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Nonclonal Chromosomal Aberrations in Childhood Leukemia Survivors

Chin TF, Ibrahim K, Thirunavakarasu T, Azanan MS, Oh L, Lum SH, et al.

Fetal Pediatr Pathol, 2018 Aug;37(4):243-253.
PMID: 30273079 DOI: 10.1080/15513815.2018.1492054

BACKGROUND: Survivors of childhood cancer are at risk of developing a second malignancy. One possible mechanism for neoplastic transformation of cells is through induction of persistent genomic instability. This study aims to seek evidence of chromosomal instability in long-term childhood leukemia survivors (CLS) in one of the largest pediatric academic oncology centers in South East Asia.
METHODS: 50 asymptomatic (subjects have remained leukemia-free since treatment cessation) CLS and 50 healthy controls were recruited in this cross-sectional study. Of 50 CLS, 44 had acute lymphoblastic leukemia and 6 had acute myeloid leukemia. G-banded karyotyping was performed on unstimulated peripheral blood leukocytes of all subjects.
RESULTS: CLS had significantly higher occurrence of karyotypic abnormalities compared to controls. Five CLS harbored six nonclonal abnormalities (mostly aneuploidy) while none were found in controls.
CONCLUSION: Subpopulations with nonclonal chromosomal aberrations were present in peripheral blood leukocytes of our cohort of childhood leukemia long-term survivors.

Matched MeSH terms: Abnormal Karyotype*
The systematic status of Gonocephalus robinsonii Boulenger, 1908 (Squamata: Agamidae: Draconinae)

Denzer W, Manthey U, Mahlow K, Böhme W

Zootaxa, 2015;4039(1):129-44.
PMID: 26624470 DOI: 10.11646/zootaxa.4039.1.5

The generic assignment of the draconine lizard Gonocephalus robinsonii from the highlands of West-Malaysia has been uncertain since the original description. Here we present a study based on morphology, previously published karyotype data and molecular phylogenetics using 16S rRNA sequences to evaluate the systematic status of G. robinsonii. As a result we describe Malayodracon gen. nov. to accommodate the species.

Matched MeSH terms: Karyotype
Fulltext Karyotypic and mtDNA based characterization of Malaysian water buffalo

Shaari N'AL, Jaoi-Edward M, Loo SS, Salisi MS, Yusoff R, Ab Ghani NI, et al.

BMC Genet, 2019 03 25;20(1):37.
PMID: 30909863 DOI: 10.1186/s12863-019-0741-0

BACKGROUND: In Malaysia, the domestic water buffaloes (Bubalus bubalis) are classified into the swamp and the murrah buffaloes. Identification of these buffaloes is usually made via their phenotypic appearances. This study characterizes the subspecies of water buffaloes using karyotype, molecular and phylogenetic analyses. Blood of 105 buffaloes, phenotypically identified as swamp, murrah and crossbred buffaloes were cultured, terminated and harvested using conventional karyotype protocol to determine the number of chromosomes. Then, the D-loop of mitochondrial DNA of 10 swamp, 6 crossbred and 4 murrah buffaloes which were identified earlier by karyotyping were used to construct a phylogenetic tree was constructed.
RESULTS: Karyotypic analysis confirmed that all 93 animals phenotypically identified as swamp buffaloes with 48 chromosomes, all 7 as crossbreds with 49 chromosomes, and all 5 as murrah buffaloes with 50 chromosomes. The D-loop of mitochondrial DNA analysis showed that 10 haplotypes were observed with haplotype diversity of 0.8000 ± 0.089. Sequence characterization revealed 72 variables sites in which 67 were parsimony informative sites with sequence diversity of 0.01906. The swamp and murrah buffaloes clearly formed 2 different clades in the phylogenetic tree, indicating clear maternal divergence from each other. The crossbreds were grouped within the swamp buffalo clade, indicating the dominant maternal swamp buffalo gene in the crossbreds.
CONCLUSION: Thus, the karyotyping could be used to differentiate the water buffaloes while genotypic analysis could be used to characterize the water buffaloes and their crossbreds.

Matched MeSH terms: Karyotype
Heterosis without selectional coadaptation inDrosophila ananassae

Singh BN

Theor Appl Genet, 1985 Jul;69(4):437-41.
PMID: 24253913 DOI: 10.1007/BF00570914

The relative viabilities of homozygous and heterozygous karyotypes were measured by making crosses between strains ofD. ananassae homozygous for ST or inverted gene orders in the second and third chromosomes. The strains utilized during the present study originated from widely separated localities in India, Kuala Lumpur and Kota Kinabaru, Malaysia and Chian Mai, Thailand. The presence of heterosis in many interpopulation crosses is evident from the results which show that the inversion heterozygotes formed by chromosomes coming from distant populations exhibit heterosis. On the other hand, heterosis is absent in two intrapopulation crosses. Thus the present results provide evidence that heterozygosis for many genes and gene complexes does produce high fitness without previous selectional coadaptation.

Matched MeSH terms: Karyotype
Optimization of ultraviolet irradiation of Clarias gariepinus (Burchell, 1822) eggs for androgen production

Okomoda VT, Nursyaza HJ, Samuel IO, Hassan A, Oladimeji AS, Abol-Munafi AB, et al.

Zygote, 2021 Jun;29(3):223-228.
PMID: 33446295 DOI: 10.1017/S0967199420000829

The optimum distance and duration of ultraviolet (UV) irradiation for the complete inactivation of African catfish Clarias gariepinus egg nucleus was investigated in this study. The UV light was suspended above the unfertilized eggs at four distances (5, 10, 20 and 30 cm) and for five durations (1, 2, 3, 4 and 5 min). Then, the irradiated eggs were activated with sperm from diploid C. gariepinus and cold shocked at 5°C for 5 min just moments before cell cleavage. Ploidy analysis was performed using karyotype chromosome counting. The results obtained suggested that the further the distance, the better the hatchability rate, however prolonged duration seemed to significantly reduced hatchability. All treatments with surviving progenies at the end of the study showed evidence of successfully diploid gynogen (2n = 56) induction at different percentages. However, the optimal protocol that gave a moderately high hatchability/survival rate and completely induced gynogens was exposure of the eggs to UV irradiation at 20 cm for 1 min. It was concluded that the distance and duration of UV irradiation affects gynogenetic induction in African catfish C. gariepinus.

Matched MeSH terms: Karyotype
Fulltext Chromosome karyotype analysis of cultivate somatic cells of ganjia sheep

Liu Meng, Ding Gongtao, Roziah Bt. Kambol

Science Letters, 2016;10(1):8-10.
MyJurnal

Cytogenetics studies in domestic animal are
gaining importance because of their genetics and implication in
breeding programmes. The present study describes the
chromosome number and karyotypic characteristics of Ganjia
sheep and comparison between males and females breeds. We
adopt the method of cultivating somatic cells, and analyzed the
chromosome karyotype of the Ganjia sheep. The result
indicates the diploid chromosome of the Gangia sheep is 2n=54,
in which 26 pairs of autosomes and a pair of sex chromosome
were observed. Result indicates all autosomes are tip silk. The X
chromosome was acrocentric and largest except the first three
pairs that were metacentric. The Y chromosome was the
smallest, biarmed and probably metacentric chromosome.

Matched MeSH terms: Karyotype
Fulltext Antigen expression pattern of acute promyelocytic leukaemia cases in Malaysia

Ambayya A, Zainina S, Salmiah MS, Sabariah MN

Med J Malaysia, 2014 Apr;69(2):64-9.
PMID: 25241814 MyJurnal

INTRODUCTION: Acute Promyelocytic Leukaemia (APL) is associated with devastating coagulopathy and life threatening condition which requires immediate medical attention. It is crucial to establish an expedited diagnosis as early therapeutic intervention has led to optimal patient management. In this study, we assessed the type and frequency of antigen expressions in APL and correlated these findings with genetic studies.

METHODS: Multiparametric immunophenotyping was performed on 30 samples and findings were correlated with karyotypes, FISH for t(15;17) translocation and RT-PCR for PML-RARΑ for detection of breakpoint cluster regions (bcr1,bcr2 and bcr3).

RESULTS: On SSC/CD45, APL cells displayed high to moderate SSC, with the expression of CD33 (100%), CD13 (96.8%), cMPO (71%) but lacked CD34 (3.2%) and HLA-DR (9.7%). Aberrant expression of CD4 was seen in 12.9% and CD56 in 6.5% of the cases. A significant association between cumulative aberrant antigen expression and bcr1 were observed bcr1 (X2(2) =6.833,p.05) and (X2(2)=4.599,p>.05) respectively.

CONCLUSIONS: Flow cytometry is a rapid and effective tool in detecting APL. It is interesting to note that there is significant association between cumulative aberrant antigen expression and genotype analysis. Further validation is required to corroborate this relationship.

Matched MeSH terms: Karyotype
Fulltext Deciphering the Evolutionary History of Arowana Fishes (Teleostei, Osteoglossiformes, Osteoglossidae): Insight from Comparative Cytogenomics

Cioffi MB, Ráb P, Ezaz T, Bertollo LAC, Lavoué S, Oliveira EA, et al.

Int J Mol Sci, 2019 Sep 02;20(17).
PMID: 31480792 DOI: 10.3390/ijms20174296

Arowanas (Osteoglossinae) are charismatic freshwater fishes with six species and two genera (Osteoglossum and Scleropages) distributed in South America, Asia, and Australia. In an attempt to provide a better assessment of the processes shaping their evolution, we employed a set of cytogenetic and genomic approaches, including i) molecular cytogenetic analyses using C- and CMA3/DAPI staining, repetitive DNA mapping, comparative genomic hybridization (CGH), and Zoo-FISH, along with ii) the genotypic analyses of single nucleotide polymorphisms (SNPs) generated by diversity array technology sequencing (DArTseq). We observed diploid chromosome numbers of 2n = 56 and 54 in O. bicirrhosum and O. ferreirai, respectively, and 2n = 50 in S. formosus, while S. jardinii and S. leichardti presented 2n = 48 and 44, respectively. A time-calibrated phylogenetic tree revealed that Osteoglossum and Scleropages divergence occurred approximately 50 million years ago (MYA), at the time of the final separation of Australia and South America (with Antarctica). Asian S. formosus and Australian Scleropages diverged about 35.5 MYA, substantially after the latest terrestrial connection between Australia and Southeast Asia through the Indian plate movement. Our combined data provided a comprehensive perspective of the cytogenomic diversity and evolution of arowana species on a timescale.

Matched MeSH terms: Karyotype
Test for association between dieldrin resistance and 2La inversion polymorphism in Anopheles coluzzii from Lagos, Nigeria

Adeogun AO, Brooke BD, Olayanju DR, Adegbehingbe K, Oyeniyi TA, Olakiigbe AK, et al.

Trop Biomed, 2019 Sep 01;36(3):587-593.
PMID: 33597480

The assortment of paracentric chromosomal inversion 2La is associated with the maintenance of dieldrin resistance in laboratory colonies of the malaria vector Anopheles gambiae. This association has not been tested in field populations. The aim of this study was to test the association between inversion 2La and dieldrin resistance in a field population of An. coluzzii in Nigeria. Field collected immature stages of Anopheles were raised to adults and exposed to 4% dieldrin according to WHO criteria. Knockdown was recorded at 10 min intervals for 1 hour and final mortality was recorded 24 hours post exposure. Species and inversion 2La diagnostic PCR assays were conducted on the resistant and susceptible mosquitoes. The mosquitoes were highly resistant to 4% dieldrin (17.1% knock down and 25.7% final mortality; KDT50 and KDT95 calculated as 170 and 1, 514 minutes respectively). Frequencies of 2La in both the resistant and susceptible cohorts assorted within HardyWeinberg estimates (χ2=1.32, p=0.8 for dead/susceptible mosquitoes and χ2=2.54, p=0.5 for survivors or resistant mosquitoes). However, a higher number of heterozygous mosquitoes were observed in the resistant cohort compared to the susceptible, with significant variation in karyotype frequencies (χ2=11.08, DF=2, p<0.05) and a significantly higher frequency of the 2La inversion arrangement in the resistant cohort (Pearson's χ2 = 4.58, p = 0.03.). These data are the first to associate paracentric chromosome inversion 2La and dieldrin resistance in field population of An. coluzzii. Dieldrin resistance shows a weak but significant association with 2La whose assortment is affected by positive heterosis. Variation in the assortment of 2La inversion arrangements between resistant and susceptible cohorts of this An. coluzzii population suggests that dieldrin resistance is at least partially linked to inversion 2La which may explain the persistence of dieldrin resistance in this population despite a significant absence of selection for resistance to this insecticide.

Matched MeSH terms: Karyotype
Fulltext Concomitant t(8;21) and trisomy 4 in a patient with acute myeloid leukemia (aml)

Phan, CL, Ong, TC, Chang, KM, Zubaidah, Z., Puteri Jamilatul, N.M.B.

Medicine & Health, 2010;5(1):45-48.
MyJurnal

The t(8;21)(q22;q22) is a frequently occurring aberration in acute myeloid leukemia (AML) (18-20%) and usually correlate with French-America-British (FAB) M2 subtype. Several studies showed that patients carrying this abnormality demonstrated good response to standard chemotherapy but also have a high incidence of disease relapse. Trisomy 4 is a rare and specific chromosomal abnormality occurring in AML M2 or M4 of the FAB subtypes. We report a case of a 33-year-old female with an apparently clinical and hematologic diagnosis of acute promyelocytic leukemia (APL) in whom cytogenetic analysis revealed an abnormal karyotype with trisomy 4, in addition to t(8;21). Trisomy 4 and t(8;21) in a patient with AML is rare. The significance of t(8;21) with trisomy 4 in AML are unclear but patients bearing this abnormality are associated with a poor prognosis.

Matched MeSH terms: Abnormal Karyotype
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: Karyotype
Fulltext A cryptic species of the Tylonycteris pachypus complex (Chiroptera: Vespertilionidae) and its population genetic structure in southern China and nearby regions

Huang C, Yu W, Xu Z, Qiu Y, Chen M, Qiu B, et al.

Int J Biol Sci, 2014;10(2):200-11.
PMID: 24550688 DOI: 10.7150/ijbs.7301

Three distinct bamboo bat species (Tylonycteris) are known to inhabit tropical and subtropical areas of Asia, i.e., T. pachypus, T. robustula, and T. pygmaeus. This study performed karyotypic examinations of 4 specimens from southern Chinese T. p. fulvidus populations and one specimen from Thai T. p. fulvidus population, which detected distinct karyotypes (2n=30) compared with previous karyotypic descriptions of T. p. pachypus (2n=46) and T. robustula (2n=32) from Malaysia. This finding suggested a cryptic Tylonycteris species within T. pachypus complex in China and Thailand. Morphometric studies indicated the difficulty in distinguishing the cryptic species and T. p. pachypus from Indonesia apart from the external measurements, which might be the reason for their historical misidentification. Based on 623 bp mtDNA COI segments, a phylogeographic examination including T. pachypus individuals from China and nearby regions, i.e., Vietnam, Laos, and Cambodia, was conducted to examine the population genetic structure. Genealogical and phylogeographical results indicated that at least two diverged lineages existed in these regions (average 3.4 % of Kimura 2-parameter distances) and their population structure did not match the geographic pattern. These results suggested that at least two historical colonizations have occurred by the cryptic species. Furthermore, through integration of traditional and geometric morphological results, morphological differences on zygomatic arches, toothrows and bullae were detected between two lineages in China. Given the similarity of vegetation and climate of Guangdong and Guangxi regions, we suggested that such differences might be derived from their historical adaptation or distinct evolutionary history rather than the differences of habitats they occurred currently.

Matched MeSH terms: Karyotype
Fulltext Case Report of an Adult Female with Neglected Congenital Adrenal Hyperplasia (CAH)

Krishnan GD, Yahaya N

J ASEAN Fed Endocr Soc, 2018;33(2):199-201.
PMID: 33442128 DOI: 10.15605/jafes.033.02.14

An apparently well 27-year-old phenotypically male adult was seen at the endocrine clinic for gender assignment. Patient had been raised as a male and identifies as such. Abdominal CT scan showed a unilateral left adrenal mass and karyotyping revealed 46 XX female karyotype. She was diagnosed to have simple virilizing CAH and needed thorough counselling with subsequent management by a multidisciplinary team.

Matched MeSH terms: Karyotype
47 XYY and morning glory syndrome--a unique association

Chew FL, Visvaraja S

J AAPOS, 2009 Aug;13(4):406-7.
PMID: 19487143 DOI: 10.1016/j.jaapos.2009.02.007

47 XYY syndrome is a sporadic condition in which the human male receives an extra Y chromosome. Few ocular associations have been documented. The authors report the first case of 47 XYY associated with morning glory syndrome, frontonasal meningoencephalocele, and midfacial defects.

Matched MeSH terms: XYY Karyotype/genetics*
Fulltext Double Philadelphia chromosome-positive B acute lymphoblastic leukaemia in an elderly patient

Tang YL, Raja Sabudin RZ, Leong CF, Ko CC, Chia WK, Salwati S, et al.

Malays J Pathol, 2015 Dec;37(3):275-9.
PMID: 26712675 MyJurnal

A rare case of double Philadelphia chromosome-positive B Acute lymphoblastic Leukaemia (B-ALL) is reported here. A 60-year-old lady presented with one month history of fever, submandibular lymphadenopathy, loss of appetite and weight loss. Physical examination revealed multiple palpable cervical lymph nodes. Blood film showed leucocytosis with 72% blasts. Bone marrow assessment confirmed a diagnosis of B-ALL with presence of double Philadelphia (Ph) chromosomes. As she was very ill, she was initially treated with an attenuated regimen of induction chemotherapy consisting of rituximab, cyclophosphamide, vincristine and prednisolone (R-CVP) along with intrathecal chemotherapy comprising methotrexate, cytarabine and hydrocortisone. Bone marrow examination post-induction chemotherapy showed >5% blasts. She was subsequently re-induced with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP) along with intrathecal chemotherapy, following which she went into complete remission. Consolidation chemotherapy consisting of methotrexate, methylprednisolone, cytarabine, intrathecal chemotherapy and imatinib was subsequently administered followed by maintenance chemotherapy consisting of vincristine, prednisolone and imatinib (IDEAMOP). She developed spontaneous bruises and relapsed four months into her maintenance chemotherapy with 90% blasts in the bone marrow which was treated with fludarabine, cytarabine and granulocyte colony stimulating factor (FLAG). Unfortunately she developed neutropenic sepsis which was complicated by invasive lung aspergillosis. Bone marrow examination post-FLAG showed 80% blasts. Despite aggressive antifungal therapy, her lung infection worsened and she finally succumbed to her illness 13 months after the initial diagnosis. We highlight a rare case of elderly B-ALL with double Ph chromosomes which carries a poor prognosis despite aggressive treatment for the disease and its complications.

Matched MeSH terms: Abnormal Karyotype
Fulltext Outcome of pregnancy in chromosomally normal foetus with increased nuchal translucency

Ranjit, S., Carol, P., Kellie, C., Pauline, M., Renuka, S.

International Medical Journal Malaysia, 2018;17(1):55-62.
MyJurnal

Objective: The aim of this study is to evaluate the outcome of pregnancy in prenatal and postnatal period of pregnancy complicated with thick nuchal translucency but normal karyotype. Methods: This is a retrospective study of 119 singleton pregnancies with increased NT (NT > 2.5mm) but a normal karyotype over a 3 year period. The records of ultrasound at 18-20 and 25-26 weeks’, antenatal and postnatal details were reviewed. The developmental and health outcomes of the surviving children were obtained through telephone conversation with the family. Adverse outcome such as miscarriages, termination of pregnancy, intrauterine death, structural anomalies and neurodevelopment delay were analysed. Results: Out of 119 foetuses with increased NT but normal karyotype, 11.8% of pregnancies ended with miscarriages, termination of pregnancy and intrauterine death. 89.9% foetuses were structurally normal. 12.9% presented with structural anomalies in the second-trimester ultrasound scan. 81.8% showed major malformations, out of which 44% consisted of heart defects. 1% of foetuses were syndromic and 1.9% had developmental delay. 96.8% of foetuses with NT equal to or greater than the 95th percentile (3.4mm) and 80% with NT equal to or greater than the 99 percentile (5.5mm) had a normal outcome. 50% of foetuses with thickened nuchal fold had a poor outcome. Postnatal follow-up was established for all infants and toddlers, and abnormalities were observed in 5.6% of them. Chances of having a live and healthy infant decreases with increased NT, corresponding to 80% for NT equal to or greater than 5.5mm. Conclusion: We have provided data that may help in the counselling of parents and increasing their confidence on a favourable pregnancy outcome. In cases with increased nuchal translucency but normal karyotype, the chances of normal pregnancy success rate is 89.9%. Parents can be reassured that thickened nuchal translucency with a normal karyotype and normal targeted ultrasound between 20-22 weeks gestation, the risk of adverse perinatal outcome and postnatal developmental delay is not increased in comparison with that of the general population. This seems to be the case for all degrees of increased nuchal translucency.

Matched MeSH terms: Karyotype
Fulltext A case study of distinctive phenotypes arising from emanuel syndrome in two karyotypically identical patients

Mot Yee Yik, Rabiatul Basria S.M.N. Mydin, Emmanuel Jairaj Moses, Shahrul Hafiz Mohd Zaini, Abdul Rahman Azhari, Narazah Mohd Yusoff

Malaysian Journal of Medicine and Health Sciences, 2020;16(102):78-80.
MyJurnal

Emanuel syndrome, also referred to as supernumerary der(22) or t(11;22) syndrome, is a rare genomic syndrome. Patients are normally presented with multiple congenital anomalies and severe developmental disabilities. Affected newborns usually carry a derivative chromosome 22 inherited from either parent, which stems from a balanced translocation between chromosomes 11 and 22. Unfortunately, identification of Emanuel syndrome carriers is diffi- cult as balanced translocations do not typically present symptoms. We identified two patients diagnosed as Emanuel syndrome with identical chromosomal aberration: 47,XX,+der(22)t(11;22)(q24;q12.1)mat karyotype but presenting variable phenotypic features. Emanuel syndrome patients present variable phenotypes and karyotypes have also been inconsistent albeit the existence of a derivative chromosome 22. Our data suggests that there may exist ac- companying genetic aberrations which influence the outcome of Emanuel syndrome phenotypes but it should be cautioned that more patient observations, diagnostic data and research is required before conclusions can be drawn on definitive karyotypic-phenotypic correlations.

Matched MeSH terms: Karyotype
Fulltext The role of conventional and molecular cytogenetics in the diagnosis of microdeletion syndromes

Salwati Shuib, Sharifah Noor Akmal, Zarina Abdul Latif, Nor Zarina Zainal Abidin, Zubaidah Zakaria

Medicine & Health, 2006;1(1):45-52.
MyJurnal

In this report we demonstrate the role of fluorescence in situ hybridisation (FISH) and conventional cytogenetic methods in clinically and cytogenetically confirmed cases of microdeletion syndromes. A total of nine cases were referred to the Cytopathology and Cytogenetic Unit, Hospital Universiti Kebangsaan Malaysia (HUKM) from 2002 to 2004. They include three Prader-Willi syndrome, three DiGeorge syndrome, one Williams syndrome, one Miller-Dieker syndrome and one Kallmann syndrome. Blood samples from the patients were cultured and harvested following standard procedures. Twenty metaphases were analysed for each of the cases. FISH analysis was carried out for all the cases using commercial probes (Vysis, USA): SNRPN and D15S10 for Prader-Willi syndrome, LIS1 for Miller Dieker syndrome, ELN for Williams syndrome, KAL for Kallmann syndrome, TUPLE 1 and D22S75 for DiGeorge syndrome. Conventional cytogenetic analysis revealed normal karyotypes in all but one case with structural abnormality involving chromosomes 9 and 22. FISH analysis showed microdeletions in all of the nine cases studied. This study has accomplished two important findings ie. while the FISH method is mandatory in ruling out microdeletion syndromes, conventional cytogenetics acts as a screening tool in revealing other chromosomal abnormalities that may be involved with the disease.

Matched MeSH terms: Karyotype
Fulltext Karyotype pattern and maternal age distribution in down syndrome patients analyzed at Human Genome Centre, University Sains Malaysia, Kelantan

Siti Mariam I, Suhaida MA, Tarmizi AB, Norhasimah M, Nor Atifah MA, Kannan, T. P., et al.

Buletin Persatuan Genetik Malaysia, 2006;12(1):6-9.
MyJurnal

Down Syndrome (DS), is a complex genetic disease resulting from the presence of 3 copies of chromosome 21. It is the most common autosomal abnormality among live births and the most commonly recognized genetic cause of mental retardation. The only well established risk factor for DS is advanced maternal age. The Human Genome Center , University Sains Malaysia, Kelantan has been carrying out cytogenetic studies in DS patients. Here we, report the karyotype pattern of Down Syndrome patients in correlation with maternal age, among referral cases to our Center.

Matched MeSH terms: Karyotype
Down syndrome as a result of de novo robertsonian translocation involving chromosome 14 and 21: a case report

Norhasimah, M.M., Ahmad Tarmizi, A.B., Azman, B.A., Zilfalil, B.A., Ankathil, R.

Malaysian Journal of Paediatrics and Child Health, 2007;15(1):46-49.
MyJurnal

Generally, the karyotype profile of Down Syndrome has been reported to be full trisomy 21 in 92% of patients, mosaic trisomy 21 in 4% of patients and translocation involving chromosome 21 in 4% of patients in most of the population groups worldwide. But, karyotype analysis of 149 DS patients at the Human Genome Center, USM, during the past five years revealed that free trisomy accounted for 94.6%, mosaic trisomy 21 for 4.7% and translocation involving chromosome 21 in 0.7% of the Down Syndrome etiology in North East Malaysian population, indicating a low frequency of translocation DS in this region. Here, we report one case of translocation Down Syndrome encountered during karyotype analysis of 149 DS cases. Karyotype showed a robertsonian translocation where an entire extra chromosome 21 was attached to the centromere of one of the chromosome 14, resulting in a derivative chromosome 14 with attached chromosome 21. Karyotype analysis of the parents revealed a normal 46,XY pattern for father and 46,XX pattern for mother indicating that this robertsonian translocation had arisen de novo either prior to or at conception.

Matched MeSH terms: Karyotype

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