Esophageal squamous cell carcinomas (ESCC) is the fourth most lethal cancer in China. Previous studies reveal several highly conserved mutational processes in ESCC. However, it remains unclear what are the true regulators of the mutational processes. We analyzed the somatic mutational signatures in 302 paired whole-exome sequencing data of ESCC in a Chinese population for potential regulators of the mutational processes. We identified three conserved subtypes based on the mutational signatures with significantly different clinical outcomes. Our results show that patients of different subpopulations of Chinese differ significantly in the activity of the “NpCpG” signature (FDR = 0.00188). In addition, we report ZNF750 and CDC27, of which the somatic statuses and the genetic burdens consistently influence the activities of specific mutational signatures in ESCC: the somatic ZNF750 status is associated with the AID/APOBEC-related mutational process (FDR = 0.0637); the somatic CDC27 copy-number is associated with the “NpCpG” (FDR = 0.00615) and the AID/APOBEC-related mutational processes (FDR = 8.69 × 10− 4). The burdens of germline variants in the two genes also significantly influence the activities of the same somatic mutational signatures (FDR < 0.1). We report multiple factors that influence the mutational processes in ESCC including: the subpopulations of Chinese; the germline and somatic statuses of ZNF750 and CDC27 and exposure to alcohol and tobacco. Our findings based on the evidences from both germline and somatic levels reveal potential genetic regulators of the somatic mutational processes and provide insights into the biology of esophageal carcinogenesis.
Congenital hearing loss affects approximately 1–2 infants out of every 1000, with 50% of the cases resulting from genetic factors. Targeted gene panels have been widely used for genetic diagnosis of hearing loss. This study aims to reveal new diagnoses via reanalyzing historical data of a multigene panel, and exam the reasons for new diagnoses. A total of 210 samples were enlisted, including clinical reports and sequencing data of patients with congenital/prelingual hearing loss who were referred to clinical genetic testing from October 2014 to June 2017. All variants listed on the original clinical reports were reinterpreted according to the standards and guidelines recommended by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP). Expanded analysis of raw data were performed in undiagnosed cases. Re-analysis resulted in nine new diagnoses, improving the overall diagnostic rate from 39 to 43%. New diagnoses were attributed to newly published clinical evidence in the literature, adoption of new interpretation guidelines and expanded analysis range. This work demonstrates benefits of reanalysis of targeted gene panel data, indicating that periodical reanalysis should be performed in clinical practice.
1 December 2016 in Ecotoxicology and Environmental Safety
BACKGROUND: Several molecular methods, such as quantitative fluorescence PCR and multiplex ligation-dependent probe amplification, currently serve as important adjuncts to traditional karyotyping for the diagnosis of aneuploidy; however, the performance or throughput limitations of these methods hinder their use for routine prenatal diagnosis and population-based postnatal screening. We developed a novel approach, called “high-resolution melting analysis of segmental duplications,” to detect common aneuploidies. METHODS: In this method, similar sequences located on different chromosomes are amplified simultaneously with a single primer set; the PCR products are then analyzed by high-resolution melting. Aneuploidy-associated dosage abnormalities produce different ratios of similar amplicons, which produce melting curves that are detectably different from those of samples from unaffected individuals. We applied this method to DNA samples isolated from individuals with trisomy 21 (n = 48), trisomy 18 (n = 10), trisomy 13 (n = 3), 45,X (n = 8), and 47,XXY (n = 14), and from unaffected controls (n = 48). RESULTS: As judged by the karyotyping results, our method attained 100% diagnostic sensitivity and 99.6% diagnostic specificity. Moreover, our method was able to detect a change in chromosome dosage as low as 1.05-fold. CONCLUSIONS: This novel method clearly differentiates samples of patients with common aneuploidies from those of unaffected controls, while markedly simplifying the assays and reducing time and costs. The assay has sufficient throughput to meet the demands of large-scale testing, such as population-based postnatal screening, and is thus suitable for routine use.
Objectives To investigate the etiology of common respiratory pathogens in children < 2 years of age hospitalized with pneumonia in Xiamen from 2014 to 2017. Methods The medical records of 5581 children with pneumonia were retrospectively reviewed. Direct immunofluorescent test was used for respiratory virus testing. Bacteria were detected by conventional culture method. The results of pathogen detection at admission were analyzed as well as the clinical outcomes of children. Results The burden of hospitalized children with pneumonia was highest among infants < 6 months old (58.2%). Respiratory syncytial virus (RSV) was the most common respiratory virus (26.0%) followed by parainfluenza (4.8%) and adenovirus (3.2%). Haemophilus influenzae was the most common bacteria detected (16.6%) followed by Moraxella catarrhalis (13.4%), Staphylococcus aureus (13.0%), Streptococcus pneumoniae (12.3%), Escherichia coli (5.1%) and Klebsiella pneumoniae (4.8%). Notably, RSV and K. pneumoniae were detected more frequently in severe pneumonia (35.0% and 10.9%) versus mild pneumonia (25.6% and 4.6%), with higher rates of ICU admissions, longer hospital stays and higher hospital costs compared to those infected with other respiratory pathogens. Conclusions Among children < 2 years of age hospitalized with pneumonia in Xiamen, RSV was the most common respiratory virus, while H. influenzae and S. pneumoniae remained the predominant bacterial pathogens detected. Considering the low implementation rate of vaccines against pneumococcal and Hib pneumonia in China, there is an urgent need to increase both vaccination rates to reduce pneumococcal and Hib disease burden.