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  1. Nik Lah NAZ, Taib F, Mohamad Zon E, Engku Ismail EH, Annuar AA
    Cureus, 2023 Feb;15(2):e34562.
    PMID: 36743908 DOI: 10.7759/cureus.34562
    Pericentric inversion of chromosome 9 (inv(9)) is one of the most common variants seen in a normal human karyotype that occurs during meiosis. Despite being categorized as a normal variant, some studies using classical cytogenetics have recently shown that inv(9) could be associated with azoospermia, congenital anomalies, growth retardation, and rarely with abnormal karyotype. However, there is no reported association with cyclopia. Interestingly this genetic variant involves twin fetuses. A 36-year-old multiparous lady with dichorionic diamniotic twin pregnancy presented to the fetomaternal unit with fetal growth restriction at 34 weeks of gestation. An ultrasound scan revealed both have microcephaly, fisting hands, holoprosencephaly, and proboscis suspicious of Patau syndrome. Amniocentesis was not issued due to late pregnancy and guarded prognosis. The mother presented with pre-eclampsia at 35 weeks of gestation. The pregnancy managed to prolong up to 36 weeks after which caesarean section was performed due to the leading twin being in a transverse lie. Two baby twin girls were born 3 minutes apart with microcephaly and cyclops appearance. Chromosomal analysis of both twins revealed similar karyotypes of 46, XX, inv(9)(p11,q13). Pericentric inversion of chromosome 9 is regarded as a normal chromosomal variation in the general population, but in twins with cyclops is considered rare. Early referral to a tertiary hospital for twin management is highly required. It may identify fetuses with such abnormalities and counsel the parents with appropriate management.
  2. Ankathil R, Zakaria WNA, Hamid MR, Ismail SM, Mohd Yunus N, Annuar AA, et al.
    Cureus, 2024 Sep;16(9):e68402.
    PMID: 39360045 DOI: 10.7759/cureus.68402
    Chromosomal rearrangement can disrupt gene function by interfering with coding sequences or their regulatory regions. The breakpoint in these rearrangements can pinpoint the disease-related gene's location. This paper presents two rare cases of chromosomal rearrangement involving chromosome 6 (6p24-25) and chromosome 14 (14q22-23). The first case involves a girl with hearing impairment, inheriting a balanced translocation of chromosomes 6 and 14 from her father. The second case describes a dysmorphic baby boy with congenital bilateral choanal atresia and a tertiary trisomy, involving a translocation between chromosome 6 (6p24) and chromosome 14 (14q22), resulting in a derivative chromosome (14) in addition to the normal complement of chromosomes 6 and 14. The boy's mother had a history of four recurrent miscarriages. However, the origin of this tertiary trisomy in the second case presented could not be delineated because the parents did not consent and declined their blood samples for karyotyping. Parental karyotyping and chromosomal analysis are crucial for investigating recurrent miscarriages, identifying genetic causes, guiding reproductive decisions, and improving successful pregnancy outcomes for affected couples.
  3. Annuar AA, Ankathil R, Mohd Yunus N, Husin A, Ab Rajab NS, Abdul Aziz AA, et al.
    Asian Pac J Cancer Prev, 2021 Feb 01;22(2):565-571.
    PMID: 33639675 DOI: 10.31557/APJCP.2021.22.2.565
    BACKGROUND: The FAS mediated apoptosis pathway involving the FAS and FASL genes plays a crucial role in the regulation of apoptotic cell death and imatinib mesylate (IM) mechanism of action. Promoter polymorphisms FAS-670 A>G and FAS-844 T>C which alter the transcriptional activity of these genes may grant a risk to develop cancer and revamp the drug activities towards the cancer cell. We investigated the association of these two polymorphisms with the susceptibility risk and IM treatment response in Malaysian chronic myeloid leukaemia (CML) patients.

    METHODS: This is a retrospective study, which included 93 CML patients and 98 controls. The polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method was used to genotype the FAS and FASL polymorphisms. Data nanlysis was done using SPSS Version 22. The associations of the genotypes with susceptibility risk and IM response in CML patients were assessed by means of logistic regression analysis and deriving odds ratio with 95% CI.

    RESULTS: We observed a significant association between FASL-844T>C polymorphism and CML susceptibility risk and IM response. Variant C allele and FASL-844 CC variant genotype carriers had significantly higher risk for CML susceptibility (OR 1.756, CI 1.163-2.652, p=0.007 and OR 2.261, CI 1.013-5.047, p=0.047 respectively). Conversely, the heterozygous genotype FASL-844 TC conferred lower risk for CML susceptibility (OR 0.379, CI 0.176-0.816, p=0.013). The heterozygous and homozygous variant genotypes and variant C alleles were found to confer a lower risk for the development of IM resistance with OR 0.129 (95% CI: 0.034-0.489 p=0.003), OR 0.257 (95% CI: 0.081-0.818, p=0.021), and OR 0.486 (95% CI: 0.262-0.899, p=0.021) respectively. We also found that FAS-670 A>G polymorphism was not associated with CML susceptibility risk or IM response.

    CONCLUSION: The genetic polymorphism FASL-844 T>C may contribute to the CML susceptibility risk and also IM treatment response in CML patients. Accodringly, it may be useful as a biomarker for predicting CML susceptibility risk and IM resistance.

  4. 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.
  5. Lim SY, Tan AH, Foo JN, Tan YJ, Chew EG, Annuar AA, et al.
    J Mov Disord, 2024 Apr;17(2):213-217.
    PMID: 38291878 DOI: 10.14802/jmd.24009
    Lysosomal dysfunction plays an important role in neurodegenerative diseases, including Parkinson's disease (PD) and possibly Parkinson-plus syndromes such as progressive supranuclear palsy (PSP). This role is exemplified by the involvement of variants in the GBA1 gene, which results in a deficiency of the lysosomal enzyme glucocerebrosidase and is the most frequently identified genetic factor underlying PD worldwide. Pathogenic variants in the SMPD1 gene are a recessive cause of Niemann-Pick disease types A and B. Here, we provide the first report on an association between a loss-of-function variant in the SMPD1 gene present in a heterozygous state (p.Pro332Arg/p.P332R, which is known to result in reduced lysosomal acid sphingomyelinase activity), with PSP-Richardson syndrome in three unrelated patients of Chinese ancestry.
  6. Junker J, Lange LM, Vollstedt EJ, Roopnarain K, Doquenia MLM, Annuar AA, et al.
    medRxiv, 2024 Apr 09.
    PMID: 38529492 DOI: 10.1101/2024.03.12.24304154
    Until recently, about three-quarters of all monogenic Parkinson's disease (PD) studies were performed in European/White ancestry, thereby severely limiting our insights into genotype-phenotype relationships at global scale. The first systematic approach to embrace monogenic PD worldwide, The Michael J. Fox Foundation Global Monogenic PD (MJFF GMPD) Project, contacted authors of publications reporting individuals carrying pathogenic variants in known PD-causing genes. In contrast, the Global Parkinson's Genetics Program's (GP2) Monogenic Network took a different approach by targeting PD centers not yet represented in the medical literature. Here, we describe combining both efforts in a "merger project" resulting in a global monogenic PD cohort with build-up of a sustainable infrastructure to identify the multi-ancestry spectrum of monogenic PD and enable studies of factors modifying penetrance and expression of monogenic PD. This effort demonstrates the value of future research based on team science approaches to generate comprehensive and globally relevant results.
  7. Halim-Fikri H, Etemad A, Abdul Latif AZ, Merican AF, Baig AA, Annuar AA, et al.
    BMC Res Notes, 2015;8:176.
    PMID: 25925844 DOI: 10.1186/s13104-015-1123-y
    The Malaysian Node of the Human Variome Project (MyHVP) is one of the eighteen official Human Variome Project (HVP) country-specific nodes. Since its inception in 9(th) October 2010, MyHVP has attracted the significant number of Malaysian clinicians and researchers to participate and contribute their data to this project. MyHVP also act as the center of coordination for genotypic and phenotypic variation studies of the Malaysian population. A specialized database was developed to store and manage the data based on genetic variations which also associated with health and disease of Malaysian ethnic groups. This ethnic-specific database is called the Malaysian Node of the Human Variome Project database (MyHVPDb).
  8. Junker J, Lange LM, Vollstedt EJ, Roopnarain K, Doquenia MLM, Annuar AA, et al.
    Mov Disord, 2024 Jul 30.
    PMID: 39076159 DOI: 10.1002/mds.29925
    BACKGROUND: Until recently, about three-quarters of all monogenic Parkinson's disease (PD) studies were performed in European/White ancestry, thereby severely limiting our insights into genotype-phenotype relationships at a global scale.

    OBJECTIVE: To identify the multi-ancestry spectrum of monogenic PD.

    METHODS: The first systematic approach to embrace monogenic PD worldwide, The Michael J. Fox Foundation Global Monogenic PD Project, contacted authors of publications reporting individuals carrying pathogenic variants in known PD-causing genes. In contrast, the Global Parkinson's Genetics Program's Monogenic Network took a different approach by targeting PD centers underrepresented or not yet represented in the medical literature.

    RESULTS: In this article, we describe combining both efforts in a merger project resulting in a global monogenic PD cohort with the buildup of a sustainable infrastructure to identify the multi-ancestry spectrum of monogenic PD and enable studies of factors modifying penetrance and expressivity of monogenic PD.

    CONCLUSIONS: This effort demonstrates the value of future research based on team science approaches to generate comprehensive and globally relevant results. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

  9. Foo JN, Chew EGY, Chung SJ, Peng R, Blauwendraat C, Nalls MA, et al.
    JAMA Neurol, 2020 06 01;77(6):746-754.
    PMID: 32310270 DOI: 10.1001/jamaneurol.2020.0428
    Importance: Large-scale genome-wide association studies in the European population have identified 90 risk variants associated with Parkinson disease (PD); however, there are limited studies in the largest population worldwide (ie, Asian).

    Objectives: To identify novel genome-wide significant loci for PD in Asian individuals and to compare genetic risk between Asian and European cohorts.

    Design Setting, and Participants: Genome-wide association data generated from PD cases and controls in an Asian population (ie, Singapore/Malaysia, Hong Kong, Taiwan, mainland China, and South Korea) were collected from January 1, 2016, to December 31, 2018, as part of an ongoing study. Results were combined with inverse variance meta-analysis, and replication of top loci in European and Japanese samples was performed. Discovery samples of 31 575 individuals passing quality control of 35 994 recruited were used, with a greater than 90% participation rate. A replication cohort of 1 926 361 European-ancestry and 3509 Japanese samples was analyzed. Parkinson disease was diagnosed using UK Parkinson's Disease Society Brain Bank Criteria.

    Main Outcomes and Measures: Genotypes of common variants, association with disease status, and polygenic risk scores.

    Results: Of 31 575 samples identified, 6724 PD cases (mean [SD] age, 64.3 [10] years; age at onset, 58.8 [10.6] years; 3472 [53.2%] men) and 24 851 controls (age, 59.4 [11.4] years; 11 030 [45.0%] men) were analyzed in the discovery study. Eleven genome-wide significant loci were identified; 2 of these loci were novel (SV2C and WBSCR17) and 9 were previously found in Europeans. Replication in European-ancestry and Japanese samples showed robust association for SV2C (rs246814; odds ratio, 1.16; 95% CI, 1.11-1.21; P = 1.17 × 10-10 in meta-analysis of discovery and replication samples) but showed potential genetic heterogeneity at WBSCR17 (rs9638616; I2=67.1%; P = 3.40 × 10-3 for hetereogeneity). Polygenic risk score models including variants at these 11 loci were associated with a significant improvement in area under the curve over the model based on 78 European loci alone (63.1% vs 60.2%; P = 6.81 × 10-12).

    Conclusions and Relevance: This study identified 2 apparently novel gene loci and found 9 previously identified European loci to be associated with PD in this large, meta-genome-wide association study in a worldwide population of Asian individuals and reports similarities and differences in genetic risk factors between Asian and European individuals in the risk for PD. These findings may lead to improved stratification of Asian patients and controls based on polygenic risk scores. Our findings have potential academic and clinical importance for risk stratification and precision medicine in Asia.

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