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Fulltext FGFR3 mutation increases bladder tumourigenesis by suppressing acute inflammation

Foth M, Ismail NFB, Kung JSC, Tomlinson D, Knowles MA, Eriksson P, et al.

J Pathol, 2018 Nov;246(3):331-343.
PMID: 30043421 DOI: 10.1002/path.5143

Recent studies of muscle-invasive bladder cancer show that FGFR3 mutations are generally found in a luminal papillary tumour subtype that is characterised by better survival than other molecular subtypes. To better understand the role of FGFR3 in invasive bladder cancer, we examined the process of tumour development induced by the tobacco carcinogen OH-BBN in genetically engineered models that express mutationally activated FGFR3 S249C or FGFR3 K644E in the urothelium. Both occurrence and progression of OH-BBN-driven tumours were increased in the presence of an S249C mutation compared to wild-type control mice. Interestingly, at an early tumour initiation stage, the acute inflammatory response in OH-BBN-treated bladders was suppressed in the presence of an S249C mutation. However, at later stages of tumour progression, increased inflammation was observed in S249C tumours, long after the carcinogen administration had ceased. Early-phase neutrophil depletion using an anti-Ly6G monoclonal antibody resulted in an increased neutrophil-to-lymphocyte ratio at later stages of pathogenesis, indicative of enhanced tumour pathogenesis, which supports the hypothesis that suppression of acute inflammation could play a causative role. Statistical analyses of correlation showed that while initial bladder phenotypes in morphology and inflammation were FGFR3-dependent, increased levels of inflammation were associated with tumour progression at the later stage. This study provides a novel insight into the tumour-promoting effect of FGFR3 mutations via regulation of inflammation at the pre-tumour stage in the bladder. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Matched MeSH terms: Mutation
Fulltext Development and validation of high resolution melting assays for high-throughput screening of BDNF rs6265 and DAT1 rs40184

Asraa Faris, Hadri Hadi Md Yusof, Shahidee Zainal Abidin, Omar Habib, Cheah, Pike-See, Stanslas, Johnson, et al.

Malaysian Journal of Medicine and Health Sciences, 2018;14(101):64-71.
MyJurnal

Introduction: One of the commonly used techniques for mutation screening is High Resolution Melting (HRM) analysis. HRM is a post PCR method that relies on the detection of the fluorescent signals acquired due to the release of DNA intercalated dyes upon the melting of dsDNA to ssDNA. The method is simple, inexpensive and does not require post PCR-handling, making it suitable for high throughput screening. Methods: This study aimed to develop and validate HRM technique for the screening of two disease-associated single nucleotide polymorphisms (SNPs) namely BDNF rs6265 and DAT1 rs40184 using a total of 30 gDNA samples. The obtained results were confirmed and validated by sequencing. Results: HRM analysis showed that the predicted genotypes of BDNF rs6265 and DAT1 rs40184 among all the gDNA samples were in 100% concordance with the sequencing results, making it an accurate and sensitive method for the detection of SNPs. Conclusions: The application of HRM can accurately determine the genotype of BDNF rs6265 and DAT1 rs40184 SNPs, making it a promising tool for rapid and high-throughput screening of targeted SNPs in a large population study.

Matched MeSH terms: Mutation
Fulltext Enhancement of a protocol purifying T1 lipase through molecular approach

Che Hussian CHA, Raja Abd Rahman RNZ, Thean Chor AL, Salleh AB, Mohamad Ali MS

PeerJ, 2018;6:e5833.
PMID: 30479887 DOI: 10.7717/peerj.5833

T1 Lipase is a thermostable secretary protein of Geobacillus zalihae strain previously expressed in a prokaryotic system and purified using three-step purification: affinity 1, affinity 2, and ion exchange chromatography (IEX). This approach is time consuming and offers low purity and recovery yield. In order to enhance the purification strategy of T1 lipase, affinity 2 was removed so that after affinity 1, the cleaved Glutathione S-transferase (GST) and matured T1 lipase could be directly separated through IEX. Therefore, a rational design of GST isoelectric point (pI) was implemented by prediction using ExPASy software in order to enhance the differences of pI values between GST and matured T1 lipase. Site-directed mutagenesis at two locations flanking the downstream region of GST sequences (H215R and G213R) was successfully performed. Double point mutations changed the charge on GST from 6.10 to 6.53. The purified lipase from the new construct GST tag mutant-T1 was successfully purified using two steps of purification with 6,849 U/mg of lipase specific activity, 33% yield, and a 44-fold increase in purification. Hence, the increment of the pI values in the GST tag fusion T1 lipase resulted in a successful direct separation through IEX and lead to successful purification.

Matched MeSH terms: Point Mutation
Fulltext Complete genome sequence of fowl adenovirus-8b UPM04217 isolate associated with the inclusion body hepatitis disease in commercial broiler chickens in Malaysia reveals intermediate evolution

Mat Isa N, Mohd Ayob J, Ravi S, Mustapha NA, Ashari KS, Bejo MH, et al.

Virusdisease, 2019 Sep;30(3):426-432.
PMID: 31803810 DOI: 10.1007/s13337-019-00530-9

The main aim of our study was to explore the genome sequence of the inclusion body hepatitis associated Fowl adenovirus serotype 8b (FAdV-8b) UPM04217 and to study its genomic organisation. The nucleotide sequence of the whole genome of FAdV-8b UPM04217 was determined by using the 454 Pyrosequencing platform and the Sanger sequencing method. The complete genome was found to be 44,059 bp long with 57.9% G + C content and shared 97.5% genome identity with the reference FAdV-E genome (HG isolate). Interestingly, the genome analysis using ORF Finder, Glimmer3 and FGENESV predicted a total of 39 open reading frames (ORFs) compared to the FAdV-E HG that possessed 46 ORFs. Fourteen ORFs located within the central genomic region and 16 ORFs located within the left and right ends of the genome were assigned as being the high protein-coding regions. The fusion of the small ORFs at the right end terminal specifically in ORF22 and ORF33 could be the result of gene truncation in the FAdV-E HG. The frame shift mutation in ORF25 and other mutations in ORF13 and ORF17 might have lead to the emergence of genes that could have different functions. Besides, one of the minor capsid components, pVI, in FAdV-8b UPM04217 shared the highest similarity of 93% with that of FAdV-D, while only 47% similarity was found with FAdV-E. From the gene arrangement layout of the FAdV genome, FAdV-8b UPM04217 showed intermediate evolution between the FAdV-E HG and the FAdV-D although it was apparently more similar to the FAdV-E HG.

Matched MeSH terms: Frameshift Mutation
Tigecycline resistance may be associated with dysregulated response to stress in Mycobacterium abscessus

Ng HF, Ngeow YF, Yap SF, Zin T, Tan JL

Int J Med Microbiol, 2019 Nov 18.
PMID: 31784213 DOI: 10.1016/j.ijmm.2019.151380

Previously, we characterized 7C, a laboratory-derived tigecycline-resistant mutant of Mycobacterium abscessus ATCC 19977, and found that the resistance was conferred by a mutation in MAB_3542c, which encodes an RshA-like protein. In M. tuberculosis, RshA is an anti-sigma factor that negatively regulates the SigH-dependent heat/oxidative stress response. We hypothesized that this mutation in 7C might dysregulate the stress response which has been generally linked to antibiotic resistance. In this study, we tested this hypothesis by subjecting 7C to transcriptomic dissection using RNA sequencing. We found an over-expression of genes encoding the SigH ortholog, chaperones and oxidoreductases. In line with these findings, 7C demonstrated better survival against heat shock when compared to the wild-type ATCC 19977. Another interesting observation from the RNA-Seq analysis was the down-regulation of ribosomal protein-encoding genes. This highlights the possibility of ribosomal conformation changes which could negatively affect the binding of tigecycline to its target, leading to phenotypic resistance. We also demonstrated that transient resistance to tigecycline could be induced in the ATCC 19977 by elevated temperature. Taken together, these findings suggest that dysregulated stress response may be associated with tigecycline resistance in M. abscessus.

Matched MeSH terms: Mutation
An in vitro study to evaluate the genotoxicity of value added hydroxyapatite as a bone replacement material

Akram Hassan, Swaminathan D

Sains Malaysiana, 2011;40.

Hydroxyapatite (HA) used for bone replacement is one of the most active areas of ceramic biomaterials research currently. It has been used clinically for the last 20 years due to its excellent biocompatibility, osseoconduction and osseointegration. Many modifications have been done to develop a stronger, tougher and biocompatible ceramic biomaterial because pure HA is brittle. Researchers in Universiti Sains Malaysia had developed this value added HA that is stronger and less brittle compared to pure HA. The objective of this in vitro study was to evaluate the genotoxic characteristic of the value added HA based material by using Bacterial Reverse Mutation Assay (Ames test). The Bacterial Reverse Mutation Assay of HA was performed on Salmonella typhimurium strains TA98, TA100, TA1535, TA1537 and Escherichia coli strain WP2 uvrA using the preincubation method in the presence and absence of an exogenous metabolic activation system. All the bacterial tester strains treated with and without S9 Mix showed no increase of revertant colonies with increase in concentration of test substance for both the dose finding test and the main test. The number of revertant colonies was less than twice that of the solvent control for all the five bacterial strains and this was reproducible for both the dose finding test and the main test. The numbers of revertant colonies in the negative and positive controls were within the background data of our laboratory. In conclusion the results of the tests showed that the value added HA was considered to have no reverse mutagenic potential under the present test conditions.

Matched MeSH terms: Mutation
Fulltext Population structure and genetic diversity of Aedes aegypti and Aedes albopictus in Penang as revealed by mitochondrial DNA cytochrome oxidase I

Md Naim D, Kamal NZM, Mahboob S

Saudi J Biol Sci, 2020 Mar;27(3):953-967.
PMID: 32127775 DOI: 10.1016/j.sjbs.2020.01.021

The population genetics study is crucial as it helps in understanding the epidemiological aspects of dengue and help improving a vector control measures. This research aims to investigate the population genetics structure of two common species of Aedes mosquitoes in Penang; Aedes aegypti and Aedes albopictus using Cytochrome Oxidase I (COI) mitochondrial DNA (mtDNA) marker. Molecular investigations were derived from 440 bp and 418 bp mtDNA COI on 125 and 334 larvae of Aedes aegypti and Aedes albopictus respectively, from 32 locations in Penang. All samples were employed in the BLASTn for species identification. The haplotype diversity, nucleotide diversity, neutrality test and mismatch distribution analysis were conducted in DnaSP version 5.10.1. AMOVA analysis was conducted in ARLEQUIN version 3.5 and the phylogenetic reconstructions based on maximum likelihood (ML) and neighbor-joining (NJ) methods were implemented in MEGA X. The relationships among haplotypes were further tested by creating a minimum spanning tree using Network version 4.6.1. All samples were genetically identified and clustered into six distinct species. Among the species, Ae. albopictus was the most abundant (67.2%), followed by Ae. aegypti (25.2%) and the rest were counted for Culex sp. and Toxorhynchites sp. Both Ae. aegypti and Ae. albopictus show low nucleotide diversity (π) and high haplotype diversity (h), while the neutrality test shows a negative value in most of the population for both species. There are a total of 39 and 64 haplotypes recorded for Ae. aegypti and Ae. albopictus respectively. AMOVA analysis revealed that most of the variation occurred within population for both species. Mismatch distribution analysis showed bimodal characteristic of population differentiation for Ae. aegypti but Ae. albopictus showed unimodal characteristics of population differentiation. Genetic distance based on Tamura-Nei parameter showed low genetic divergent within population and high genetic divergent among population for both species. The maximum likelihood tree showed no obvious pattern of population genetic structure for both Ae. aegypti and Ae. albopictus from Penang and a moderate to high bootstrap values has supported this conclusion. The minimum spanning network for Ae. aegypti and Ae. albopictus showed five and three dominant haplotypes respectively, which indicates a mixture of haplotypes from the regions analysed. This study revealed that there is no population genetic structure exhibited by both Ae. aegypti and Ae. albopictus in Penang. Mutation has occurred rapidly in both species and this will be challenging in controlling the populations. However, further analysis needed to confirm this statement.

Matched MeSH terms: Mutation
Lafora disease in a Malaysian with a rare mutation in the EPM2A gene

Tee SK, Ong TL, Aris A, See SML, Leong HY, Khalid MKNM, et al.

Seizure, 2019 Apr;67:78-81.
PMID: 30947044 DOI: 10.1016/j.seizure.2019.03.012
Matched MeSH terms: Mutation, Missense
V1016G Point Mutation: The Key Mutation in the Voltage-Gated Sodium Channel (Vgsc) Gene of Pyrethroid-Resistant Aedes aegypti (Diptera: Culicidae) in Indonesia

Amelia-Yap ZH, Sofian-Azirun M, Chen CD, Lau KW, Suana IW, Syahputra E, et al.

J Med Entomol, 2019 06 27;56(4):953-958.
PMID: 30942885 DOI: 10.1093/jme/tjz035

Resistance to pyrethroid insecticides is widespread in Indonesian Aedes aegypti (Linnaeus), the primary vector of dengue viruses. This study aims to investigate the mutations in the voltage-gated sodium channel (Vgsc) conferring pyrethroid resistance against Ae. aegypti populations from Indonesia. Molecular genotyping of mutations using polymerase chain reaction assay and direct DNA sequencing were performed at positions 989 and 1,016 in IIS6 region, and 1,534 in IIIS6 region of the voltage-gated sodium channel (Vgsc) in nine populations of Indonesian Ae. aegypti. The V1016G and S989P genotyping identified the RR genotype to be predominant in six out of nine populations of Ae. aegypti, whereas the SS genotype occurred only in minority. Interestingly, co-occurrence of the V1016G and S989P mutations was detected in the aforementioned six populations with high frequency. Genotyping of F1534C showed all nine populations exhibited the SS genotype, with merely two individuals from a population were heterozygous (RS). Significant correlations were demonstrated between the allele frequencies of the V1016G mutation and the survivability rates as well as resistance ratios in pyrethroid adult bioassays. This signifies the V1016G can contribute more to the insensitivity of Vgsc than the F1534C. Homozygous 1016G mosquitoes were likelier to survive pyrethroid exposure. Identification of underlying mechanisms resulting in insecticide resistance is advantageous in developing effective mosquito control programs in Indonesia.

Matched MeSH terms: Point Mutation
Fulltext A 23 bp cyp51A Promoter Deletion Associated With Voriconazole Resistance in Clinical and Environmental Isolates of Neocosmospora keratoplastica

James JE, Lamping E, Santhanam J, Milne TJ, Abd Razak MF, Zakaria L, et al.

Front Microbiol, 2020;11:272.
PMID: 32296397 DOI: 10.3389/fmicb.2020.00272

In the fungal pathogen Aspergillus fumigatus, resistance to azole antifungals is often linked to mutations in CYP51A, a gene that encodes the azole antifungal drug target lanosterol 14α-demethylase. The aim of this study was to investigate whether similar changes could be associated with azole resistance in a Malaysian Fusarium solani species complex (FSSC) isolate collection. Most (11 of 15) clinical FSSC isolates were Neocosmospora keratoplastica and the majority (6 of 10) of environmental isolates were Neocosmospora suttoniana strains. All 25 FSSC isolates had high minimum inhibitory concentrations (MICs) for itraconazole and posaconazole, low MICs for amphotericin B, and various (1 to >32 mg/l) voriconazole susceptibilities. There was a tight association between a 23 bp CYP51A promoter deletion and high (>32 mg/l) voriconazole MICs; of 19 FSSC strains sequenced, nine isolates had voriconazole MICs > 32 mg/l, and they all contained the 23 bp CYP51A promoter deletion, although it was absent in the ten remaining isolates with low (≤12 mg/l) voriconazole MICs. Surprisingly, this association between voriconazole resistance and the 23 bp CYP51A promoter deletion held true across species boundaries. It was randomly distributed within and across species boundaries and both types of FSSC isolates were found among environmental and clinical isolates. Three randomly selected N. keratoplastica isolates with low (≤8 mg/l) voriconazole MICs had significantly lower (1.3-7.5 times) CYP51A mRNA expression levels than three randomly selected N. keratoplastica isolates with high (>32 mg/l) voriconazole MICs. CYP51A expression levels, however, were equally strongly induced (~6,500-fold) by voriconazole in two representative strains reaching levels, after 80 min of induction, that were comparable to those of CYP51B. Our results suggest that FSSC isolates with high voriconazole MICs have a 23 bp CYP51A promoter deletion that provides a potentially useful marker for voriconazole resistance in FSSC isolates. Early detection of possible voriconazole resistance is critical for choosing the correct treatment option for patients with invasive fusariosis.

Matched MeSH terms: Mutation
Fulltext A brief review on ACE I/D gene polymorphism and blood pressure response to exercise training

Hazwani Ahmad Yusof, Abdul Rashid Aziz, Nor Farah Mohamad Fauzi, Ahmad Munir Che Muhamed

Malaysian Journal of Medicine and Health Sciences, 2018;14(201):179-189.
MyJurnal

Exercise has been suggested as the best and the most affordable way for managing blood pressure. The insertion/ deletion of angiotensin I-converting enzyme (ACE) I/D gene polymorphism had been reported to be linked with sev- eral diseases such as hypertension and diabetic nephropathy. Several studies showed that blood pressure response to exercise training for health management also vary among individuals with different genotypes of ACE I/D gene poly- morphism. A study of 9 months of endurance exercise training at 75 to 85 % of VO2max showed that the decrease of resting blood pressure in I allele carriers wass greater than D allele carriers. In contrast, other study discovered that adult women with D allele had greater reduction in resting blood pressure than those with I allele, following a 12-week combined aerobic and resistance exercise training. Despite the inconsistencies of some findings, it has remained unknown if the ACE I/D gene polymorphism would also influence blood pressure response to isometric handgrip training that had been found to be superior to the dynamic resistance exercise training in controlling and preventing high blood pressure. Thus, this article was to review the literature on ACE I/D gene polymorphism and blood pressure response to exercise training that could serve as the basis for future research to identify individuals who will lower resting blood pressure the most with exercise training program for health management.

Matched MeSH terms: INDEL Mutation
Genetic diversity and in silico evidence of target-site mutation in the EPSPS gene in endowing glyphosate resistance in Eleusine indica (L.) from Malaysia

Franci J, Lam KW, Chuah TS, Cha TS

Pestic Biochem Physiol, 2020 May;165:104556.
PMID: 32359543 DOI: 10.1016/j.pestbp.2020.104556

Glyphosate-resistant populations of Eleusine indica are widespread in several states of Malaysia. A whole-plant bioassay confirmed that eight out of the 17 populations tested were resistant to glyphosate at double the recommended rate of 2.44 kg ha-1. Screening with allele-specific PCR (AS-PCR) revealed that resistant plants contained an EPSPS gene with either the homozygous S/S-106 or the heterozygous P/S-106 alleles. All susceptible plants contained only the homozygous P/P-106 allele. In addition, DNA sequences of the full-length EPSPS gene from one susceptible (SB) and four resistant (R2, R6, R8 and R11) populations revealed an amino acid substitution of T102I in all the resistant plants, while another substitution of P381L was only found in resistant populations R6 and R11. The significance of the P381L mutation was examined by Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) and residue interaction network (RIN) analyses, which suggests the P381L mutation may contribute to resistance. Mutations at 102 and 106 occur widely in the EPSPS gene of glyphosate-resistant E. indica populations from Malaysia with the TIPS mutation. In addition, the P381L mutation could also contribute to resistance.

Matched MeSH terms: Mutation
Fulltext Genome sequence analysis of multidrug-resistant Mycobacterium tuberculosis from Malaysia

Tan JL, Simbun A, Chan KG, Ngeow YF

Sci Data, 2020 05 05;7(1):135.
PMID: 32371951 DOI: 10.1038/s41597-020-0475-x

Mycobacterium tuberculosis (MTB) is commonly used as a model to study pathogenicity and multiple drug resistance in bacteria. These MTB characteristics are highly dependent on the evolution and phylogeography of the bacterium. In this paper, we describe 15 new genomes of multidrug-resistant MTB (MDRTB) from Malaysia. The assessments and annotations on the genome assemblies suggest that strain differences are due to lineages and horizontal gene transfer during the course of evolution. The genomes show mutations listed in current drug resistance databases and global MTB collections. This genome data will augment existing information available for comparative genomic studies to understand MTB drug resistance mechanisms and evolution.

Matched MeSH terms: Mutation
Fulltext Draft genome sequencing data of a pathogenic Pantoea stewartii subspecies stewartii strain SQT1 causing bronzing disease of jackfruit in Malaysia

Ibrahim R, Ismail-Suhaimy NW, Shu-Qing T, Ismail SI, Ina-Salwany MY, Yusof MT, et al.

Data Brief, 2020 Jun;30:105634.
PMID: 32395592 DOI: 10.1016/j.dib.2020.105634

A Gram-negative bacterium, Pantoea stewartii subspecies stewartii (P. stewartii subsp. stewartii) has been recognized as the causative agent for jackfruit bronzing disease in Malaysia. Here, we report the whole genome sequencing dataset of P. stewartii subsp. stewartii strain SQT1 isolated from local infected jackfruit. The paired-end libraries with an insert size of 350 bp was subjected to the Illumina Hiseq 4000, generating a genome size of 4,783,993 bp with a G+C content of 53.7%. A total protein of 4,671 was identified including virulence factors, resistance factors and secretion systems. Pantoea stewartii subsp. stewartii strain DC283 (NCBI accession no. CP017581.1) was used as a reference genome, where the query hit 72% coverage and average sequencing depth of 68. In total, 28,717 nucleotide polymorphisms, 520 small insertion/deletions and 142 structure variants were identified. The complete genome was deposited at the European Nucleotide Archive under the sample accession number ERP119356 and study accession number PRJEB36196.

Matched MeSH terms: INDEL Mutation
Fulltext Polycythaemia Vera JAK 2 Mutation in a Patient with Underlying Chronic Obstructive Pulmonary Disease at a Primary Care Setting

Mahmud R, Ariffin F, Shanmuganathan P

Korean J Fam Med, 2020 Jul;41(4):263-266.
PMID: 32512984 DOI: 10.4082/kjfm.18.0161

The presence of erythrocytosis along with the diagnosis of chronic obstructive pulmonary disease (COPD) may veer a primary care clinician in a busy clinic towards attributing the erythrocytosis to hypoxia secondary to COPD; however, this is not always the case. This case highlights the importance of investigation and the significance not excluding a primary cause in COPD patients with erythrocytosis. A 57-year-old male, presenting with chronic cough, was subsequently diagnosed with COPD clinically and confirmed by spirometry. Erythrocytosis was also incidentally noted. The patient did not have any symptoms of polycythemia or hepatosplenomegaly. Therefore, the erythrocytosis was initially thought to be caused by hypoxia secondary to COPD. However, the JAK2 V617F gene mutation was detected and hence the diagnosis of polycythemia vera was made. Although the erythrocytosis was initially attributed secondary to the underlying pulmonary disease, investigations proved it to be primary in origin. This case report highlights the importance of investigating the underlying cause and to confirm the diagnosis of erythrocytosis as primary and secondary polycythemia differ in their management approach. This will avoid inappropriate diagnosis, treatment, and undesirable outcomes.

Matched MeSH terms: Mutation
Fulltext Time series prediction of COVID-19 by mutation rate analysis using recurrent neural network-based LSTM model

Pathan RK, Biswas M, Khandaker MU

Chaos Solitons Fractals, 2020 Sep;138:110018.
PMID: 32565626 DOI: 10.1016/j.chaos.2020.110018

SARS-CoV-2, a novel coronavirus mostly known as COVID-19 has created a global pandemic. The world is now immobilized by this infectious RNA virus. As of June 15, already more than 7.9 million people have been infected and 432k people died. This RNA virus has the ability to do the mutation in the human body. Accurate determination of mutation rates is essential to comprehend the evolution of this virus and to determine the risk of emergent infectious disease. This study explores the mutation rate of the whole genomic sequence gathered from the patient's dataset of different countries. The collected dataset is processed to determine the nucleotide mutation and codon mutation separately. Furthermore, based on the size of the dataset, the determined mutation rate is categorized for four different regions: China, Australia, the United States, and the rest of the World. It has been found that a huge amount of Thymine (T) and Adenine (A) are mutated to other nucleotides for all regions, but codons are not frequently mutating like nucleotides. A recurrent neural network-based Long Short Term Memory (LSTM) model has been applied to predict the future mutation rate of this virus. The LSTM model gives Root Mean Square Error (RMSE) of 0.06 in testing and 0.04 in training, which is an optimized value. Using this train and testing process, the nucleotide mutation rate of 400th patient in future time has been predicted. About 0.1% increment in mutation rate is found for mutating of nucleotides from T to C and G, C to G and G to T. While a decrement of 0.1% is seen for mutating of T to A, and A to C. It is found that this model can be used to predict day basis mutation rates if more patient data is available in updated time.

Matched MeSH terms: Mutation Rate
Fulltext A review of colorectal cancer research in Malaysia

Lim KG

Med J Malaysia, 2014 Aug;69 Suppl A:23-32.
PMID: 25417948 MyJurnal

105 articles related to colorectal cancer(CRC) were found in a search through a database dedicated to indexing all original data relevant to medicine published in Malaysia between the years 2000-2013. 56 articles were selected and reviewed on the basis of clinical relevance and future research implications. Research into the genetic basis for colorectal cancer included studies in germline mutations of known syndromes as well as polymorphisms that conferred individuals a higher odds ratio for developing CRC. Several studies also documented the variety of somatic mutations seen in cases of sporadic CRC in Malaysia. Studies into the knowledge and attitudes of Malaysians regarding CRC revealed poor appreciation of the common symptoms, risk factors and available measures for its early detection. This may explain the observed facts that more Malaysians present with late stage CRC than seen in developed countries. The small amount of data recorded concerning the outcome of treatment also suggests overall survival of Malaysian CRC patients for comparable stage of CRC is lower than achieved in developed countries.

Matched MeSH terms: Germ-Line Mutation
Fulltext Polygenic risk scores and breast and epithelial ovarian cancer risks for carriers of BRCA1 and BRCA2 pathogenic variants

Barnes DR, Rookus MA, McGuffog L, Leslie G, Mooij TM, Dennis J, et al.

Genet Med, 2020 10;22(10):1653-1666.
PMID: 32665703 DOI: 10.1038/s41436-020-0862-x

PURPOSE: We assessed the associations between population-based polygenic risk scores (PRS) for breast (BC) or epithelial ovarian cancer (EOC) with cancer risks for BRCA1 and BRCA2 pathogenic variant carriers.
METHODS: Retrospective cohort data on 18,935 BRCA1 and 12,339 BRCA2 female pathogenic variant carriers of European ancestry were available. Three versions of a 313 single-nucleotide polymorphism (SNP) BC PRS were evaluated based on whether they predict overall, estrogen receptor (ER)-negative, or ER-positive BC, and two PRS for overall or high-grade serous EOC. Associations were validated in a prospective cohort.
RESULTS: The ER-negative PRS showed the strongest association with BC risk for BRCA1 carriers (hazard ratio [HR] per standard deviation = 1.29 [95% CI 1.25-1.33], P = 3×10-72). For BRCA2, the strongest association was with overall BC PRS (HR = 1.31 [95% CI 1.27-1.36], P = 7×10-50). HR estimates decreased significantly with age and there was evidence for differences in associations by predicted variant effects on protein expression. The HR estimates were smaller than general population estimates. The high-grade serous PRS yielded the strongest associations with EOC risk for BRCA1 (HR = 1.32 [95% CI 1.25-1.40], P = 3×10-22) and BRCA2 (HR = 1.44 [95% CI 1.30-1.60], P = 4×10-12) carriers. The associations in the prospective cohort were similar.
CONCLUSION: Population-based PRS are strongly associated with BC and EOC risks for BRCA1/2 carriers and predict substantial absolute risk differences for women at PRS distribution extremes.

Matched MeSH terms: Mutation
Fulltext Revealing hidden genetic diagnoses in the ocular anterior segment disorders

Ma A, Yousoof S, Grigg JR, Flaherty M, Minoche AE, Cowley MJ, et al.

Genet Med, 2020 10;22(10):1623-1632.
PMID: 32499604 DOI: 10.1038/s41436-020-0854-x

PURPOSE: Ocular anterior segment disorders (ASDs) are clinically and genetically heterogeneous, and genetic diagnosis often remains elusive. In this study, we demonstrate the value of a combined analysis protocol using phenotypic, genomic, and pedigree structure data to achieve a genetic conclusion.
METHODS: We utilized a combination of chromosome microarray, exome sequencing, and genome sequencing with structural variant and trio analysis to investigate a cohort of 41 predominantly sporadic cases.
RESULTS: We identified likely causative variants in 54% (22/41) of cases, including 51% (19/37) of sporadic cases and 75% (3/4) of cases initially referred as familial ASD. Two-thirds of sporadic cases were found to have heterozygous variants, which in most cases were de novo. Approximately one-third (7/22) of genetic diagnoses were found in rarely reported or recently identified ASD genes including PXDN, GJA8, COL4A1, ITPR1, CPAMD8, as well as the new phenotypic association of Axenfeld-Rieger anomaly with a homozygous ADAMTS17 variant. The remainder of the variants were in key ASD genes including FOXC1, PITX2, CYP1B1, FOXE3, and PAX6.
CONCLUSIONS: We demonstrate the benefit of detailed phenotypic, genomic, variant, and segregation analysis to uncover some of the previously "hidden" heritable answers in several rarely reported and newly identified ocular ASD-related disease genes.

Matched MeSH terms: Mutation
Fulltext Hemoglobin A2 and Heterogeneous Diagnostic Relevance Observed in Eight New Variants of the Delta Globin Gene

Mahmud N, Maffei M, Mogni M, Forni GL, Pinto VM, Barberio G, et al.

Genes (Basel), 2021 11 19;12(11).
PMID: 34828427 DOI: 10.3390/genes12111821

BACKGROUND: Hemoglobin A (Hb A) (α2β2) in the normal adult subject constitutes 96-98% of hemoglobin, and Hb F is normally less than 1%, while for hemoglobin A2 (Hb A2) (α2δ2), the normal reference values are between 2.0 and 3.3%. It is important to evaluate the presence of possible delta gene mutations in a population at high risk for globin gene defects in order to correctly diagnose the β-thalassemia carrier.
METHODS: The most used methods for the quantification of Hb A2 are based on automated high performance liquid chromatography (HPLC) or capillary electrophoresis (CE). In particular Hb analyses were performed by HPLC on three dedicated devices. DNA analyses were performed according to local standard protocols.
RESULTS: Here, we described eight new δ-globin gene variants discovered and characterized in some laboratories in Northern Italy in recent years. These new variants were added to the many already known Hb A2 variants that were found with an estimated frequency of about 1-2% during the screening tests in our laboratories.
CONCLUSIONS: The knowledge recognition of the delta variant on Hb analysis and accurate molecular characterization is crucial to provide an accurate definitive thalassemia diagnosis, particularly in young subjects who would like to ask for a prenatal diagnosis or preimplantation genetic diagnosis.

Matched MeSH terms: Mutation

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