Understanding the prevalence of soil-transmitted helminth infections is necessary to plan control strategies and focus on highly endemic regions for preventive chemotherapy and improved sanitation ...facilities. India is known to be endemic for soil-transmitted helminth infections.
To understand the prevalence, spatial distribution and identify high-risk zones, a systematic search of published literature was carried out based on PRISMA guidelines from the year 2000 to 2015.
A careful screening of the identified literature yielded 39 studies that reported the prevalence of soil-transmitted helminth infections from 19 different states of India. Ascaris lumbricoides was the most prevalent parasite. Higher than 50% prevalence was reported from six states. Nearly 90% studies reported the prevalence of more than one parasite species in the same sample population.
This is the first study to comprehensively review the literature associated with soil-transmitted helminth infections from India giving a clear idea of its prevalence, distribution and high endemic areas.
High-grade serous ovarian carcinoma (HGSOC) is the most frequent type of ovarian carcinoma, associated with poor clinical outcome and metastatic disease. Although metastatic processes are becoming ...more understandable, the genomic landscape and metastatic progression in HGSOC has not been elucidated.
Multi-region whole-exome sequencing was performed on HGSOC primary tumours and their metastases (n = 33 tumour regions) from six patients. The resulting somatic variants were analysed to delineate tumour evolution and metastatic dissemination, and to compare the repertoire of events between primary HGSOC and metastasis.
All cases presented branching evolution patterns in primary HGSOC, with three cases further showing parallel evolution in which different mutations on separate branches of a phylogenetic tree converge on the same gene. Furthermore, linear metastatic progression was observed in 67% of cases with late dissemination, in which the metastatic tumour mostly acquires the same mutational process active in primary tumour, and parallel metastatic progression, with early dissemination in the remaining 33.3% of cases. Metastatic-specific SNVs were further confirmed as late dissemination events. We also found the involvement of metastatic-specific driver events in the Wnt/β-catenin pathway, and identified potential clinically actionable events in individual patients of the metastatic HGSOC cohort.
This study provides deeper insights into clonal evolution and mutational processes that can pave the way to new therapeutic targets.
Breast cancer (BC) is the most prevalent malignancy among women worldwide with germline pathogenic variants/likely pathogenic variants (PVs/LPVs) in BRCA1/2 accounting for a large portion of ...hereditary cases. Recently, heterozygous PVs/LPVs in the ATM serine/threonine kinase or Ataxia-telangiectasia mutated gene (ATM) has been identified as a moderate susceptibility factor for BC in diverse ethnicities. However, the prevalence of ATM PVs/LPVs in BC susceptibility in Arab populations remains largely unexplored. This study investigated the prevalence of ATM PVs/LPVs among BC patients from Saudi Arabia, employing capture-sequencing technology for ATM PVs/LPVs screening in a cohort of 715 unselected BC patients without BRCA1/2 PVs/LPVs. In addition, founder mutation analysis was conducted using the PHASE program. In our entire cohort, four unique PVs/LPVs in the ATM gene were identified in six cases (0.8%). Notably, one recurrent LPV, c.6115G > A:p.Glu2039Lys was identified in three cases, for which haplotype analysis confirmed as a novel putative founder mutation traced back to 13 generations on average. This founder mutation accounted for half of all identified mutant cases and 0.4% of total screened cases. This study further reveals a significant correlation between the presence of ATM mutation and family history of BC (p = 0.0127). These findings underscore an approximate 0.8% prevalence of ATM germline PVs/LPVs in Arab BC patients without BRCA1/2 PVs/LPVs and suggest a founder effect of specific recurrent ATM mutation. These insights can help in the design of a genetic testing strategy tailored to the local population in Saudi Arabia, thereby, enabling more accurate clinical management and risk prediction.
Abstract
Mutation-induced activation of
Wnt
-β Catenin signaling pathway is frequent in CRC. The E3 ubiquitin ligase,
RNF43
, has been reported to negatively regulate the
Wnt
signaling pathway and
...RNF43
mutations are frequently seen in CRC. However, its role in Middle Eastern CRC remains unclear. Therefore, we employed Exome and Sanger sequencing technology to assess the frequency of
RNF43
mutations and its association with other clinico-pathological features in Middle Eastern CRC.
RNF43
mutations were found in 5.9% (13/220) of CRC cases and was inversely correlated to
APC
and
TP53
mutations. A strong association of
RNF43
mutations with right sided and sporadic microsatellite instable (MSI) CRC was observed. No association was identified between
RNF43
mutation and other clinico-pathological features including
BRAF
mutation, age, tumor histological subtype, tumor grade or patients’ prognosis. Multivariate logistic regression analysis revealed that MSI status and wild type
APC
were independent predictor of
RNF43
mutation. We conclude that
RNF43
mutations occur in Middle Eastern CRC at comparable frequencies with
BRAF
mutations and represent a distinct molecular subtype which further enhances our understanding of how different mutational subsets of
Wnt
tumor suppressor genes link to distinct tumor characteristics, which might be considered for treatment strategies for CRC patients.
The PALB2 gene is a breast cancer (BC) and ovarian cancer (OC) predisposition gene involved in the homologous recombination repair pathway. However, the prevalence and clinicopathological association ...of PALB2 pathogenic/likely pathogenic (PV/LPV) variants in Middle East is still not fully explored. Total 918 BC/OC patients from Saudi Arabia were selected for PALB2 mutations screening using capture sequencing technology. Five heterozygous PVs or LPVs were identified in six cases, accounting for 0.65% (6/918) of entire cohort. Two cases (33.3%) harbored PVs and four cases (66.7%) carried LPVs. Four PVs/LPVs (80%) were frameshift along with one novel splicing LPV (c.2835-2_2835-1delinsTT). One recurrent LPV (c.3425delT: p.L1142fs) was identified in two cases. All six affected carriers have breast cancer diagnosis with median age of 39.5 years (range 34-49 years). Only two cases (33%) have documented family history of cancer. Breast cancer phenotype was invasive ductal unilateral cancer in all cases with 66.7% of hormone receptor positive and 16% of triple negative tumors. Germline PVs/LPVs in the PALB2 gene were observed in low frequency of 0.65% in Saudi BC and/or OC. Our study confirms one recurrent LPV and one novel LPV in Saudi breast cancer patients.
Papillary thyroid carcinoma (PTC) is the commonest thyroid cancer. The majority of inherited causes of PTC remain elusive. However, understanding the genetic underpinnings and origins remains a ...challenging endeavor. An exome-wide association study was performed to identify rare germline variants in coding regions associated with PTC risk in the Middle Eastern population. By analyzing exome-sequencing data from 249 PTC patients (cases) and 1395 individuals without any known cancer (controls), GALNT9 emerged as being strongly associated with rare inactivating variants (RIVs) (4/249 cases vs. 1/1395 controls, OR = 22.75, p = 5.09 × 10−5). Furthermore, three genes, TRIM40, ARHGAP23, and SOX4, were enriched for rare damaging variants (RDVs) at the exome-wide threshold (p < 2.5 × 10−6). An additional seven genes (VARS1, ZBED9, PRRC2A, VWA7, TRIM31, TRIM40, and COL8A2) were associated with a Middle Eastern PTC risk based on the sequence kernel association test (SKAT). This study underscores the potential of GALNT9 and other implicated genes in PTC predisposition, illuminating the need for large collaborations and innovative approaches to understand the genetic heterogeneity of PTC predisposition.
Lynch syndrome (LS) is the most common cause of inherited endometrial cancer (EC). The prevalence and molecular characteristic of LS in Middle Eastern women with EC have been underexplored. To ...evaluate the frequency of LS in a cohort of EC patients from Saudi Arabia, a total of 436 EC cases were screened utilizing immunohistochemistry (IHC), MLH1 promoter methylation analysis and next-generation sequencing technology. A total of 53 of 436 (12.2%) ECs were classified as DNA mismatch repair-deficient (dMMR). MLH1 promoter hypermethylation was detected in 30 ECs (6.9%). Three ECs (0.7%) were found to be LS harboring germline pathogenic variants (PVs)/likely pathogenic variants (LPVs): two in the MSH2 gene and one in the MSH6 gene. Three ECs (0.7%) were Lynch-like syndrome (LLS) carrying double somatic MSH2 PVs/LPVs. Seven cases were found to have variants of uncertain significance in cancer-related genes other than MMR genes. Our results indicate that LS prevalence is low among Saudi EC patients and LLS is as common as LS in this ethnicity. Our findings could help in better understanding of the prevalence and mutational spectrum of this syndrome in Saudi Arabia, which may help in defining best strategies for LS identification, prevention and genetic counseling for EC patients.
Standard surgery followed by radioactive iodine (131I, RAI) therapy are not curative for 5−20% of papillary thyroid carcinoma (PTC) patients with RAI refractory disease. Early predictors indicating ...therapeutic response to RAI therapy in PTC are yet to be elucidated. Whole-exome sequencing was performed (at median depth 198x) on 66 RAI-refractory and 92 RAI-avid PTCs with patient-matched germline. RAI-refractory tumors were significantly associated with distinct aggressive clinicopathological features, including positive surgical margins (p = 0.016) and the presence of lymph node metastases at primary diagnosis (p = 0.012); higher nonsilent tumor mutation burden (p = 0.011); TERT promoter (TERTp) mutation (p < 0.0001); and the enrichment of the APOBEC-related single-base substitution (SBS) COSMIC mutational signatures 2 (p = 0.030) and 13 (p < 0.001). Notably, SBS13 (odds ratio OR 30.4, 95% confidence intervals CI 1.43−647.22) and TERTp mutation (OR 41.3, 95% CI 4.35−391.60) were revealed to be independent predictors of RAI refractoriness in PTC (p = 0.029 and 0.001, respectively). Although SBS13 and TERTp mutations alone highly predicted RAI refractoriness, when combined, they significantly increased the likelihood of predicting RAI refractoriness in PTC. This study highlights the APOBEC SBS13 mutational signature as a novel independent predictor of RAI refractoriness in a distinct subgroup of PTC.
Colorectal cancer (CRC) is the third most frequently diagnosed cancer worldwide, where ~50% of patients develop metastasis, despite current improved management. Genomic characterisation of metastatic ...CRC, and elucidating the effects of therapy on the metastatic process, are essential to help guide precision medicine. Multi-region whole-exome sequencing was performed on 191 sampled tumour regions of patient-matched therapy-naïve and treated CRC primary tumours (n = 92 tumour regions) and metastases (n = 99 tumour regions), in 30 patients. Somatic variants were analysed to define the origin, composition, and timing of seeding in the metastatic progression of therapy-naïve and treated metastatic CRC. High concordance, with few genomic differences, was observed between primary CRC and metastases. Most cases supported a late dissemination model, via either monoclonal or polyclonal seeding. Polyclonal seeding appeared more common in therapy-naïve metastases than in treated metastases. Whereby, treatment prompted for the selection of distinct resistant clones, through monoclonal seeding to distant metastatic sites. Overall, this study reinforces the importance of early clinical detection and surgical excision of the CRC tumour, whilst further highlighting the clinical challenges for metastatic CRC with increased intratumour heterogeneity (either due to early dissemination or polyclonal metastatic spread) and the underlying risk of future therapeutic resistance in treated patients.
Background: Adenocarcinoma, a subgroup of non-small cell lung cancer, is the most frequent form occurring in the non-smokers. Mutation in tyrosine kinase domain of epidermal growth factor receptor ...(EGFR) has been a common feature observed in lung adenocarcinoma. The study was carried out to detect the prevalence of EGFR mutation in lung adenocarcinoma. Materials and Methods: EGFR mutation status in 166 lung adenocarcinoma patients was obtained retrospectively. Mutation tests were performed on paraffin embedded tissue blocks as a routine diagnostic procedure by polymerase chain reaction followed by direct nucleotide sequencing. Patient′s demographics and other clinical details were obtained from the medical records. Results: EGFR mutation was detected in 43/166 (25.9%) patients. Gender wise mutation was observed as 18/55 (32.7%) in females and 25/111 (22.5%) in males. Overall, EGFR mutation was correlated with never smokers and distant metastasis ( P < 0.05), but not associated with the gender, disease stage and pleural effusion. Exon 19 deletions were significantly correlated with females, never smokers, pleural effusion and distant metastasis ( P < 0.05). However, point mutation on exon 21 did not show any statistical association with the above variables. Median overall survival was 22 months (95% confidence interval, 15.4-28.6). Female sex, EGFR mutation and absence of metastasis are associated with good prognosis. Conclusion: EGFR mutation in lung adenocarcinoma was higher in never smokers, females and patients with distant metastasis. However, it was not linked with tobacco smoking. The prevalence of EGFR mutation observed is in range with the previously published reports from the Asian countries.
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