 software. The Hardy-Weinberg equilibrium test was used to gather statistics, and odds ratios (ORs) and 95% confidence intervals (CIs) were evaluated by logistic regression. RESULTS: The distribution difference of TA genotype in rs767649 was observed (TA vs. T/T: OR = 0.68, 95%CI, 0.48-0.95, p = 0.026). There was a significant difference in the T/A + A/A (T/A + A/A vs. T/T: OR = 0.68, 95%CI, 0.49-0.94, p = 0.020). A significant difference in T allele distribution was found in the depressed complement of SLE (T vs. A: OR = 0.67, 95%CI, 0.47-0.95, p = 0.026). There were significant differences in genetic variants of rs13137 between the positive and the negative SSB antibodies (Anti-SSB) (T vs. A: OR = 0.67, 95%CI, 0.47-0.95, p = 0.026; T/A + T/T vs. AA: OR = 2.23, 1.18-4.49, p = 0.013). The expression levels of miR-21 and miR-155 were significantly higher in patients than in controls (p < 0.001). CONCLUSIONS: This study provides novel insight that genetic variants of rs767649 and rs13137 are associated with susceptibility to SLE.

[Study of the genotypic and hematological feature of hemoglobin H disease in West Guangxi area].

OBJECTIVE: To analyze the incidence, genotype and hematological feature of hemoglobin H (HbH) disease in West Guangxi region. METHODS: A total of 1246 patients diagnosed with HbH disease from January 2013 to December 2018 in our hospital were enrolled. Red blood cell parameters, hemoglobin electrophoresis, Gap-polymerase china reaction (Gap-PCR) and polymerase chain reaction-reverse dot blot (PCR-RDB) techniques were used to detect the 6 common α-thalassemia mutations and 17 common ß-thalassemia mutations. The results were compared with those of other regions. RESULTS: The detection rate for HbH disease was 5.66%. Among the 1246 patients, 614 (49.28%) had deletion-type HbH disease, including -α 3.7/--SEA (35.32%),-α 4.2/--SEA(13.72%) and -a 3.7/--THAI(0.24%), 632(50.72%) had non-deleted HbH disease, mainly α CS α /--SEA (44.86%), followed by α WS α/--SEA (4.33%), α QS α /--SEA (1.45%) and α CS α/--THAI(0.08%). Co-committent HbH disease and ß-thalassemia were detected in 54 cases (4.33%). Most patients with HbH disease showed mild to moderate anemia. Very few had severe anemia. Among these, patients with HbH-CS had the most severe anemia, and HbH-WS were the mildest. Hb levels in patients with HbH disease alone were lower than those with co-committent HbH and ß-thalassemia. Compared with other regions, the incidence and genotype of HbH disease of West Guangxi are different. CONCLUSION: The prevalence of HbH disease is high in West Guangxi region, and the main genotypeis non-deletion. α CS α /--SEA is the most common, and most of them had moderate anemia. Compared with the deletion-type HbH disease, non-deleted HbH patients were more severe. When HbH disease co-committed with ß-thalassemia, the severity of anemia is reduced. The difference between West Guangxi and other regions may account for the variance of clinical manifestations and incidence of HbH disease in this region.