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553 result(s) for "Pathogenic variant"
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Clinical features and cancer risk in families with pathogenic CDH1 variants irrespective of clinical criteria
BackgroundThe clinical phenotype of CDH1 pathogenic variant carriers has mostly been studied in families that fulfil criteria of hereditary diffuse gastric cancer (HDGC). We aimed at determining cancer phenotype and cancer risk estimation among families with CDH1 pathogenic variants not selected by HDGC clinical criteria.MethodsPatients were all consecutively identified CDH1 pathogenic variant carriers from a clinical laboratory tested with multigene panel testing and from an academic cancer genetics programme. Clinical and demographic features, cancer phenotypes and genotype–phenotype correlations were determined among CDH1 families. Age-specific cumulative cancer risks (penetrance) were calculated based on 38 families with available pedigrees.ResultsWithin the 113 CDH1 pathogenic variant probands and 476 relatives, 113 had gastric cancer, 177 breast cancer and 196 other cancers. Mean age at diagnosis was 47 for gastric and 54 for breast cancer. Forty-six per cent fulfilled criteria of HDGC. While 36% of families had both gastric and breast cancers, 36% had breast but no gastric cancers and 16% had gastric but not breast cancers. Cumulative risk of cancer by age 80 was 37.2% for gastric and 42.9% for breast cancer.ConclusionIn unselected CDH1 pathogenic variant carrier families, gastric cancer risks were lower and age at diagnosis higher than previously reported in families pre-selected for HDGC criteria. A substantial proportion of families did not present with any gastric cancers and their cancers were limited to breast. Thus, clinical criteria for CDH1 testing should be widened, including breast cancer families only, and a consideration for delayed prophylactic gastrectomy/surveillance should be evaluated.
Rare single‐nucleotide variants of MLH1 and MSH2 genes in patients with Lynch syndrome
Background Approximately 5% of colorectal cancers (CRCs) are hereditary. Lynch syndrome (LS), also known as hereditary nonpolyposis colorectal cancer (HNPCC), is the most common form of recognized hereditary CRC. Although Iran, as a developing country, has a high incidence of CRC, the spectrum of variants has yet to be thoroughly investigated. Aims This study aimed to investigate pathogenic and non‐pathogenic variants in MLH1 and MSH2 genes in Iranian patients with suspected Lynch syndrome (sLS). Methods and results In the present study, 25 peripheral blood samples were collected from patients with sLS and high microsatellite instability (MSI‐H). After DNA extraction, all samples underwent polymerase chain reaction and Sanger sequencing to identify the variants in the exons of MLH1 and MSH2 genes. The identified variants were interpreted using prediction tools, and were finally reported under ACMG guidelines. In our study population, 13 variants were found in the MLH1 gene and 8 in the MSH2 gene. Interestingly, 7 of the 13 MLH1 variants and 3 of the 8 MSH2 variants were novel, whereas the remaining variants were previously reported or available in databases. In addition, some patients with sLS did not have variants in the exons of the MLH1 and MSH2 genes. The variants detected in the MLH1 and MSH2 genes had specific characteristics regarding the number, area of occurrence, and their relationship with demographic and clinicopathologic features. Conclusion Overall, our results suggest that analysis of MLH1 and MSH2 genes alone is insufficient in the Iranian population, and more comprehensive tests are recommended for detecting LS.
Population Prevalence of Deleterious SGCE Variants
Myoclonus-Dystonia (M-D) is a pleiotropic neuropsychiatric disorder of variable penetrance. Pathogenic variants in , a maternally imprinted gene, are the most frequent known genetic cause of M-D. The population prevalence of -linked M-D is unknown, the pathogenicity of variants identified in patients with M-D may be indeterminant, and variants predicted to be deleterious by analysis may appear in patients undergoing whole-exome or whole-genome sequencing for seemingly unrelated disorders. The Genome Aggregation Database (gnomAD) v2 provides variant data on 125,748 exomes and 15,708 genomes from unrelated individuals sequenced as part of various disease-specific and population genetic studies. variants included in the gnomAD v2 dataset were analyzed with Combined Annotation Dependent Depletion (CADD), and database for nonsynonymous single nucleotide polymorphisms' functional predictions (dbNSFP). We determined the frequency of annotated variants, ranked by scores of deleteriousness, within the gnomAD v2 dataset. Deleteriousness scores were compared to a subset of published disease associated pathogenic variants. Within gnomAD v2, there were 56, 408, and 1250 alleles harboring variants with CADD scores greater than 30, 25, and 20, respectively. We estimate that approximately 1/348 individuals in the United States population harbors an variant with a CADD score ≥ 25. M-D may be underdiagnosed due to pleiotropy, mild phenotypes, variable penetrance, and impaired access to genetic testing. Due to the high population prevalence of deleterious variants, caution should be used when asserting pathogenicity without co-segregation analyses and expert neurological examination of phenotypes within pedigrees. analyses of a large population database of genetic variants revealed that over 0.2% of individuals in the United States harbor a highly deleterious variant. This finding suggests that M-D and minor phenotypic variants such as mild isolated myoclonus may be underdiagnosed.
The prevalence of occult ovarian cancer in the series of 155 consequently operated high risk asymptomatic patients – Slovenian population based study
Background We assessed the prevalence, localization, type and outcome of occult cancer at risk-reducing salpingo-oophorectomy or salpingectomy (RRSO) in asymptomatic carriers of pathogenic or likely pathogenic BRCA1/2 variants and high-risk BRCA1/2 negative women. Patients and methods A retrospective analysis of all consecutive gynaecologic preventive surgeries from January 2009 to December 2015 was performed. Participants underwent genetic counselling and BRCA1/2 testing before the procedure. Data on clinical parameters, adjuvant treatment and follow-up were collected and analysed. Results One hundred and fifty-five RRSO were performed in 110 BRCA1, 35 BRCA2 carriers of pathogenic or likely pathogenic variants and 10 high-risk BRCA1/2 negative women, at the mean age of 48.3 years. Nine occult cancers (9/155, 5.8%) were identified; eight in BRCA1 positive women and one in high-risk BRCA1/2 negative woman. We identified four non-invasive serous intraepithelial tubal carcinomas (3 in BRCA1 carriers and 1 in a high-risk BRCA1/2 negative woman) and five invasive tubo-ovarian high grade serous cancers (all detected in BRCA1 carriers). Only one out of nine patients (11.1%) with occult cancer had a slightly elevated CA-125 value preoperatively. Conclusions A 5.8% prevalence of occult invasive and noninvasive tubo-ovarian serous cancer after RRSO was found in high risk asymptomatic and screen negative women. We conclude that RRSO should be performed in BRCA1/2 carriers and in high-risk BRCA1/2 negative women. Age of preventive gynaecologic surgery should be carefully planned, taking into account the completion of childbearing age and type of mutation. The results favour the tubal hypothesis of tubal origin of high grade serous ovarian and peritoneal cancer. Cytology result of peritoneal cavity washing was important for the decision making process in determining treatment. Cytology examination should be performed in all cases of RRSO. CA-125 assay did not prove to be an effective screening tool for early cancer detection in our patients.
Contribution of noncoding pathogenic variants to RPGRIP1-mediated inherited retinal degeneration
Purpose With the advent of gene therapies for inherited retinal degenerations (IRDs), genetic diagnostics will have an increasing role in clinical decision-making. Yet the genetic cause of disease cannot be identified using exon-based sequencing for a significant portion of patients. We hypothesized that noncoding pathogenic variants contribute significantly to the genetic causality of IRDs and evaluated patients with single coding pathogenic variants in RPGRIP1 to test this hypothesis. Methods IRD families underwent targeted panel sequencing. Unsolved cases were explored by exome and genome sequencing looking for additional pathogenic variants. Candidate pathogenic variants were then validated by Sanger sequencing, quantitative polymerase chain reaction, and in vitro splicing assays in two cell lines analyzed through amplicon sequencing. Results Among 1722 families, 3 had biallelic loss-of-function pathogenic variants in RPGRIP1 while 7 had a single disruptive coding pathogenic variants. Exome and genome sequencing revealed potential noncoding pathogenic variants in these 7 families. In 6, the noncoding pathogenic variants were shown to lead to loss of function in vitro. Conclusion Noncoding pathogenic variants were identified in 6 of 7 families with single coding pathogenic variants in RPGRIP1 . The results suggest that noncoding pathogenic variants contribute significantly to the genetic causality of IRDs and RPGRIP1 -mediated IRDs are more common than previously thought.
The prevalence of pathogenic variants in the BMPR2 gene in patients with the idiopathic pulmonary arterial hypertension in the Russian population: sequencing data and meta-analysis
Background Idiopathic pulmonary arterial hypertension (IPAH) is a rare and severe form of pulmonary hypertension, with a genetic basis most commonly associated with mutations in the BMPR2 gene. However, no genetic testing has been reported for IPAH patients in the Russian population, nor have systematic studies been conducted to assess the frequency of pathogenic variants in this group. Methods The study cohort included 105 IPAH patients, consisting of 23 males and 82 females, who were managed at the PH care center in Moscow, Russia, from 2014 to 2024. Genetic testing was performed using whole-genome sequencing. Variant identification and annotation were conducted using GATK, DeepVariant, VEP, sv-callers and AnnotSV. A meta-analysis, performed with MOOSE, included 24 studies involving 3124 IPAH patients and 470 P/LP variants. Pathogenicity reassessment was carried out using InterVar, which incorporates ACMG criteria. Results Analysis of 105 adult IPAH patients in Russia revealed 11 patients (10.48%) as carriers of pathogenic or likely pathogenetic (P/LP) BMPR2 variants. As the result of reassessment, the number of P/LP BMPR2 variants raised from 394 (59%) to 445 (67%) with 80 pathogenic variants became of uncertain significance, and 152 unclassified variants became P/LP. The meta-analysis of these reevaluated pathogenic variants showed that while the frequency of P/LP variants in our cohort (10.48%) is lower than the overall average of 17.75% from the meta-analysis, the difference is not statistically significant (p = 0.062). Additionally, we report three P/LP BMPR2 variants, not reported in literature, with one being structural, and four P/LP variants in TBX4, ATP13A3 and AQP1 genes from 27 IPAH genes in 3 patients. Conclusions For the first time, we present the results of genetic testing in IPAH patients from the Russian population. Despite the considerable heterogeneity in the world-wide data, the prevalence of pathogenic BMPR2 mutations in IPAH patients from the Russian population does not significantly differ from the overall average in the meta-analysis. It is crucial to periodically reassess the pathogenicity of published variants, as half of the pathogenic BMPR2 IPAH variants were reclassified as LP or of uncertain significance.
Penetrance of CHEK2 and BRCA1 Double Heterozygotes in Breast and/or Ovarian Cancer Patients
Germline pathogenic variants confer increased risk of breast and/or ovarian cancer. The penetrance of pathogenic variants is variable due to the effects of other genetic factors. The interaction between CHEK2 and BRCA1 proteins is crucial in homology directed DNA repair pathway. The aim of this study was to assess the effect of three pathogenic/likely pathogenic variants of the gene on pathogenic allelic variant penetrance. The analysis included 380 DNA samples of women with confirmed positive status for one of founder variants c.4035del and c.5266dup. The c.444+1G>A and c.470T>C variants of gene were identified by Sanger’s sequencing, and the del5395 variant was detected by multiplex PCR. The studied variants were found in 13 double heterozygous cases (c.444+1G>A, n = 1; c.470T>C, n = 11, del5395, n = 1). Although the prevalence of CHEK2 variants in the ovarian cancer group was comparatively high (5.41%), the increase of the ovarian cancer risk was not statistically significant (OR = 1.56; 95% CI: 0.32–9.94; p = 0.73). The association of the age at the onset of cancer with the presence of particular CHEK2 variant was not consistent.
Mainstream Germline Genetic Testing with Expanded Eligibility for Early Breast Cancer Patients in a Large Integrated Health System
Background This study evaluated a new mainstream genetic testing pathway for hereditary cancer, with expanded eligibility for early-stage breast cancer patients. Methods The study compared multigene panel (62 genes) germline testing uptake and results for breast cancer patients at 4 pilot sites ( n = 502 patients) and 10 non-pilot sites ( n = 1792 patients) within Kaiser Permanente Northern California from December 2020, to June 2021. At the pilot sites, breast care coordinators (BCCs) offered and consented patients for testing, with eligibility expanded to include all patients age 65 years or younger. At the non-pilot sites, eligible patients were referred to genetics for pre-test counseling, ordering, and follow-up evaluation with the standard guideline that included all patients age 45 years or younger. Results Demographic and disease characteristics were similar at the pilot and non-pilot sites. At the pilot verses non-pilot sites, a higher percentage of patients was tested overall (61.6% vs 31.7%) and across all age groups. The median time from breast biopsy to test result also was reduced (22 vs 33 days, respectively). A higher percentage of patients at the pilot sites was identified as having a pathogenic/likely pathogenic variant (PV/LPV) in a breast cancer-related gene (3.6% vs 1.6%). Although the percentage of total patients tested was nearly twofold higher at the pilot sites than at the non-pilot sites, the percentage of total patients seen by genetics was estimated to be similar (33.7% vs 31.7%). Conclusion Mainstream genetic testing of breast cancer patients facilitated by BCCs makes it feasible for a large health care system to expand germline genetic testing to early breast cancer patients age 65 years or younger.
Prevalence and spectrum of MLH1, MSH2, and MSH6 pathogenic germline variants in Pakistani colorectal cancer patients
Background Pathogenic germline variants in MLH1 , MSH2 and MSH6 genes account for the majority of Lynch syndrome (LS). In this first report from Pakistan, we investigated the prevalence of pathogenic MLH1/MSH2/MSH6 variants in colorectal cancer (CRC) patients. Methods Consecutive cases ( n  = 212) were recruited at the Shaukat Khanum Memorial Cancer Hospital and Research Centre (SKMCH&RC), between November 2007 to March 2011. Patients with a family history of >  3 or 2 HNPCC-associated cancers were classified as HNPCC ( n  = 9) or suspected-HNPCC ( n  = 20), respectively (group 1; n  = 29). Cases with no family history were designated as non-HNPCC (group 2; n  = 183). MLH1/MSH2/MSH6 genes were comprehensively screened in group 1. Pathogenic/likely pathogenic variants identified in group 1 were subsequently evaluated in group 2. Results Eight distinct pathogenic/likely pathogenic MLH1/MSH2 variants were found in group 1 (10/29; 34.5%), belonging to HNPCC (5/9; 55.6%) and suspected-HNPCC (5/20; 25%) families and in group 2 (2/183; 1.1%) belonging to non-HNPCC. Overall, three recurrent variants ( MSH2 c.943-1G > C, MLH1 c.1358dup and c.2041G > A) accounted for 58.3% (7/12) of all families harboring pathogenic/likely pathogenic MLH1/MSH2 variants. Pathogenic MSH6 variants were not detected. Conclusion Pathogenic/likely pathogenic MLH1/MSH2 variants account for a substantial proportion of CRC patients with HNPCC/suspected-HNPCC in Pakistan. Our findings suggest that HNPCC/suspected-HNPCC families should be tested for these recurrent variants prior to comprehensive gene screening in this population.
A pathogenic variant in the transforming growth factor beta I ( TGFBI ) in four Iranian extended families segregating granular corneal dystrophy type II: A literature review
Granular and lattice corneal dystrophies (GCDs & LCDs) are autosomal dominant inherited disorders of the cornea. Due to genetic heterogeneity and large genes, unraveling the mutation is challenging. Patients underwent comprehensive clinical examination, and targeted next-generation sequencing (NGS) was used for mutation detection. Co-segregation and analysis was accomplished. Patients suffered from GCD. NGS disclosed a known pathogenic variant, c.371G>A (p.R124H), in exon 4 of . The variant co-segregated with the phenotype in the family. Homozygous patients manifested with more severe phenotypes. Variable expressivity was observed among heterozygous patients. The results, in accordance with previous studies, indicate that the c.371G>A in TGFBI is associated with GCD. Some phenotypic variations are related to factors such as modifier genes, reduced penetrance and environmental effects.