Displaying publications 21 - 40 of 76 in total

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  1. Fulltext Prevalence of chromosomal anomalies of the mentally retarded--report of a study of 124 institutionalised children in Kuala Lumpur
    Noor PJ, Chin YM, Ten SK, Hassan K
    Singapore Med J, 1987 Jun;28(3):235-40.
    PMID: 2958941
    A cytogenetic survey 01 124 children in lour special schools for the mentally handicapped was carried out to determine the contribution of chromosomal abnormalities to the aetiology of mental retardation in these children. All the children were karyotyped employing the G·banding technique 01 43 (34.7%) with an abnormal chromosome complement, 40 had Down's Syndrome, and 3 had other chromosomal abnormalities, namely a translocation 1;17, a mosaic male/trisomy 18 and a Klinefelter's syndrome. Polymorphic variants involving chromosomes 1, 9, and 14 were also observed. Two other children showed variants of the Y chromosome (one a small Y and the other a metacentric Y). The possible contribution by these abnormal variants to mental retardation is discussed. Details of the abnormal cytogenetic findings are reported.
    Matched MeSH terms: Karyotyping
  2. Karyotype of Malayan Gaur (Bos gaurus hubbacki), Sahiwal-Friesian cattle and Gaur x cattle hybrid backcrosses
    Adbullah MH, Idris I, Hilmi M
    Pak J Biol Sci, 2009 Jun 15;12(12):896-901.
    PMID: 19777782
    Interspecific hybridization has been reported for a wide variety of vertebrate species either spontaneous or by organized crossing of bovine species. The hybrids were often carrying intermediate characters genetically and phenotypically of the parents. Thus, status information of both aspects is valuable in animal production for selection and breeding management. The Gaur-cattle hybrids was reported to be superior in production value compared to their parent cattle but fertility status was still questionable. The project was abandoned due to their fertility issue and the hybrids were kept within the cattle in a dairy farm. Cytogenetic status and breeding record of the remaining herd were unavailable since then. The herd was then translocated to a deer farm (PTH Lenggong) and kept freely in the paddock. Recently, two female calves were born via inter se mating. Peripheral blood cultures of Malayan Gaur, Sahiwal-Friesian cattle and Gaur x cattle hybrid backcrosses were analyzed via Giemsa stained metaphase. The Gaur and cattle were having diploid chromosome number (2n) of 56 and 60, respectively. Interestingly, the backcrosses from the hybrids by cattle bulls were found to have two chromosome arrangements, which are 2n = 58 and 2n = 60.
    Matched MeSH terms: Karyotyping
  3. Presumptive X monosomy in black rats from Malaya
    Hoi-Sen Y
    Nature, 1971 Aug 13;232(5311):484-5.
    PMID: 4937212
    Matched MeSH terms: Karyotyping
  4. Dermatoglyphics of Down's syndrome patients in Malays--a comparative study
    Than M, Myat KA, Khadijah S, Jamaludin N, Isa MN
    Anthropol Anz, 1998 Dec;56(4):351-65.
    PMID: 10027045
    There has been no recent report on the dermatoglyphics of the Malays (normal population as well as patients with Down's syndrome). A study on the frequencies of the dermal patterns (dermatoglyphics) of the digits, palms and hallucal areas was done therefore in 40 Malay patients with Down's syndrome and 200 unrelated normal controls. Only the patients with the standard 21 trisomy karyotype were included in the study. Comparison was made with the published data on studies done in various racial groups. Significant differences of the dermal patterns were found not only between the controls but also among patients of different races.
    Matched MeSH terms: Karyotyping
  5. Fulltext Abnormalities of chromosome 11Q in three cases of acute myeloid leukemia
    Ten SK, Khor MK, Khalid H, Lin HP, Ng SC, Cheong SK, et al.
    Singapore Med J, 1992 Apr;33(2):164-6.
    PMID: 1621121
    The haematological findings and case history of 3 patients with the association of acute myeloid leukemia and translocation involving the long arm of chromosome no. 11 are presented. The recipient chromosome for the translocated material from chromosome 11 differs in all the three cases being namely chromosomes 1, 10 and 17.
    Matched MeSH terms: Karyotyping
  6. Chromosomal evolution in the lizard genus Varanus (reptilia)
    King M, King D
    Aust. J. Biol. Sci., 1975 Feb;28(1):89-108.
    PMID: 1164258
    The karyotypes have been determined of 16 of the 32 species of the genus Varanus, including animals from Africa, Israel, Malaya and Australia. A constant chromosome number of 2n = 40 was observed. The karyotype is divided into eight pairs of large chromosomes and 12 paris of microchromosomes. A series of chromosomal rearrangements have become established in both size groups of the karyotype and are restricted to centromers shifts, probably caused by pericentric inversion. Species could be placed in one of six distinct karyotype groups which are differentiated by these rearrangements and whose grouping does not always correspond with the current taxonomy. An unusual sex chromosome system of the ZZ/ZW type was present in a number of the species examined. The evolutionary significance of these chromosomal rearrangements, their origin and their mode of establishment are discussed and related to the current taxonomic groupings. The most likely phylogenetic model based on chromosome morphology, fossil evidence and the current distribution of the genus Varanus is presented.
    Matched MeSH terms: Karyotyping
  7. Karyotypes of Hapalomys and Pithecheir (rodentia: Muridae) from peninsular Malaysia
    Yong HS, Dhaliwal SS, Lim BL
    Cytologia (Tokyo), 1982 Dec;47(3-4):535-8.
    PMID: 7166052
    Matched MeSH terms: Karyotyping
  8. Increased genome size is caused by heterochromatin addition in two non-related bat species, Hesperoptenus doriae and Philetor brachypterus (Vespertilionidae, Chiroptera, Mammalia)
    Volleth M, Greilhuber J, Heller KG, Müller S, Yong HS, Loidl J
    Chromosoma, 2023 Nov;132(4):269-288.
    PMID: 37322170 DOI: 10.1007/s00412-023-00802-w
    The average genome size (GS) of bats, which are the only mammals capable of powered flight, is approximately 18% smaller than that of closely related mammalian orders. The low nuclear DNA content of Chiroptera is comparable to that of birds, which are also characterized by a high metabolic rate. Only a few chiropteran taxa possess notable amounts of constitutive heterochromatin. Here, we studied the karyotypes of two non-related vesper bat species with unusually high amounts of constitutive heterochromatin: Hesperoptenus doriae and Philetor brachypterus. Conventional staining methods and whole-chromosome painting with probes derived from Myotis myotis (2n = 44), showing a karyotype close to that of the presumed ancestor of Vespertilionidae, revealed Robertsonian fusions as the main type of rearrangement leading to the exceptionally reduced diploid chromosome number of 2n = 26 in both species. Moreover, both karyotypes are characterized by large blocks of pericentromeric heterochromatin composed of CMA-positive and DA-DAPI-positive segments. In H. doriae, the heterochromatin accumulation has resulted in a genome size of 3.22 pg (1C), which is 40% greater than the mean genome size for the family. For P. brachypterus, a genome size of 2.94 pg was determined, representing an increase of about 28%. Most notably, in H. doriae, the presence of additional constitutive heterochromatin correlates with an extended mitotic cell cycle duration in vitro. A reduction in diploid chromosome number to 30 or lower is discussed as a possible cause of the accumulation of pericentromeric heterochromatin in Vespertilionidae.
    Matched MeSH terms: Karyotyping
  9. Fulltext Polymerase chain reaction analysis as a rapid screening test for diagnosis of fragile x syndrome
    Phan, CL, Zubaidah, Z., Gregory, A.R.A., Ten, SK, Kamariah, M.N., Thilagavathi, S., et al.
    Medicine & Health, 2006;1(1):36-44.
    MyJurnal
    Fragile X syndrome is a result of an unstable expansion of (CGG)n trinucleotide sequences in the FMR-1 (Fragile X Mental Retardation 1) gene site at Xq27. In a normal person, n ranges from 6 to 40 repeats with an average of 30 repeats, whereas in a mutated FMR1 gene the sequence is repeated several times over (stuttering gene). Full mutation occurs when n equals 200 repeats or more. Where n equals 50 to 200 repeats, it is a premutation. Fragile X occurs when the FMR-1 gene is unable to make normal amounts of usable Fragile X Mental Retardation Protein, or FMRP. The amount of FMRP in the body is one factor that determines the severity of the Fragile X syndrome. A person with nearly normal levels of FMRP usually has mild or no symptoms, while a person with very little or no normal FMRP has more severe symptoms. The mechanism for the role of the FMRP gene is still being researched upon. However, it has been observed that large numbers of repeats (more than 200) inactivates the gene through a process of methylation and when the gene is inactivated, the cell may make little or none of the needed FMRP. Inheritance is X-linked with reduced penetrance and the frequency of occurrence goes up through generations. The phenotypic manifestations of fragile-X syndrome vary and are largely dependent on the size of the mutation or premutation. The identification of the fragile site on G banded metaphases is a time consuming and delicate process requiring experience and skill, however, molecular diagnosis using DNA analysis and Southern blotting, even though expensive, is more specific in determining the presence or absence of the gene. This study was aimed to establish a rapid polymerase chain reaction (PCR) based - touch down PCR, as a screening method for fragile X syndrome. A total of six cases were analysed. Of these, one was a known case of Fragile X (T1) diagnosed by conventional cytogenetics, two were from the latter’s family members namely, his mother (T2) and father (T3), and the other two (T4 and T5) were randomly selected from patients presenting with dysmorphic features and delayed development respectively. One normal control (TC) was included. Cytogenetic analyses for detection of the fragile site was carried out in all cases. Two culture systems were used, namely the synchronised lymphocyte culture and the folate - thymidine deficient culture. Stained metaphases from the fragile X cultures were screened for the presence of the fragile site on the X chromosome. G-banded karyotyping was done using an image analyser to exclude presence of chromosomal abnormalities. DNA was extracted from these samples and amplified by touch-down PCR. Cytogenetic analysis revealed a folate-sensitive fragile site in the affected male, but none in the other five samples. G-banded karyotyping exhibited no additional chromosomal abnormalities. All extracted DNA samples were successfully amplified. Five of the samples showed presence of the product at the expected band at 552bp, excluding the presence of an expansion of CGG segment of the FMR-1 gene. The absence of a band in an affected individual, suggested a fully mutated allele of FRAXA (Folate Sensitive Fragile Site at Xq28). We succeeded in establishing a slightly modified touch-down PCR analysis. Our study indicates that PCR testing offers a rapid and specific method for screening of normal allele and full mutation of the fragile X gene. We suggest this technique to be applied as a complementary tool for cytogenetic analysis to detect the FRAXA gene.
    Matched MeSH terms: Karyotyping
  10. Nematode isoenzyme studies and cytogenetics
    Yong HS, Mak JW
    Southeast Asian J. Trop. Med. Public Health, 1988 Mar;19(1):131-5.
    PMID: 3043697
    The current information on isoenzyme studies of nematode parasites was reviewed. The genetic heterogeneity as reviewed by these studies was highlighted. Application of isoenzyme studies and the role of biotechnological techniques in isoenzyme studies was discussed, and the status of cytogenetic studies on nematode parasites was presented.
    Matched MeSH terms: Karyotyping/veterinary
  11. Rapid detection of prognostically important childhood acute lymphoblastic leukemia chimeric transcripts using multiplex SYBR green real-time reverse transcription PCR
    Ibrahim K, Daud SS, Seah YL, Yeoh AE, Ariffin H, Malaysia-Singapore Leukemia Study Group
    Ann Clin Lab Sci, 2008;38(4):338-43.
    PMID: 18988926
    Childhood acute lymphoblastic leukaemia (ALL) is a heterogenous disease in which oncogene fusion transcripts are known to influence the biological behaviour of the different ALL subtypes. Screening for prognostically important transcripts is an important diagnostic step in treatment stratification and prognostication of affected patients. We describe a SYBR-Green real-time multiplex PCR assay to screen for transcripts TEL-AML1, E2A-PBX1, MLL-AF4, and the two breakpoints of BCR-ABL (p190 and p210). Validation of the assay was based on conventional karyotyping results. This new assay provides a rapid, sensitive, and accurate detection method for prognostically important transcripts in childhood ALL.
    Matched MeSH terms: Karyotyping
  12. Fulltext Multiplexed automated digital quantification of fusion transcripts: comparative study with fluorescent in-situ hybridization (FISH) technique in acute leukemia patients
    Akhter A, Mughal MK, Elyamany G, Sinclair G, Azma RZ, Masir N, et al.
    Diagn Pathol, 2016 Sep 15;11(1):89.
    PMID: 27632978 DOI: 10.1186/s13000-016-0541-z
    The World Health Organization (WHO) classification system defines recurrent chromosomal translocations as the sole diagnostic and prognostic criteria for acute leukemia (AL). These fusion transcripts are pivotal in the pathogenesis of AL. Clinical laboratories universally employ conventional karyotype/FISH to detect these chromosomal translocations, which is complex, labour intensive and lacks multiplexing capacity. Hence, it is imperative to explore and evaluate some newer automated, cost-efficient multiplexed technologies to accommodate the expanding genetic landscape in AL.
    Matched MeSH terms: Karyotyping
  13. A Single Institution's Experience with Cytogenetic and MRD Outcomes in Pediatric Acute Lymphoblastic Leukemia
    Amjad A, Wali RM, Anjum S, Mansoor R
    J Coll Physicians Surg Pak, 2019 Jun;29(6):549-552.
    PMID: 31133155 DOI: 10.29271/jcpsp.2019.06.549
    OBJECTIVE: To determine the frequency of cytogenetic type and its significance in the prognostic outcome of the pediatric patients in acute lymphoblastic leukemia (ALL), aged 1 to 15 years, and also determine the importance of minimal residual disease (MRD) in the management of the condition.

    STUDY DESIGN: An observational study.

    PLACE AND DURATION OF STUDY: Pediatric Oncology Ward, Shaukat Khanum Cancer Hospital, Lahore, from January 2015 to July 2017.

    METHODOLOGY: Patients aged 1-15 years, diagnosed with ALL, were included. Studied variables were cytogenetic type and MRD outcome in patients with ALL. Patients under one year of age and more than 15 years, or those having comorbidities, were excluded.

    RESULTS: Total 150 patients' data were retrieved from the Hospital database. One hundred and thirty-three belonged to age 1 to 5 years group (89%) and 17 (11%) were in 5 to 10 years group. The mean age of the patient was 4.3 +3.1 years. One hundred and two (68%) were males; whereas, 48 (32%) were females. Pre B acute lymphoblastic leukemia was diagnosed in 139 (93%) patients and 11(7%) were diagnosed with Pre T acute lymphoblastic leukemia. Standard risk was observed in 120 (80%) patients and 30 (20%) patients were on high risk as per National Cancer Institute (NCI) Guidelines. Regimen A was used in 125 (83.3%), Regimen B in 16 (10.7%), and Regimen C in 9 (6%) patients. BCR-ABL was positive in 2 (1.30%), TEL-AML in 68 (45%), MLL in 5 (3.30%), and normal in 54 (36%). MRD at day 29 was negative in 40 (93%) and positive in 3 (7%). The karyotyping was done in 128 (85%) patients, out of which 68 (53%) were hyperploids, 41 (32%) euploid, and 19 (15%) were hypoploid. Death was observed in 22 (15%) patients. Nineteen (86%) deaths were due to fungal and bacterial sepsis; and disease-related deaths were noted in 3 (14%) patients.

    CONCLUSION: The role of MRD and cytogenetics in risk assessment has improved in the early prognosis determination.

    Matched MeSH terms: Karyotyping
  14. Fulltext Elucidating lineage-specific myelotoxicity and chromosomal aberration status in hydroquinone- exposed hematopoietic STEM / progenitor cells
    Julia Mohd Idris, Zariyantey Abd Hamid, Ng, Khen Eng, Chow, Paik Wah, Salwati Shuib, Mathialagan, Ramya Dewi
    Life Sciences, Medicine and Biomedicine, 2018;2(1):14-21.
    MyJurnal
    Benzene exposure has been associated with hematotoxicity and leukemogenicity. However, the impact of benzene exposure on complex microenvironment of Hematopoetic Stem Cells (HSCs) niche, comprising of HSCs and lineage-specific progenitors remains elusive. Thus, a study on benzene-targeting HSCs niche could uncover mechanism linking benzene to HSCs niche alteration. This study evaluates the lineage-specific responses following exposure to a benzene metabolite, namely hydroquinone (HQ) in targeting HSCs and myeloid-committed progenitors. Freshly isolated murine bone marrow cells (BMCs) were exposed to HQ at series of concentrations (0 – 50 μM) for 24 hours; followed by cell viability analysis using MTT assay. Chromosomal aberration (CA) status was determined using karyotyping analysis. Expression of surface antigen for HSCs (Sca-1) was confirmed by flow cytometer. Lineage-specific myelotoxicity was studied using the colony-forming unit (CFU) assay for the following myeloid progenitors: CFU granulocyte /erythrocyte /macrophage /megakaryocyte (CFU-GEMM), CFU-granulocyte/macrophage (CFU-GM), CFU-granulocyte (CFU-G), CFU-macrophage (CFU-M), CFU-erythroid (CFU-E) and Burst-forming unit erythroid (BFU-E). HQ reduced (p
    Matched MeSH terms: Karyotyping
  15. Fulltext Identification of Y Chromosomal Material in Turner Syndrome by Fluorescence In Situ Hybridisation (FISH)
    Reena Rahayu Md Zin, Sharifah Noor Akmal, Zubaidah Zakaria, Haut, Clarence Ko Ching, Siti Mariam Yusof, Julia Mohd Idris, et al.
    Medicine & Health, 2008;3(1):22-29.
    MyJurnal
    Turner syndrome is one of the most common chromosomal abnormalities affecting newborn females. More than half of patients with Turner syndrome have a 45X karyotype The rest of the patients may have structurally abnormal sex chromosomes or are mosaics with normal or abnormal sex chromosomes. Mosaicism with a second X sex chromosome is not usually of clinical significance. However, Turner syndrome patients having a second Y chromosome or Y chromosomal material are at risk of developing gonadoblastoma later in life. The aim of this study is to compare the results of conventional (karyotyping) and molecular cytogenetics (FISH), and discuss the advantages and limitations in the diagnosis of Turner syndrome. We also aim to compare the degree of mosaicism identified using conventional cytogenetics and FISH techniques. Conventional cytogenetics and FISH analyses were performed on eight peripheral blood samples of patients with Turner syndrome collected between 2004 and 2006. From this study, two out of eight patients with Turner syndrome were found to have the sex determining region on the Y chromosome (SRY) gene by FISH analysis. Our results showed that the rate of detection of mosaic cases in Turner syndrome was also increased to 88% after using the FISH technique. We concluded that FISH is more superior to conventional cytogenetics in the detection of the Y chromosomal material. FISH is also a quick and cost effective method in diagnosing Turner syndrome and assessing the degree of mosaicism.
    Matched MeSH terms: Karyotyping
  16. Molecular genetic diversity of the Saccharomyces yeasts in Taiwan: Saccharomyces arboricola, Saccharomyces cerevisiae and Saccharomyces kudriavzevii
    Naumov GI, Lee CF, Naumova ES
    Antonie Van Leeuwenhoek, 2013 Jan;103(1):217-28.
    PMID: 22941248 DOI: 10.1007/s10482-012-9803-2
    Genetic hybridization, sequence and karyotypic analyses of natural Saccharomyces yeasts isolated in different regions of Taiwan revealed three biological species: Saccharomyces arboricola, Saccharomyces cerevisiae and Saccharomyces kudriavzevii. Intraspecies variability of the D1/D2 and ITS1 rDNA sequences was detected among S. cerevisiae and S. kudriavzevii isolates. According to molecular and genetic analyses, the cosmopolitan species S. cerevisiae and S. kudriavzevii contain local divergent populations in Taiwan, Malaysia and Japan. Six of the seven known Saccharomyces species are documented in East Asia: S. arboricola, S. bayanus, S. cerevisiae, S. kudriavzevii, S. mikatae, and S. paradoxus.
    Matched MeSH terms: Karyotyping
  17. A variant e13a3 BCR-ABL1 fusion transcript in refractory adult B-cell acute lymphoblastic leukemia achieving complete remission with CAR-Tcell therapy
    Phan CL, Tan SN, Tan SM, Kadir SSSA, Ramli NLM, Lim TO, et al.
    Cancer Genet, 2021 01;250-251:20-24.
    PMID: 33220656 DOI: 10.1016/j.cancergen.2020.11.003
    Acute lymphoblastic leukemia (ALL) cases with e13a3 fusion transcripts are extremely rare. We report a 24-year-old male with Ph-positive (Ph+) ALL with an aberrant e13a3 fusion transcript treated with CD19-specific chimeric antigen receptor T-cell (CAR-T) therapy. He developed refractory disease post-chemotherapy induction, andreceived allogeneic hematopoietic stem cell transplantation (allo-HSCT) after salvage with imatinib in combination with chemotherapy regimen. Unfortunately, the patient relapsed after +90 days post-transplant. He was consented to CAR-T therapy trial and achieved complete remission, highlighting the efficacy of CAR-T treatment in relapsed-refractory B-ALL irrespective of the underlying genetic drivers in leukemia cells .
    Matched MeSH terms: Karyotyping
  18. Fulltext Supernumerary chromosomes in mosaic Turner syndrome
    Thong MK, Manonmani V, Norlasiah IS
    Med J Malaysia, 1996 Dec;51(4):487-90.
    PMID: 10968041
    The finding of a supernumerary or marker chromosome in a karyotype poses difficulty in genetic counselling. The true incidence and significance of this chromosomal aberration is unknown in Malaysia. We report two patients who presented with supernumerary chromosomes in mosaic Turner syndrome.
    Matched MeSH terms: Karyotyping
  19. Klinefelter's syndrome, a case report
    Kutty MK, Dutt AK, Lopez G, Ramanathan K, Pillay DR, Omar-Ahmad UD
    Med J Malaya, 1968 Sep;23(1):51-3.
    PMID: 4237557
    Matched MeSH terms: Karyotyping
  20. Fulltext True hermaphrodite--a case report
    Yip CH, Pathmanathan R
    Singapore Med J, 1996 Feb;37(1):117-8.
    PMID: 8783930
    A case report of a male true hermaphrodite with 46XX/46XY karyotype is presented. He was first diagnosed at the age of 9 years when he presented with hypospadias and a left undescended testis. He was lost to follow-up until he presented at the age of 23 years with bilateral gynaecomastia. A hormonal profile showed a low testosterone level, while a seminal assay showed very few sperms. However he claimed to be sexually active. A year later, after he got married, he began to complain of impotence. A review of the condition is presented.
    Matched MeSH terms: Karyotyping
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