Displaying publications 1 - 20 of 143 in total

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  1. Hakkaart C, Pearson JF, Marquart L, Dennis J, Wiggins GAR, Barnes DR, et al.
    Commun Biol, 2022 Oct 06;5(1):1061.
    PMID: 36203093 DOI: 10.1038/s42003-022-03978-6
    The contribution of germline copy number variants (CNVs) to risk of developing cancer in individuals with pathogenic BRCA1 or BRCA2 variants remains relatively unknown. We conducted the largest genome-wide analysis of CNVs in 15,342 BRCA1 and 10,740 BRCA2 pathogenic variant carriers. We used these results to prioritise a candidate breast cancer risk-modifier gene for laboratory analysis and biological validation. Notably, the HR for deletions in BRCA1 suggested an elevated breast cancer risk estimate (hazard ratio (HR) = 1.21), 95% confidence interval (95% CI = 1.09-1.35) compared with non-CNV pathogenic variants. In contrast, deletions overlapping SULT1A1 suggested a decreased breast cancer risk (HR = 0.73, 95% CI 0.59-0.91) in BRCA1 pathogenic variant carriers. Functional analyses of SULT1A1 showed that reduced mRNA expression in pathogenic BRCA1 variant cells was associated with reduced cellular proliferation and reduced DNA damage after treatment with DNA damaging agents. These data provide evidence that deleterious variants in BRCA1 plus SULT1A1 deletions contribute to variable breast cancer risk in BRCA1 carriers.
    Matched MeSH terms: Heterozygote
  2. Li S, Silvestri V, Leslie G, Rebbeck TR, Neuhausen SL, Hopper JL, et al.
    J Clin Oncol, 2022 May 10;40(14):1529-1541.
    PMID: 35077220 DOI: 10.1200/JCO.21.02112
    PURPOSE: To provide precise age-specific risk estimates of cancers other than female breast and ovarian cancers associated with pathogenic variants (PVs) in BRCA1 and BRCA2 for effective cancer risk management.

    METHODS: We used data from 3,184 BRCA1 and 2,157 BRCA2 families in the Consortium of Investigators of Modifiers of BRCA1/2 to estimate age-specific relative (RR) and absolute risks for 22 first primary cancer types adjusting for family ascertainment.

    RESULTS: BRCA1 PVs were associated with risks of male breast (RR = 4.30; 95% CI, 1.09 to 16.96), pancreatic (RR = 2.36; 95% CI, 1.51 to 3.68), and stomach (RR = 2.17; 95% CI, 1.25 to 3.77) cancers. Associations with colorectal and gallbladder cancers were also suggested. BRCA2 PVs were associated with risks of male breast (RR = 44.0; 95% CI, 21.3 to 90.9), stomach (RR = 3.69; 95% CI, 2.40 to 5.67), pancreatic (RR = 3.34; 95% CI, 2.21 to 5.06), and prostate (RR = 2.22; 95% CI, 1.63 to 3.03) cancers. The stomach cancer RR was higher for females than males (6.89 v 2.76; P = .04). The absolute risks to age 80 years ranged from 0.4% for male breast cancer to approximately 2.5% for pancreatic cancer for BRCA1 carriers and from approximately 2.5% for pancreatic cancer to 27% for prostate cancer for BRCA2 carriers.

    CONCLUSION: In addition to female breast and ovarian cancers, BRCA1 and BRCA2 PVs are associated with increased risks of male breast, pancreatic, stomach, and prostate (only BRCA2 PVs) cancers, but not with the risks of other previously suggested cancers. The estimated age-specific risks will refine cancer risk management in men and women with BRCA1/2 PVs.

    Matched MeSH terms: Heterozygote
  3. Sa'at H, Lee YK, Yoon SY, Wong SW, Woo YL, Barlow-Stewart K, et al.
    Int J Behav Med, 2022 Feb;29(1):1-13.
    PMID: 33791992 DOI: 10.1007/s12529-021-09984-y
    BACKGROUND: The uptake of risk-reducing salpingo-oophorectomy (RRSO) in Asian countries is variable despite being the most effective option for ovarian cancer risk reduction in BRCA mutation carriers. Exploration of factors which may impact the RRSO decision-making of BRCA mutation carriers from Malaysia, a developing country in Southeast Asia, was undertaken.

    METHODS: In-depth interviews with 28 Malaysian BRCA mutation carriers with a history of breast cancer were conducted in addition to observing their RRSO decision-making consultations in the clinic.

    RESULTS: The decision-making considerations among the carriers were centered around the overarching theme of "Negotiating cancer risk and womanhood priorities," with the following themes: (1) risk perception, (2) self-preservation, (3) motherhood obligation, and (4) the preciousness of marriage. Cognitive knowledge of BRCA risk was often conceptualized based on personal and family history of cancer, personal beliefs, and faith. Many women reported fears that RRSO would affect them physically and emotionally, worrying about the post-surgical impact on their motherhood responsibilities. Nevertheless, some reported feeling obliged to choose RRSO for the sake of their children. For some, their husband's support and approval were critical, with emotional well-being and sexuality reportedly perceived as important to sustaining married life. Despite reporting hesitancy toward RRSO, women's decisions about choosing this option evolved as their priorities changed at different stages of life.

    CONCLUSIONS: Recognizing during clinic encounters with Malaysian women that RRSO decision-making involves negotiating the likelihood of developing cancer with the societal priorities of being a woman, mother, and wife may serve to support their decision-making.

    Matched MeSH terms: Heterozygote
  4. Li T, Pappas C, Le ST, Wang Q, Klinedinst BS, Larsen BA, et al.
    Neurobiol Aging, 2022 Jan;109:158-165.
    PMID: 34740077 DOI: 10.1016/j.neurobiolaging.2021.09.020
    The Apolipoprotein E ε4 (APOE ε4) haplotype is the strongest genetic risk factor for late-onset Alzheimer's disease (AD). The Translocase of Outer Mitochondrial Membrane-40 (TOMM40) gene maintains cellular bioenergetics, which is disrupted in AD. TOMM40 rs2075650 ('650) G versus A carriage is consistently related to neural and cognitive outcomes, but it is unclear if and how it interacts with APOE. We examined 21 orthogonal neural networks among 8,222 middle-aged to aged participants in the UK Biobank cohort. ANOVA and multiple linear regression tested main effects and interactions with APOE and TOMM40 '650 genotypes, and if age and sex acted as moderators. APOE ε4 was associated with less strength in multiple networks, while '650 G versus A carriage was related to more language comprehension network strength. In APOE ε4 carriers, '650 G-carriage led to less network strength with increasing age, while in non-G-carriers this was only seen in women but not men. TOMM40 may shift what happens to network activity in aging APOE ε4 carriers depending on sex.
    Matched MeSH terms: Heterozygote
  5. Hall HN, Bengani H, Hufnagel RB, Damante G, Ansari M, Marsh JA, et al.
    PLoS One, 2022;17(11):e0268149.
    PMID: 36413568 DOI: 10.1371/journal.pone.0268149
    Classical aniridia is a congenital and progressive panocular disorder almost exclusively caused by heterozygous loss-of-function variants at the PAX6 locus. We report nine individuals from five families with severe aniridia and/or microphthalmia (with no detectable PAX6 mutation) with ultrarare monoallelic missense variants altering the Arg51 codon of MAB21L1. These mutations occurred de novo in 3/5 families, with the remaining families being compatible with autosomal dominant inheritance. Mice engineered to carry the p.Arg51Leu change showed a highly-penetrant optic disc anomaly in heterozygous animals with severe microphthalmia in homozygotes. Substitutions of the same codon (Arg51) in MAB21L2, a close homolog of MAB21L1, cause severe ocular and skeletal malformations in humans and mice. The predicted nucleotidyltransferase function of MAB21L1 could not be demonstrated using purified protein with a variety of nucleotide substrates and oligonucleotide activators. Induced expression of GFP-tagged wildtype and mutant MAB21L1 in human cells caused only modest transcriptional changes. Mass spectrometry of immunoprecipitated protein revealed that both mutant and wildtype MAB21L1 associate with transcription factors that are known regulators of PAX6 (MEIS1, MEIS2 and PBX1) and with poly(A) RNA binding proteins. Arg51 substitutions reduce the association of wild-type MAB21L1 with TBL1XR1, a component of the NCoR complex. We found limited evidence for mutation-specific interactions with MSI2/Musashi-2, an RNA-binding proteins with effects on many different developmental pathways. Given that biallelic loss-of-function variants in MAB21L1 result in a milder eye phenotype we suggest that Arg51-altering monoallelic variants most plausibly perturb eye development via a gain-of-function mechanism.
    Matched MeSH terms: Heterozygote
  6. Lakeman IMM, van den Broek AJ, Vos JAM, Barnes DR, Adlard J, Andrulis IL, et al.
    Genet Med, 2021 Sep;23(9):1726-1737.
    PMID: 34113011 DOI: 10.1038/s41436-021-01198-7
    PURPOSE: To evaluate the association between a previously published 313 variant-based breast cancer (BC) polygenic risk score (PRS313) and contralateral breast cancer (CBC) risk, in BRCA1 and BRCA2 pathogenic variant heterozygotes.

    METHODS: We included women of European ancestry with a prevalent first primary invasive BC (BRCA1 = 6,591 with 1,402 prevalent CBC cases; BRCA2 = 4,208 with 647 prevalent CBC cases) from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), a large international retrospective series. Cox regression analysis was performed to assess the association between overall and ER-specific PRS313 and CBC risk.

    RESULTS: For BRCA1 heterozygotes the estrogen receptor (ER)-negative PRS313 showed the largest association with CBC risk, hazard ratio (HR) per SD = 1.12, 95% confidence interval (CI) (1.06-1.18), C-index = 0.53; for BRCA2 heterozygotes, this was the ER-positive PRS313, HR = 1.15, 95% CI (1.07-1.25), C-index = 0.57. Adjusting for family history, age at diagnosis, treatment, or pathological characteristics for the first BC did not change association effect sizes. For women developing first BC 

    Matched MeSH terms: Heterozygote
  7. Wong YY, Alauddin H, Raja Sabudin RZA, Ithnin A, Jalil N, Abdul Latiff Z, et al.
    Malays J Pathol, 2021 Apr;43(1):95-100.
    PMID: 33903312
    The Siriraj I Gγ(Aγδβ)0-thalassaemia is a novel mutation involving a 118kb deletion of the β-globin gene cluster. It was first reported in 2012 in two unrelated families from the southern part of Thailand. The carriers in the heterozygous state are clinically asymptomatic. Nonetheless, its complex interaction with other β-thalassaemia could give rise to different clinical phenotypes, ranging from mild thalassaemia intermedia to thalassaemia major. We report here a case of a six-year-old Malay boy, presented with pallor, growth failure and hepatosplenomegaly. His haemoglobin at presentation was 9.2g/dL with a mean cell haemoglobin of 22.6pg and a mean cell volume of 69.9fl. His peripheral blood smear showed features of thalassaemia intermedia. Haemoglobin (Hb) analysis revealed markedly raised Hb F (83%), normal HbA2 levels and absent HbA. Deoxyribonucleic acid (DNA) analysis showed compound heterozygous IVS1-1 (G→T) β-globin gene mutation and Siriraj I Gγ(Aγδβ)0-deletion (genotype βIVS1-1/ β Siriraj I deletion). Both his father and elder sister are carriers of Siriraj I Gγ(Aγδβ)0-thalassaemia while his mother carries IVS1-1 (G→T) gene mutation. Clinically, the patient is transfusion dependent on six weekly regime. To the best of our knowledge, this is the first reported case in Malaysia involving unique Siriraj I Gγ(Aγδβ)0-thalassaemia and IVS1-1 (G→T) in a compound heterozygous state. In summary, detection of Siriraj I Gγ(Aγδβ)0-thalassaemia is essential as this deletion can lead to severe disease upon interaction with a β-thalassemia point mutation as demonstrated in our case. The establishment of effective carrier screening and genetic counselling is important to prevent its adverse consequences.
    Matched MeSH terms: Heterozygote
  8. Ismail SN, Ghani NSA, Ab Razak SF, Abidin RAZ, Mohd Yusof MF, Zubir MN, et al.
    Trop Life Sci Res, 2020 Oct;31(3):15-27.
    PMID: 33214853 DOI: 10.21315/tlsr2020.31.3.2
    Assessments of genetic diversity have been claimed to be significantly efficient in utilising and managing resources of genetic for breeding programme. In this study, variations in genetic were observed in 65 pineapple accessions gathered from germplasm available at Malaysian Agriculture Research and Development Institute (MARDI) located in Pontian, Johor via 15 markers of simple sequence repeat (SSR). The results showed that 59 alleles appeared to range from 2.0 to 6.0 alleles with a mean of 3.9 alleles per locus, thus displaying polymorphism for all samples at a moderate level. Furthermore, the values of polymorphic information content (PIC) had been found to range between 0.104 (TsuAC035) and 0.697 (Acom_9.9), thus averaging at the value of 0.433. In addition, the expected and the observed heterozygosity of each locus seemed to vary within the ranges of 0.033 to 0.712, and from 0.033 to 0.885, along with the average values of 0.437 and 0.511, respectively. The population structure analysis via method of delta K (ΔK), along with mean of L (K) method, revealed that individuals from the germplasm could be divided into two major clusters based on genetics (K = 2), namely Group 1 and Group 2. As such, five accessions (Yankee, SRK Chalok, SCK Giant India, SC KEW5 India and SC1 Thailand) were clustered in Group 1, while the rest were clustered in Group 2. These outcomes were also supported by the dendrogram, which had been generated through the technique of unweighted pair group with arithmetic mean (UPGMA). These analyses appear to be helpful amongst breeders to maintain and to manage their collections of germplasm. Besides, the data gathered in this study can be useful for breeders to exploit the area of genetic diversity in estimating the level of heterosis.
    Matched MeSH terms: Heterozygote
  9. 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: Heterozygote
  10. Tsai MH, Muir AM, Wang WJ, Kang YN, Yang KC, Chao NH, et al.
    Neuron, 2020 Apr 22;106(2):237-245.e8.
    PMID: 32097630 DOI: 10.1016/j.neuron.2020.01.027
    Lissencephaly (LIS), denoting a "smooth brain," is characterized by the absence of normal cerebral convolutions with abnormalities of cortical thickness. Pathogenic variants in over 20 genes are associated with LIS. The majority of posterior predominant LIS is caused by pathogenic variants in LIS1 (also known as PAFAH1B1), although a significant fraction remains without a known genetic etiology. We now implicate CEP85L as an important cause of posterior predominant LIS, identifying 13 individuals with rare, heterozygous CEP85L variants, including 2 families with autosomal dominant inheritance. We show that CEP85L is a centrosome protein localizing to the pericentriolar material, and knockdown of Cep85l causes a neuronal migration defect in mice. LIS1 also localizes to the centrosome, suggesting that this organelle is key to the mechanism of posterior predominant LIS.
    Matched MeSH terms: Heterozygote
  11. Hamanaka K, Imagawa E, Koshimizu E, Miyatake S, Tohyama J, Yamagata T, et al.
    Am J Hum Genet, 2020 04 02;106(4):549-558.
    PMID: 32169168 DOI: 10.1016/j.ajhg.2020.02.011
    De novo variants (DNVs) cause many genetic diseases. When DNVs are examined in the whole coding regions of genes in next-generation sequencing analyses, pathogenic DNVs often cluster in a specific region. One such region is the last exon and the last 50 bp of the penultimate exon, where truncating DNVs cause escape from nonsense-mediated mRNA decay [NMD(-) region]. Such variants can have dominant-negative or gain-of-function effects. Here, we first developed a resource of rates of truncating DNVs in NMD(-) regions under the null model of DNVs. Utilizing this resource, we performed enrichment analysis of truncating DNVs in NMD(-) regions in 346 developmental and epileptic encephalopathy (DEE) trios. We observed statistically significant enrichment of truncating DNVs in semaphorin 6B (SEMA6B) (p value: 2.8 × 10-8; exome-wide threshold: 2.5 × 10-6). The initial analysis of the 346 individuals and additional screening of 1,406 and 4,293 independent individuals affected by DEE and developmental disorders collectively identified four truncating DNVs in the SEMA6B NMD(-) region in five individuals who came from unrelated families (p value: 1.9 × 10-13) and consistently showed progressive myoclonic epilepsy. RNA analysis of lymphoblastoid cells established from an affected individual showed that the mutant allele escaped NMD, indicating stable production of the truncated protein. Importantly, heterozygous truncating variants in the NMD(+) region of SEMA6B are observed in general populations, and SEMA6B is most likely loss-of-function tolerant. Zebrafish expressing truncating variants in the NMD(-) region of SEMA6B orthologs displayed defective development of brain neurons and enhanced pentylenetetrazole-induced seizure behavior. In summary, we show that truncating DNVs in the final exon of SEMA6B cause progressive myoclonic epilepsy.
    Matched MeSH terms: Heterozygote
  12. Qiu B, Fang S, Ikhwanuddin M, Wong L, Ma H
    Mol Biol Rep, 2020 Apr;47(4):3011-3017.
    PMID: 32124169 DOI: 10.1007/s11033-020-05348-z
    In this study, we first conducted a genome survey assay for Sillago sihama by Illumina sequencing platform, and then developed 15 polymorphic microsatellite loci in a wild population. A total of 129.46 Gb raw data were obtained, of which 115.07 Gb were clean data, with a sequencing depth of 179.3-folds. This genome was estimated to be 522.6 Mb in size, with the heterozygosity, repeat content and GC content being 0.63%, 21% and 44%. A total of 630,028 microsatellites were identified from the genome, of which, dinucleotide repeat was the most abundant (56.80%), followed by mononucleotide repeat (30.23%). Furthermore, 60 pairs of primers were designed and synthesized based on microsatellite sequences, of which 15 were polymorphic in a wild population. A total of 91 alleles were found, with an average of 6.07 per locus. Number of alleles, observed and expected heterozygosity per locus ranged from two to 13, from 0.250 to 0.862, and from 0.396 to 0.901, respectively. Twelve loci were highly informative (PIC > 0.5), and the others were medium informative (0.25 
    Matched MeSH terms: Heterozygote
  13. Tan SC, Lim PY, Fang J, Mokhtar MFM, Hanif EAM, Jamal R
    Sci Rep, 2020 Feb 26;10(1):3508.
    PMID: 32103099 DOI: 10.1038/s41598-020-60442-3
    Numerous studies have investigated the association of MIR499A rs3746444 polymorphism with breast cancer susceptibility, but the results have been inconsistent. In this work, we performed a meta-analysis to obtain a more reliable estimate of the association between the polymorphism and susceptibility to breast cancer. A comprehensive literature search was conducted on PubMed, Scopus, Web of Science (WoS), China National Knowledge Infrastructure (CNKI), VIP and Wanfang databases up to January 2020. A total of 14 studies involving 6,797 cases and 8,534 controls were included for analysis under five genetic models: homozygous (GG vs. AA), heterozygous (AG vs. AA), dominant (AG + GG vs. AA), recessive (GG vs. AA + AG) and allele (G vs. A). A statistically significant association was observed between the polymorphism and an increased breast cancer susceptibility under all genetic models (homozygous, OR = 1.33, 95% CI = 1.03-1.71, P = 0.03; heterozygous, OR = 1.08, 95% CI = 1.00-1.16, P = 0.04; dominant, OR = 1.15, 95% CI = 1.02-1.30; P = 0.03; recessive, OR = 1.35, 95% CI = 1.06-1.72, P = 0.01; allele, OR = 1.12, 95% CI = 1.00-1.26, P = 0.04). Subgroup analysis based on ethnicity suggested that significant association was present only among Asians, but not Caucasians. In conclusion, MIR499A rs3746444 polymorphism was significantly associated with breast cancer susceptibility among Asians, suggesting its potential use as a genetic risk marker in this population.
    Matched MeSH terms: Heterozygote
  14. Delatycki MB, Alkuraya F, Archibald A, Castellani C, Cornel M, Grody WW, et al.
    Prenat Diagn, 2020 02;40(3):301-310.
    PMID: 31774570 DOI: 10.1002/pd.5611
    Reproductive carrier screening started in some countries in the 1970s for hemoglobinopathies and Tay-Sachs disease. Cystic fibrosis carrier screening became possible in the late 1980s and with technical advances, screening of an ever increasing number of genes has become possible. The goal of carrier screening is to inform people about their risk of having children with autosomal recessive and X-linked recessive disorders, to allow for informed decision making about reproductive options. The consequence may be a decrease in the birth prevalence of these conditions, which has occurred in several countries for some conditions. Different programs target different groups (high school, premarital, couples before conception, couples attending fertility clinics, and pregnant women) as does the governance structure (public health initiative and user pays). Ancestry-based offers of screening are being replaced by expanded carrier screening panels with multiple genes that is independent of ancestry. This review describes screening in Australia, Cyprus, Israel, Italy, Malaysia, the Netherlands, Saudi Arabia, the United Kingdom, and the United States. It provides an insight into the enormous variability in how reproductive carrier screening is offered across the globe. This largely relates to geographical variation in carrier frequencies of genetic conditions and local health care, financial, cultural, and religious factors.
    Matched MeSH terms: Heterozygote
  15. Patel VL, Busch EL, Friebel TM, Cronin A, Leslie G, McGuffog L, et al.
    Cancer Res, 2020 Feb 01;80(3):624-638.
    PMID: 31723001 DOI: 10.1158/0008-5472.CAN-19-1840
    Pathogenic sequence variants (PSV) in BRCA1 or BRCA2 (BRCA1/2) are associated with increased risk and severity of prostate cancer. We evaluated whether PSVs in BRCA1/2 were associated with risk of overall prostate cancer or high grade (Gleason 8+) prostate cancer using an international sample of 65 BRCA1 and 171 BRCA2 male PSV carriers with prostate cancer, and 3,388 BRCA1 and 2,880 BRCA2 male PSV carriers without prostate cancer. PSVs in the 3' region of BRCA2 (c.7914+) were significantly associated with elevated risk of prostate cancer compared with reference bin c.1001-c.7913 [HR = 1.78; 95% confidence interval (CI), 1.25-2.52; P = 0.001], as well as elevated risk of Gleason 8+ prostate cancer (HR = 3.11; 95% CI, 1.63-5.95; P = 0.001). c.756-c.1000 was also associated with elevated prostate cancer risk (HR = 2.83; 95% CI, 1.71-4.68; P = 0.00004) and elevated risk of Gleason 8+ prostate cancer (HR = 4.95; 95% CI, 2.12-11.54; P = 0.0002). No genotype-phenotype associations were detected for PSVs in BRCA1. These results demonstrate that specific BRCA2 PSVs may be associated with elevated risk of developing aggressive prostate cancer. SIGNIFICANCE: Aggressive prostate cancer risk in BRCA2 mutation carriers may vary according to the specific BRCA2 mutation inherited by the at-risk individual.
    Matched MeSH terms: Heterozygote
  16. Abdul Aziz Mohamed Yusoff, Wan Salihah Wan Abdullah, Alarmelu Nithya Ramanathan, Jafri Malin Abdullah, Zamzuri Idris
    MyJurnal
    Although the precise etiology of Glioblastoma multiforme (GBM, WHO grade IV) remains unknown, its progression
    is believed to be driven by the accumulation of multiple genetic alterations. Here, we report a case of a patient who
    developed GBM, and associated with dual alterations, particularly 4977-bp deletion in mtDNA (mtDNA4977) and
    p.Arg132His (R132H) mutation in IDH1. A 35-year old Malaysian woman patient who primary diagnosed with astrocytoma WHO grade I and subsequently after four years developed a GBM, was detected with a mtDNA4977. This
    deletion appears to be a sporadic mutation. Additionally, analysis of patient’s tumor tissue also found to harbor a heterozygous IDH1 R132H mutation. This represents the first case report of coexisting mtDNA4977 together with IDH1
    R132H mutation in a Malaysian patient of GBM. The findings of dual alterations could be of therapeutic benefit if
    these alterations were justified to be contributing to GBM growth and aggressiveness.
    Matched MeSH terms: Heterozygote
  17. Page EC, Bancroft EK, Brook MN, Assel M, Hassan Al Battat M, Thomas S, et al.
    Eur Urol, 2019 Dec;76(6):831-842.
    PMID: 31537406 DOI: 10.1016/j.eururo.2019.08.019
    BACKGROUND: Mutations in BRCA2 cause a higher risk of early-onset aggressive prostate cancer (PrCa). The IMPACT study is evaluating targeted PrCa screening using prostate-specific-antigen (PSA) in men with germline BRCA1/2 mutations.

    OBJECTIVE: To report the utility of PSA screening, PrCa incidence, positive predictive value of PSA, biopsy, and tumour characteristics after 3 yr of screening, by BRCA status.

    DESIGN, SETTING, AND PARTICIPANTS: Men aged 40-69 yr with a germline pathogenic BRCA1/2 mutation and male controls testing negative for a familial BRCA1/2 mutation were recruited. Participants underwent PSA screening for 3 yr, and if PSA > 3.0 ng/ml, men were offered prostate biopsy.

    OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: PSA levels, PrCa incidence, and tumour characteristics were evaluated. Statistical analyses included Poisson regression offset by person-year follow-up, chi-square tests for proportion t tests for means, and Kruskal-Wallis for medians.

    RESULTS AND LIMITATIONS: A total of 3027 patients (2932 unique individuals) were recruited (919 BRCA1 carriers, 709 BRCA1 noncarriers, 902 BRCA2 carriers, and 497 BRCA2 noncarriers). After 3 yr of screening, 527 men had PSA > 3.0 ng/ml, 357 biopsies were performed, and 112 PrCa cases were diagnosed (31 BRCA1 carriers, 19 BRCA1 noncarriers, 47 BRCA2 carriers, and 15 BRCA2 noncarriers). Higher compliance with biopsy was observed in BRCA2 carriers compared with noncarriers (73% vs 60%). Cancer incidence rate per 1000 person years was higher in BRCA2 carriers than in noncarriers (19.4 vs 12.0; p =  0.03); BRCA2 carriers were diagnosed at a younger age (61 vs 64 yr; p =  0.04) and were more likely to have clinically significant disease than BRCA2 noncarriers (77% vs 40%; p =  0.01). No differences in age or tumour characteristics were detected between BRCA1 carriers and BRCA1 noncarriers. The 4 kallikrein marker model discriminated better (area under the curve [AUC] = 0.73) for clinically significant cancer at biopsy than PSA alone (AUC = 0.65).

    CONCLUSIONS: After 3 yr of screening, compared with noncarriers, BRCA2 mutation carriers were associated with a higher incidence of PrCa, younger age of diagnosis, and clinically significant tumours. Therefore, systematic PSA screening is indicated for men with a BRCA2 mutation. Further follow-up is required to assess the role of screening in BRCA1 mutation carriers.

    PATIENT SUMMARY: We demonstrate that after 3 yr of prostate-specific antigen (PSA) testing, we detect more serious prostate cancers in men with BRCA2 mutations than in those without these mutations. We recommend that male BRCA2 carriers are offered systematic PSA screening.

    Matched MeSH terms: Heterozygote Detection/methods*
  18. Chew EGY, Liany H, Tan LCS, Au WL, Prakash KM, Annuar AA, et al.
    Neurobiol Aging, 2019 02;74:235.e1-235.e4.
    PMID: 30337193 DOI: 10.1016/j.neurobiolaging.2018.09.013
    Recent whole-exome sequencing studies in European patients with Parkinson's disease (PD) have identified potential risk variants across 33 novel PD candidate genes. We aim to determine if these reported candidate genes are similarly implicated in Asians by assessing common, rare, and novel nonsynonymous coding variants by sequencing all 33 genes in 198 Chinese samples and genotyping coding variants in an independent set of 9756 Chinese samples. We carried out further targeted sequencing of CD36 in an additional 576 Chinese and Korean samples. We found that only 8 of 43 reported risk variants were polymorphic in our Chinese samples. We identified several heterozygotes for rare loss-of-function mutations, including the reported CD36 p.Gln74Ter variant, in both cases and controls. We also observed 2 potential compound heterozygotes among PD cases for rare loss-of-function mutations in CD36 and SSPO. The other reported variants were common in East Asians and not associated with PD, completely absent, or only found in controls. Therefore, the 33 reported candidate genes and associated variants are unlikely to confer significant PD risk in the East Asian population.
    Matched MeSH terms: Heterozygote
  19. Lim, L. N., Yu, K. S., Chua, S. M., George, E., Lai, M. I., Wong, L., et al.
    MyJurnal
    Introduction: Filipino β°-deletion is predominant among the β-thalassaemia patients in the indigenous population of Sabah, Malaysia particularly among the Kadazandusun. Individuals who co-inherit with α- and β-thalassaemia will demonstrate milder clinical symptoms with modified complete blood count (CBC) and Hb subtype parameters. HBS1L-MYB variants act as one of the key regulator of haematopoiesis and erythropoiesis and display strong association
    with variation of HbF levels. Therefore, this study aims to evaluate the association between genetic variants in HBS1L-MYB with Hb subtypes level among Filipino β°-deletion carriers co-inherited with -α3.7 deletion. Methods: Filipino β°-deletion and -α3.7 deletion were identified using gap-polymerase chain reaction (PCR). A total of 34 subjects found with coinheritance of Filipino β°-deletion and -α3.7 deletion were subjected for HBS1L-MYB intergenic polymorphisms (HMIP) analysis. Hb subtypes level were quantified using BioRad Variant II Hb analyser. Genotyping of HBS1L-MYB variants rs9399137 and rs11759553 was done using own designed tetra primer ARMS-PCR. Results: The minor allele frequencies (MAF) of the two HMIP is found more than 0.05 (rs11759553, MAF=0.18 and rs9399137, MAF=0.15), indicating the significance of these variants among the study subjects. Significant difference was found between HbF level and HBS1L-MYB variant rs11759553 with p-value less than 0.05 (p=0.001). Subjects with homozygous genotype for rs11759553 (T/T) was found with higher HbF, followed by heterozygous (A/T) and wild type (A/A). rs11759553 and rs9399137 was found did not influence the level of HbA and HbA2. HMIP of rs11759553 and rs9399137 are found significant among Filipino β°-deletion carriers co-inherited with -α3.7deletion with its high minor allelic frequency and high HbF level. Strong association with HbF level was demonstrated when
    coinheritance of rs11759553. Conclusion: This study demonstrates that there are significant associations between certain genetic variants in HBS1L-MYB with Hb subtypes level among Filipino β°-deletion carriers co-inherited with -α3.7 deletion.
    Matched MeSH terms: Heterozygote
  20. Lye, Munn-Sann, Aishah-Farhana Shahbudin, Tey, Yin-Yee, Tor, Yin-Sim, Ling, King-Hwa, Normala Ibrahim, et al.
    Neuroscience Research Notes, 2019;2(3):20-28.
    MyJurnal
    Major depressive disorder (MDD) compromises the individual’s capacity for self-care and productivity. Single nucleotide polymorphisms (SNP) of a number of genes have been associated with MDD. The zinc transporter-3 protein, encoded by the ZnT3 (SLC30A3) gene, maintains zinc-glutamate homeostasis at the glutamatergic synapse, a disruption of which increases risk of MDD. We hypothesise that variation in SLC30A3 (rs11126936)SNP increases risk of MDD. We recruited 300 MDD cases and 300 controls, matched in theratio of 1:1 by age, gender and ethnicity. PCR-restriction fragment length polymorphism analysis was used in DNA genotyping, validated by sequencing 10%of samples. Deviation from the Hardy-Weinberg equilibrium was tested using the chi-square test. Conditional logistic regression was used to estimate adjusted odds ratios, controlling for age, gender, ethnicity, occupation and family monthly income.Genotypes G/G and G/T showed two times greater odds of developing MDD compared to variant genotype T/T (OR=1.983, 95% CI=1.031-3.815; p=0.040 and OR=2.232, 95% CI=1.100-4.533; p=0.026 respectively). Carriers of genotypes G/G and G/T of the SNP rs11126936 in SLC30A3are associated with increased risk of MDD.
    Matched MeSH terms: Heterozygote
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