Evaluation of reported pathogenic variants and their frequencies in a Japanese population based on a whole-genome reference panel of 2049 individuals

2017 ◽  
Vol 63 (2) ◽  
pp. 213-230 ◽  
Author(s):  
Yumi Yamaguchi-Kabata ◽  
◽  
Jun Yasuda ◽  
Osamu Tanabe ◽  
Yoichi Suzuki ◽  
...  
2019 ◽  
Vol 56 (10) ◽  
pp. 662-670 ◽  
Author(s):  
Yoshito Koyanagi ◽  
Masato Akiyama ◽  
Koji M Nishiguchi ◽  
Yukihide Momozawa ◽  
Yoichiro Kamatani ◽  
...  

BackgroundThe genetic profile of retinitis pigmentosa (RP) in East Asian populations has not been well characterised. Therefore, we conducted a large-scale sequencing study to investigate the genes and variants causing RP in a Japanese population.MethodsA total of 1209 Japanese patients diagnosed with typical RP were enrolled. We performed deep resequencing of 83 known causative genes of RP using next-generation sequencing. We defined pathogenic variants as those that were putatively deleterious or registered as pathogenic in the Human Gene Mutation Database or ClinVar database and had a minor allele frequency in any ethnic population of ≤0.5% for recessive genes or ≤0.01% for dominant genes as determined using population-based databases.ResultsWe successfully sequenced 1204 patients with RP and determined 200 pathogenic variants in 38 genes as the cause of RP in 356 patients (29.6%). Variants in six genes (EYS, USH2A, RP1L1, RHO, RP1 and RPGR) caused RP in 65.4% (233/356) of those patients. Among autosomal recessive genes, two known founder variants in EYS [p.(Ser1653fs) and p.(Tyr2935*)] and four East Asian-specific variants [p.(Gly2752Arg) in USH2A, p.(Arg658*) in RP1L1, p.(Gly2186Glu) in EYS and p.(Ile535Asn) in PDE6B] and p.(Cys934Trp) in USH2A were found in ≥10 patients. Among autosomal dominant genes, four pathogenic variants [p.(Pro347Leu) in RHO, p.(Arg872fs) in RP1, p.(Arg41Trp) in CRX and p.(Gly381fs) in PRPF31] were found in ≥4 patients, while these variants were unreported or extremely rare in both East Asian and non-East Asian population-based databases.ConclusionsEast Asian-specific variants in causative genes were the major causes of RP in the Japanese population.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shinichi Nagaoka ◽  
Yumi Yamaguchi-Kabata ◽  
Naomi Shiga ◽  
Masahito Tachibana ◽  
Jun Yasuda ◽  
...  

AbstractBone dysplasias are a group of rare hereditary diseases, with up to 436 disease types. Perinatal diagnosis is clinically important for adequate personalized management and counseling. There are no reports focused on pathogenic variants of bone dysplasias in the general population. In this study, we focused on autosomal recessive bone dysplasias. We identified pathogenic variants using whole-genome reference panel data from 3552 Japanese individuals. For the first time, we were able to estimate the carrier frequencies and the proportions of potential patients. For autosomal recessive bone dysplasias, we detected 198 pathogenic variants of 54 causative genes. We estimated the variant carrier frequencies and the proportions of potential patients with variants associated with four clinically important bone dysplasias: osteogenesis imperfecta (OI), hypophosphatasia (HPP), asphyxiating thoracic dysplasia (ATD), and Ellis–van Creveld syndrome (EvC). The proportions of potential patients with OI, ATD, and EvC based on pathogenic variants classified as “pathogenic” and “likely pathogenic” by InterVar were closer to the reported incidence rates in Japanese subjects. Furthermore, the proportions of potential patients with HPP variants classified as “pathogenic” and “likely pathogenic” in InterVar and “pathogenic” in ClinVar were closer to the reported incidence rates. For bone dysplasia, the findings of this study will provide a better understanding of the variant types and frequencies in the Japanese general population, and should be useful for clinical diagnosis, genetic counseling, and personalized medicine.


BMJ ◽  
2021 ◽  
pp. n214
Author(s):  
Weedon MN ◽  
Jackson L ◽  
Harrison JW ◽  
Ruth KS ◽  
Tyrrell J ◽  
...  

Abstract Objective To determine whether the sensitivity and specificity of SNP chips are adequate for detecting rare pathogenic variants in a clinically unselected population. Design Retrospective, population based diagnostic evaluation. Participants 49 908 people recruited to the UK Biobank with SNP chip and next generation sequencing data, and an additional 21 people who purchased consumer genetic tests and shared their data online via the Personal Genome Project. Main outcome measures Genotyping (that is, identification of the correct DNA base at a specific genomic location) using SNP chips versus sequencing, with results split by frequency of that genotype in the population. Rare pathogenic variants in the BRCA1 and BRCA2 genes were selected as an exemplar for detailed analysis of clinically actionable variants in the UK Biobank, and BRCA related cancers (breast, ovarian, prostate, and pancreatic) were assessed in participants through use of cancer registry data. Results Overall, genotyping using SNP chips performed well compared with sequencing; sensitivity, specificity, positive predictive value, and negative predictive value were all above 99% for 108 574 common variants directly genotyped on the SNP chips and sequenced in the UK Biobank. However, the likelihood of a true positive result decreased dramatically with decreasing variant frequency; for variants that are very rare in the population, with a frequency below 0.001% in UK Biobank, the positive predictive value was very low and only 16% of 4757 heterozygous genotypes from the SNP chips were confirmed with sequencing data. Results were similar for SNP chip data from the Personal Genome Project, and 20/21 individuals analysed had at least one false positive rare pathogenic variant that had been incorrectly genotyped. For pathogenic variants in the BRCA1 and BRCA2 genes, which are individually very rare, the overall performance metrics for the SNP chips versus sequencing in the UK Biobank were: sensitivity 34.6%, specificity 98.3%, positive predictive value 4.2%, and negative predictive value 99.9%. Rates of BRCA related cancers in UK Biobank participants with a positive SNP chip result were similar to those for age matched controls (odds ratio 1.31, 95% confidence interval 0.99 to 1.71) because the vast majority of variants were false positives, whereas sequence positive participants had a significantly increased risk (odds ratio 4.05, 2.72 to 6.03). Conclusions SNP chips are extremely unreliable for genotyping very rare pathogenic variants and should not be used to guide health decisions without validation.


2021 ◽  
pp. 1-16
Author(s):  
Veronica K. Cheng ◽  
Masahiro Hasegawa ◽  
Tetsuya Hattori ◽  
Naoya Ito ◽  
Erikka Linn ◽  
...  

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1378
Author(s):  
Tú Nguyen-Dumont ◽  
James G. Dowty ◽  
Jason A. Steen ◽  
Anne-Laure Renault ◽  
Fleur Hammet ◽  
...  

Case-control studies of breast cancer have consistently shown that pathogenic variants in CHEK2 are associated with about a 3-fold increased risk of breast cancer. Information about the recurrent protein-truncating variant CHEK2 c.1100delC dominates this estimate. There have been no formal estimates of age-specific cumulative risk of breast cancer for all CHEK2 pathogenic (including likely pathogenic) variants combined. We conducted a population-based case-control-family study of pathogenic CHEK2 variants (26 families, 1071 relatives) and estimated the age-specific cumulative risk of breast cancer using segregation analysis. The estimated hazard ratio for carriers of pathogenic CHEK2 variants (combined) was 4.9 (95% CI 2.5–9.5) relative to non-carriers. The HR for carriers of the CHEK2 c.1100delC variant was estimated to be 3.5 (95% CI 1.02–11.6) and the HR for carriers of all other CHEK2 variants combined was estimated to be 5.7 (95% CI 2.5–12.9). The age-specific cumulative risk of breast cancer was estimated to be 18% (95% CI 11–30%) and 33% (95% CI 21–48%) to age 60 and 80 years, respectively. These findings provide important information for the clinical management of breast cancer risk for women carrying pathogenic variants in CHEK2.


2021 ◽  
Author(s):  
Veronika Sanin ◽  
Raphael Schmieder ◽  
Sara Ates ◽  
Lea Dewi Schlieben ◽  
Jens Wiehler ◽  
...  

Abstract Background: Heterozygous Familial Hypercholesterolemia (FH) represents the most frequent monogenic disorder with an estimated prevalence of 1:250 in the general population. Diagnosis during childhood enables early initiation of preventive measures, reducing the risk of severe consecutive atherosclerotic manifestations. Nevertheless, population-based screening programs for FH are scarce.Methods: In the VRONI study children aged 5 to 14 years in Bavaria are invited to participate in a FH screening program during regular pediatric visits. The screening is based on LDL-C measurements from capillary blood. If exceeding 130 mg/dl (3.34 mmol/l), i.e. the expected 95th percentile in this age group, subsequent molecular genetic analysis for FH is performed. Children with FH pathogenic variants enter a registry and are treated by specialized pediatricians. Furthermore, qualified training centers offer FH-focused training courses to affected families. For first degree relatives, reverse cascade screening is recommended to identify and treat affected family members.Results: Implementation of VRONI required intensive prearrangements for addressing ethical, educational, data-safety, legal and organisational aspects, which will be outlined in this paper. Recruitment started in January of 2021, within two months more than 280 pediatricians screened over 1,150 children. Approximately 60,000 children are expected to be enrolled in the VRONI study until 2024. Conclusion: VRONI aims to test the feasibility of a population-based screening for FH in children in Bavaria, intending to set the stage for a nation-wide FH screening infrastructure. Further we aim to validate genetic variants of unclear significance, detect novel causative mutations, and contribute to polygenic risk indices. (German Clinical Trials Register: DRKS00022140; registered August 21st2020.)


2021 ◽  
Author(s):  
Tara Coffin ◽  
Deborah Bowen ◽  
Elizabeth Swisher ◽  
Karen Lu ◽  
Karen Lu ◽  
...  

BACKGROUND Genetic testing uptake is low, despite the well-established connection between pathogenic variants in certain cancer-linked susceptibility genes and ovarian cancer risk. Given that most major insurers cover genetic testing for those with a family history suggestive of hereditary cancer, the issue may lie in access to genetic testing. OBJECTIVE To present the development and formative evaluation of the multi-step online communication system required to support the democratization of genetic testing. METHODS While designing the multi-step online communication system, we considered various barriers and facilitators to genetic testing, guided by Levesque et al.’s dimensions of accessibility. In addition to conducting usability testing, we performed ongoing assessments focusing on function of the online system and participant response rates, with the goal of continuing to make modifications to the online communication system as it is in use. RESULTS The combined approach of usability testing and expert user experience (UX) consultation resulted in several modifications to the multi-step online communication system, including changes that related to imagery and content, web-accessibility, and general organization of the online system. All recommendations were made with the goal of improving the overall accessibility of the online communication system. CONCLUSIONS A multi-step online communication system appears to be an effective way to address many potential barriers to access, which may otherwise make genetic testing difficult for at-risk individuals to participate in. Importantly, some dimensions of access were easy to assess prior to study recruitment opening, but other aspects of the communication system required ongoing assessment during the implementation process of the Making Genetic Testing Accessible (MAGENTA) study.


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