Displaying publications 1 - 20 of 135 in total

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  1. Tan KL, Tan JA, Wong YC, Wee YC, Thong MK, Yap SF
    Genet. Test., 2001;5(1):17-22.
    PMID: 11336396 DOI: 10.1089/109065701750168626
    Beta-thalassemia major patients have chronic anemia and are dependent on blood transfusions to sustain life. Molecular characterization and prenatal diagnosis of beta3-thalassemia is essential in Malaysia because about 4.5% of the population are heterozygous carriers for beta-thalassemia. The high percentage of compound heterozygosity (47.62%) found in beta-thalassemia major patients in the Thalassaemia Registry, University of Malaya Medical Centre (UMMC), Malaysia, also supports a need for rapid, economical, and sensitive protocols for the detection of beta-thalassemia mutations. Molecular characterization of beta-thalassemia mutations in Malaysia is currently carried out using ARMS, which detects a single beta-thalassemia mutation per PCR reaction. We developed and evaluated Combine amplification refractory mutation system (C-ARMS) techniques for efficient molecular detection of two to three beta-thalassemia mutations in a single PCR reaction. Three C-ARMS protocols were evaluated and established for molecular characterization of common beta-thalassemia mutations in the Malay and Chinese ethnic groups in Malaysia. Two C-ARMS protocols (cd 41-42/IVSII #654 and -29/cd 71-72) detected the beta-thalassemia mutations in 74.98% of the Chinese patients studied. The CARMS for cd 41-42/IVSII #654 detected beta-thalassemia mutations in 72% of the Chinese families. C-ARMS for cd 41-42/IVSI #5/cd 17 allowed detection of beta-thalassemia mutations in 36.53% of beta-thalassemia in the Malay patients. C-ARMS for cd 41-42/IVSI #5/cd 17 detected beta-thalassemia in 45.54% of the Chinese patients. We conclude that C-ARMS with the ability to detect two to three mutations in a single reaction provides more rapid and cost-effective protocols for beta-thalassemia prenatal diagnosis and molecular analysis programs in Malaysia.
    Matched MeSH terms: DNA Mutational Analysis/economics*; DNA Mutational Analysis/methods*
  2. George E, Huisman TH, Yang KG, Kutlari F, Wilson JB, Kutlar A, et al.
    Med J Malaysia, 1989 Sep;44(3):259-62.
    PMID: 2626142
    A new haemoglobin, Haemoglobin Malay is described in a 22 year old Malay. Structural analysis showed a AAC----AGC mutation in codon 17, with the production of an abnormal beta chain (beta Malay) that has an Asn----Ser substitution at position beta 19. This haemoglobin variant could not be detected by conventional procedures.
    Matched MeSH terms: DNA Mutational Analysis
  3. Looi ML, Sivalingam M, Husin ND, Radin FZ, Isa RM, Zakaria SZ, et al.
    Clin. Chim. Acta, 2011 May 12;412(11-12):999-1002.
    PMID: 21315703 DOI: 10.1016/j.cca.2011.02.006
    BACKGROUND: Beta thalassemia represents a great heterogeneity as over 300 mutations have been identified and each population at-risk has its own spectrum of mutations. Molecular characterization with high accuracy, sensitivity and economics is required for population screening and genetic counseling.
    METHODS: We used the MALDI-TOF mass spectrometry (MS) platform to develop novel multiplex assays for comprehensive detection of 27 mutations in beta-thalassemia patients. Six multiplex assays were designed to detect 13 common known ß-mutations, namely CD41/42, CD71/72, IVS1-5, IVS1-1, CD26, IVS2-654, CAP+1, CD19, -28, -29, IVS1-2, InCD (T-G) and CD17; and 14 rare ß-mutations, i.e. InCD (A-C), CD8/9, CD43, -86, CD15, Poly A, Poly T/C, IVS2-1, CD1, CD35/36, CD27/28, CD16, CD37, and 619bpDEL in 165 samples. We compared the efficiencies of genotyping by MS and Amplification Refractory Mutation System (ARMS). Discrepant results were confirmed by sequencing analysis.
    RESULTS: A total of 88.7% (260/293 allele) of MS and ARMS results was in agreement. More than fifty percent of the discrepant result was due to the false interpretation of ARMS results. Failed CD19 assay by MS method might be due to the assay design. The MS method detected 5 rare ß-mutations (CD15, CD35/36, CD8/9, Poly A and Poly T/C) presented in 13 alleles, which were not included in the ARMS screening panel.
    CONCLUSION: We revealed that the MS method is a sensitive, high-throughput, highly automated, flexible, and cost-effective alternative to conventional ß-thalassemia genotyping methods.
    Matched MeSH terms: DNA Mutational Analysis/methods*
  4. Harano K, Harano T
    Rinsho Byori, 2010 Apr;58(4):325-31.
    PMID: 20496759
    Hb and gene analyses of a Malaysian mother and her two daughters with microcytic anemia living in Japan were performed. Hb analyses of their hemolysates by IEF and DEAE-HPLC revealed high values of Hb A2 and HbF, but abnormal Hbs such as Hb E and Hb Constant Spring, which cause beta- and alpha-thalassemia traits, were not detected. From these data, they were suspected to be beta-thalassemia carriers. The thalassemic mutations commonly found in the Asian area by ARMS and nucleotide sequencing methods were not detected, and the frameworks of the beta-globin gene and the haplotypes of the beta-like globin gene cluster between the mother and daughters were not identical. These results led us to conclude that there was a beta(0)-thalassemia mutation with a large deletion from the beta-globin gene beyond the 3'beta/BamHI polymorphic site 3' downstream to the beta-globin gene. However, the range of the deletion from the beta-like globin gene cluster has not yet been completed in detail. Recently, there have been many foreigners mainly from Asian countries in Japan. We may encounter people with the rare type thalassemic mutation described in the text besides the mutations frequently found in Asian countries.
    Matched MeSH terms: DNA Mutational Analysis/methods
  5. Abdullah WA, Jamaluddin NB, Kham SK, Tan JA
    PMID: 9031421
    The spectrum of beta-thalassemia mutations in Malays in Singapore and Kelantan (Northeast Malaysia) was studied. Allele specific priming was used to determine the mutations in beta-carriers at -28, Codon 17, IVSI #1, IVSI #5, Codon 41-42 and IVSII #654 along the beta-globin gene. The most common structural hemoglobin variant in Southeast Asia, Hb E, was detected by DNA amplification with restriction enzyme (Mnl1) analysis. Direct genomic sequencing was carried out to detect the beta-mutations uncharacterized by allele-specific priming. The most prevalent beta-mutations in Singaporean Malays were IVSI #5 (45.83%) followed by Hb E (20.83%), codon 15 (12.5%) and IVSI #1 and IVSII #654 at 4.17% each. In contrast, the distribution of the beta-mutations in Kelantan Malays differed, with Hb E as the most common mutation (39.29%) followed by IVSI #5 (17.86%), codon 41-42 (14.29%), codon 19 (10.71%) and codon 17 (3.57%). The beta-mutations in Kelantan Malays follow closely the distribution of beta-mutations in Thais and Malays of Southern Thailand and Malays of West Malaysia. The AAC-->AGC base substitution in codon 19 has been detected only in these populations. The spectrum of beta-mutations in the Singaporean Malays is more similar to those reported in Indonesia with the beta-mutation at codon 15 (TGG-->TAG) present in both populations. The characterization of beta-mutations in Singaporean and Kelantan Malays will facilitate the establishment of effective prenatal diagnosis programs for beta-thalassemia major in this ethnic group.
    Matched MeSH terms: DNA Mutational Analysis*
  6. Lama R, Yusof W, Shrestha TR, Hanafi S, Bhattarai M, Hassan R, et al.
    Hematol Oncol Stem Cell Ther, 2022 Mar 01;15(1):14-20.
    PMID: 33592169 DOI: 10.1016/j.hemonc.2021.01.004
    BACKGROUND: Beta-thalassemia is a genetic disorder that is inherited in an autosomal recessive pattern. This genetic disease leads to a defective beta-globin hemoglobin chain causing partial or complete beta-globin chain synthesis loss. Beta-thalassemia major patients need a continuous blood transfusion and iron chelation to maintain the normal homeostasis of red blood cells (RBCs) and other systems in the body. Patients also require treatment procedures that are costly and tedious, resulting in a serious health burden for developing nations such as Nepal.

    METHODS: A total of 61 individuals clinically diagnosed to have thalassemia were genotyped with multiplex amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Twenty-one major mutations were investigated using allele-specific primers grouped into six different panels.

    RESULTS: The most common mutations found (23%) were IVS 1-5 (G-C) and Cd 26 (G-A) (HbE), followed by 619 deletion, Cd 8/9 (+G), Cd 16 (-C), Cd 41/42 (-TTCT), IVS 1-1 (G-T), Cd 19 (A-G), and Cd 17 (A-T) at 20%, 12%, 8%, 6%, 4%, 3%, and 1%, respectively.

    CONCLUSION: The results of this study revealed that Nepal's mutational profile is comparable to that of its neighboring countries, such as India and Myanmar. This study also showed that thalassemia could be detected across 17 Nepal's ethnic groups, especially those whose ancestors originated from India and Central Asia.

    Matched MeSH terms: DNA Mutational Analysis/methods
  7. Nasuha NA, Daud AH, Ghazali MM, Yusoff AA, Zainuddin N, Abdullah JM, et al.
    Asian J Surg, 2003 Apr;26(2):120-5.
    PMID: 12732498
    A case of pleomorphic xanthoastrocytoma in a 10-year-old Malay boy is reported. The patient presented with headache and epilepsy. On computed tomography, a ring-enhancing low-density lesion was observed in the left fronto-temporal area. During surgery, a cystic tumour containing serous fluid was found and almost totally removed. Histologically, the tumour exhibited marked pleomorphism of oval and spindle-shaped cells intermixed with uni- and multinucleated giant cells, and xanthomatous cells with foamy cytoplasm. The tumour displayed pericellular reticulin and periodic acid-Schiff positive granules. Focally, six mitotic characters per 10 high-power fields were seen, and necrosis was confined only to the inner lining of the cyst. Mutational analysis showed that a frameshift mutation (a 4-bp deletion) in the p53 gene had occurred in codons 273 and 274 of exon 8. No mutation was detected in the p16 gene. No allelic loss and/or loss of heterozygosity were observed on chromosome 10 using microsatellite marker D105532. The patient was treated with postoperative radiotherapy because of histological anaplasia and the presence of residual tumour. The patient showed marked neurological recovery after a follow-up period of 2 years.
    Matched MeSH terms: DNA Mutational Analysis
  8. Mohamed Yusoff AA, Zulfakhar FN, Sul’ain MD, Idris Z, Abdullah JM
    Asian Pac J Cancer Prev, 2016 12 01;17(12):5195-5201.
    PMID: 28125199
    Background: Brain tumors, constituting one of the most deadly forms of cancer worldwide, result from the accumulation of multiple genetic and epigenetic alterations in genes and signaling pathways. Isocitrate dehydrogenase enzyme isoform 1 (IDH1) mutations are frequently identified in primary brain tumors and acute myeloid leukemia. Studies on IDH1 gene mutations have been extensively performed in various populations worldwide but not in Malaysia. This work was conducted to study the prevalence of IDH1 c.395G>A (R132H) hotspot mutations in a group of Malaysian patients with brain tumors in order to gain local data for the IDH1 mutation profile in our population. Methods: Mutation analysis of c.395G>A (R132H) of IDH1 was performed in 40 brain tumor specimens by the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) and then verified by direct sequencing. Associations between the IDH1 c.395G>A (R132H) mutation and clinicopathologic characteristics were also analyzed. Results: The IDH1 c.395G>A (R132H) mutation was detected in 14/40 patients (35%). A significant association was found with histological tumor types, but not with age, gender and race. Conclusions: IDH1 is frequently mutated and associated with histological subtypes in Malay brain tumors.
    Matched MeSH terms: DNA Mutational Analysis
  9. Mohd Yusoff, N., Choo, K.E., Ghazali, S., Ibrahim, I., Mohd Hussin, Z.A., Mohd Yunus, et al.
    MyJurnal
    Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked red blood cell enzymopathy common in malaria endemic areas. Individuals affected by this disease show a wide variety of clinical signs including neonatal jaundice. In this preliminary report we describe the heterogeneity of G6PD deficient gene in neonatal jaundice in the Malay population in Kelantan. Thirteen G6PD deficient Malay neonates with hyperbilirubinemia were subjected to mutation analysis of the G6PD gene for known candidate mutations. Molecular defects were identified in the 13 patients studied. Though all of these were mis-sense mutations, identified nucleotide changes were heterogeneous. Six patients were found to have a C to T nucleotide change at nucleotide 563 of the G6PD gene (C563T), corresponding to G6PD Mediterranean; three cases had a single nucleotide change at T383C (G6PD Vanua Lava), two cases had G487A (G6PD Mahidol) and two cases had G1376T (G6PD Canton). These findings suggest that there are heterogeneous mutations of the G6PD gene associated with neonatal jaundice in the Malay population in Kelantan.
    Matched MeSH terms: DNA Mutational Analysis
  10. Tan LP, Ng BK, Balraj P, Poh BH, Lim PK, Peh SC
    Hum Genet, 2005 Dec;118(3-4):539-40.
    PMID: 16521263
    Matched MeSH terms: DNA Mutational Analysis
  11. Mohamed Yusoff AA, Mohd Nasir KN, Haris K, Mohd Khair SZN, Abdul Ghani ARI, Idris Z, et al.
    Oncol Lett, 2017 Nov;14(5):5179-5188.
    PMID: 29098023 DOI: 10.3892/ol.2017.6851
    Although the role of nuclear-encoded gene alterations has been well documented in brain tumor development, the involvement of the mitochondrial genome in brain tumorigenesis has not yet been fully elucidated and remains controversial. The present study aimed to identify mutations in the mitochondrial DNA (mtDNA) control region D-loop in patients with brain tumors in Malaysia. A mutation analysis was performed in which DNA was extracted from paired tumor tissue and blood samples obtained from 49 patients with brain tumors. The D-loop region DNA was amplified using the PCR technique, and genetic data from DNA sequencing analyses were compared with the published revised Cambridge sequence to identify somatic mutations. Among the 49 brain tumor tissue samples evaluated, 25 cases (51%) had somatic mutations of the mtDNA D-loop, with a total of 48 mutations. Novel mutations that had not previously been identified in the D-loop region (176 A-deletion, 476 C>A, 566 C>A and 16405 A-deletion) were also classified. No significant associations between the D-loop mutation status and the clinicopathological parameters were observed. To the best of our knowledge, the current study presents the first evidence of alterations in the mtDNA D-loop regions in the brain tumors of Malaysian patients. These results may provide an overview and data regarding the incidence of mitochondrial genome alterations in Malaysian patients with brain tumors. In addition to nuclear genome aberrations, these specific mitochondrial genome alterations may also be considered as potential cancer biomarkers for the diagnosis and staging of brain cancers.
    Matched MeSH terms: DNA Mutational Analysis
  12. Ngoi ST, Thong KL
    Biomed Res Int, 2014;2014:718084.
    PMID: 25371903 DOI: 10.1155/2014/718084
    The increased Salmonella resistance to quinolones and fluoroquinolones is a public health concern in the Southeast Asian region. The objective of this study is to develop a high resolution melt curve (HRM) assay to rapidly screen for mutations in quinolone-resistant determining region (QRDR) of gyrase and topoisomerase IV genes. DNA sequencing was performed on 62 Salmonella strains to identify mutations in the QRDR of gyrA, gyrB, parC, and parE genes. Mutations were detected in QRDR of gyrA (n = 52; S83F, S83Y, S83I, D87G, D87Y, and D87N) and parE (n = 1; M438I). Salmonella strains with mutations within QRDR of gyrA are generally more resistant to nalidixic acid (MIC 16 > 256 μg/mL). Mutations were uncommon within the QRDR of gyrB, parC, and parE genes. In the HRM assay, mutants can be distinguished from the wild-type strains based on the transition of melt curves, which is more prominent when the profiles are displayed in difference plot. In conclusion, HRM analysis allows for rapid screening for mutations at the QRDRs of gyrase and topoisomerase IV genes in Salmonella. This assay markedly reduced the sequencing effort involved in mutational studies of quinolone-resistance genes.
    Matched MeSH terms: DNA Mutational Analysis/methods*
  13. Azize NA, Ngah WZ, Othman Z, Md Desa N, Chin CB, Md Yunus Z, et al.
    J Hum Genet, 2014 Nov;59(11):593-7.
    PMID: 25231368 DOI: 10.1038/jhg.2014.69
    Glycine encephalopathy (GCE) or nonketotic hyperglycinemia is an inborn error of glycine metabolism, inherited in an autosomal recessive manner due to a defect in any one of the four enzymes aminomethyltransferase (AMT), glycine decarboxylase (GLDC), glycine cleavage system protein-H (GCSH) and dehydrolipoamide dehydrogenase in the glycine cleavage system. This defect leads to glycine accumulation in body tissues, including the brain, and causes various neurological symptoms such as encephalopathy, hypotonia, apnea, intractable seizures and possible death. We screened 14 patients from 13 families with clinical and biochemical features suggestive of GCE for mutation in AMT, GLDC and GCSH genes by direct sequencing and genomic rearrangement of GLDC gene using a multiplex ligation-dependant probe amplification. We identified mutations in all 14 patients. Seven patients (50%) have biallelic mutations in GLDC gene, six patients (43%) have biallelic mutations in AMT gene and one patient (7%) has mutation identified in only one allele in GLDC gene. Majority of the mutations in GLDC and AMT were missense mutations and family specific. Interestingly, two mutations p.Arg265His in AMT gene and p.His651Arg in GLDC gene occurred in the Penan sub-population. No mutation was found in GCSH gene. We concluded that mutations in both GLDC and AMT genes are the main cause of GCE in Malaysian population.
    Matched MeSH terms: DNA Mutational Analysis/methods
  14. Chiu YH, Chang YC, Chang YH, Niu DM, Yang YL, Ye J, et al.
    J Hum Genet, 2012 Feb;57(2):145-52.
    PMID: 22237589 DOI: 10.1038/jhg.2011.146
    The enzyme 6-pyruvoyl-tetrahydropterin synthase (PTPS, gene symbol: PTS) is involved in the second step of the de novo biosynthesis of tetrahydrobiopterin (BH4), which is a vital cofactor of nitric oxide synthases and three types of aromatic amino acid hydroxylases; the latter are important enzymes in the production of neurotransmitters. We conducted a study of PTS mutations in East Asia, including Taiwan, Mainland China, Japan, South Korea, the Philippines, Thailand and Malaysia. A total of 43 mutations were identified, comprising 22 previously reported mutations and 21 new discovered mutations. Among these, the c.155A>G, c.259C>T, c. 272A>G, c.286G>A and c.84-291A>G mutations were the most common PTS mutations in East Asia, while the c.58T>C and c.243G>A mutations were, respectively, specific to Filipinos and Japanese originating from Okinawa. Further studies demonstrated that each of the mutations listed above was in linkage disequilibrium to a specific allele of polymorphic microsatellite marker, D11S1347. These results suggest the presence of founder effects that have affected these frequent mutations in East Asia populations. In this context, D11S1347 should become one of the most reliable polymorphic markers for use in prenatal diagnosis among PTPS deficient families, especially where mutations are yet to be identified.
    Matched MeSH terms: DNA Mutational Analysis*
  15. Tan JA, Kok JL, Tan KL, Wee YC, George E
    Genes Genet. Syst., 2009 Feb;84(1):67-71.
    PMID: 19420802
    Co-inheritance of alpha-thalassemia with homozygosity or compound heterozygosity for beta-thalassemia may ameliorate beta-thalassemia major. A wide range of clinical phenotypes is produced depending on the number of alpha-thalassemia alleles (-alpha/alphaalpha --/alphaalpha, --/-alpha). The co-inheritance of beta-thalassemia with alpha-thalassemia with a single gene deletion (-alpha/alphaalpha) is usually associated with thalassemia major. In contrast, the co-inheritance of beta-thalassemia with two alpha-genes deleted in cis or trans (--/alphaalpha or -alpha/-alpha) generally produces beta-thalassemia intermedia. In Southeast Asia, the most common defect responsible for alpha-thalassemia is the Southeast Asian (SEA) deletion of 20.5 kilobases. The presence of the SEA deletion with Hb Constant Spring (HbCS) produces HbH-CS disease. Co-inheritance of HbH-CS with compound heterozygosity for beta-thalassemia is very rare. This study presents a Malay patient with HbH-CS disorder and beta degrees/beta+-thalassemia. The SEA deletion was confirmed in the patient using a duplex-PCR. A Combine-Amplification Refractory Mutation System (C-ARMS) technique to simultaneously detect HbCS and Hb Quong Sze confirmed HbCS in the patient. Compound heterozygosity for CD41/42 and Poly A was confirmed using the ARMS. This is a unique case as the SEA alpha-gene deletion in cis (--SEA/alphaalpha) is generally not present in the Malays, who more commonly possess the two alpha-gene deletion in trans (-alpha/-alpha). In addition, the beta-globin gene mutation at CD41/42 is a common mutation in the Chinese and not in the Malays. The presence of both the SEA deletion and CD41/42 in the mother of the patient suggests the possible introduction of these two defects into the family by marriage with a Chinese.
    Matched MeSH terms: DNA Mutational Analysis/methods
  16. Aishah ZS, Khairi MD, Normastura AR, Zafarina Z, Zilfalil BA
    J Laryngol Otol, 2008 Dec;122(12):1284-8.
    PMID: 18353197 DOI: 10.1017/S0022215108002041
    To determine the frequency and type of gap junction protein beta-2 gene mutations in Malay patients with autosomal recessive, non-syndromic hearing loss.
    Matched MeSH terms: DNA Mutational Analysis/methods
  17. Abdullah JM, Ahmad F, Ahmad KA, Ghazali MM, Jaafar H, Ideris A, et al.
    Neurol Res, 2007 Apr;29(3):239-42.
    PMID: 17509221
    Brain tumorigenesis is a complex process involving multiple genetic alterations. Cyclin D1 and BAX genes are two of the most important regulators in controlling the normal proliferation and apoptosis of cells, respectively. In this study, we analysed the possibilities of involvement of cyclin D1 and BAX genes in the gliomagenesis.
    Matched MeSH terms: DNA Mutational Analysis/methods
  18. Lee AS, Ho GH, Oh PC, Balram C, Ooi LL, Lim DT, et al.
    Hum Mutat, 2003 Aug;22(2):178.
    PMID: 12872263
    The mutation spectrum of the BRCA1 gene among ethnic groups from Asia has not been well studied. We investigated the frequency of mutations in the BRCA1 gene among Malay breast cancer patients from Singapore, independent of family history. By using the protein truncation test (PTT) and direct sequencing, BRCA1 mutations were detected in 6 of 49 (12.2%) unrelated patients. Four novel missense mutations in exon 11, T557A (1788A>G), T582A (1863A>G), N656S (2086A>G) and P684S (2169C>T) were identified in one patient. Two patients had missense mutations in exon 23, V1809A (5545T>C), which has been previously detected in individuals from Central and Eastern Europe. Three unrelated patients had the deleterious 2846insA frameshift mutation in exon 11. Methylation specific PCR (MSP) of the promoter region of the BRCA1 gene detected hypermethylation of tumor DNA in an additional 2 patients. Haplotype analysis using the microsatellite markers D17S855, D17S1323 and D17S1325 revealed a common haplotype for the three unrelated patients and their three relatives with the 2846insA mutation. These findings strongly suggest that the 2846insA mutation, the most common deleterious mutation in this study, may possibly be a founder mutation in breast cancer patients of Malay ethnic background.
    Matched MeSH terms: DNA Mutational Analysis/methods
  19. Ismail NF, Rani AQ, Nik Abdul Malik NM, Boon Hock C, Mohd Azlan SN, Abdul Razak S, et al.
    J Mol Diagn, 2017 03;19(2):265-276.
    PMID: 28087349 DOI: 10.1016/j.jmoldx.2016.10.009
    Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous disorder characterized by tumor growth in multiple organs and caused by mutations in either TSC1 or TSC2 genes. Because of their relatively large genomic sizes, absence of hotspots, and common type of mutations, mutation detection in TSC1 and TSC2 genes has been challenging. We devised a combination of multiple ligation-dependent probe amplification (MLPA) and amplicon sequencing (AS) to simplify the detection strategy, yet we come up with reasonably high detection rate. Thirty-four Malaysian patients diagnosed with TSC were referred to Human Genome Center, Universiti Sains Malaysia. We used a combination of MLPA to detect large copy number changes and AS to detect smaller mutations. TSC1 pathogenic or likely pathogenic mutations were found in 6 patients (18%) and TSC2 in 21 patients (62%), whereas 6 patients (18%) show no mutations and 1 patient (2%) showed only TSC2 missense variant with uncertain significance. Six of the mutations are novel. Our detection strategy costs 81% less and require 1 working week less than the conventional strategy. Confirmatory sequencing using Sanger method on a few representative mutations showed agreement with results of the AS. Combination of MLPA and Illumina MiSeq AS provides a simplified strategy and reasonably high detection rate for TSC1/TSC2 mutation, which suggested application of the strategies into clinical molecular diagnostics.
    Matched MeSH terms: DNA Mutational Analysis/methods
  20. Rethanavelu K, Fung JLF, Chau JFT, Pei SLC, Chung CCY, Mak CCY, et al.
    Am J Med Genet A, 2020 02;182(2):279-288.
    PMID: 31755649 DOI: 10.1002/ajmg.a.61412
    Alström syndrome (AS) is a monogenic syndromic ciliopathy caused by mutations in the ALMS1 (Alström Syndrome 1) gene. A total of 21 subjects with AS from 20 unrelated Chinese families were recruited. Our cohort consists of 9 females and 12 males, between 5 months and 20 years old. The first symptom(s) appeared between 3 and 24 months. They were recorded to be either visual impairments (83%) or dilated cardiomyopathy (17%). Median time from symptom onset to seeking medical attention was 6 months (3-36 months) and the median time needed to reach the final molecular diagnosis is 54 months (6-240 months). System involvement at the time of the survey was as follows: visual symptoms (100%), hearing Impairment (67%), endocrine symptoms (43%), neurological symptoms (19%), hepatic symptoms (14%), and renal Involvement (14%). These findings are comparable to data reported in the literature. However, the proportion of subjects with cognitive impairment (33%) and behavioral problems (19%) were higher. Thirty-three unique mutations were identified in the ALMS1 gene, of which 18 are novel mutations classified as pathogenic/likely pathogenic according to the American College of Medical Genetics (ACMG) guideline. Four recurrent mutations were identified in the cohort, in particular; c.2084C>A, p. (Ser695Ter), is suggestive to be a founder mutation in people of Chinese ancestry. The participation of AS subjects of differing ethnicities is essential to improve the algorithm in facial recognition/phenotyping, as well as to understand the mutation spectrum beyond than just those of European ancestry.
    Matched MeSH terms: DNA Mutational Analysis/methods
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