MyMedR

Maternal gonosomal mosaicism in rare autosomal dominant SLFN14-related thrombocytopenia

Ang MP, Yeoh SL, Lim CH, Foo SL, Wong YW, Ch'ng GS

Br J Haematol, 2022 Dec;199(5):765-767.

Matched MeSH terms: Chromosome Disorders*

Fulltext Novel population specific autosomal copy number variation and its functional analysis amongst Negritos from Peninsular Malaysia

Mokhtar SS, Marshall CR, Phipps ME, Thiruvahindrapuram B, Lionel AC, Scherer SW, et al.

PLoS One, 2014;9(6):e100371.

PMID: 24956385 DOI: 10.1371/journal.pone.0100371

Copy number variation (CNV) has been recognized as a major contributor to human genome diversity. It plays an important role in determining phenotypes and has been associated with a number of common and complex diseases. However CNV data from diverse populations is still limited. Here we report the first investigation of CNV in the indigenous populations from Peninsular Malaysia. We genotyped 34 Negrito genomes from Peninsular Malaysia using the Affymetrix SNP 6.0 microarray and identified 48 putative novel CNVs, consisting of 24 gains and 24 losses, of which 5 were identified in at least 2 unrelated samples. These CNVs appear unique to the Negrito population and were absent in the DGV, HapMap3 and Singapore Genome Variation Project (SGVP) datasets. Analysis of gene ontology revealed that genes within these CNVs were enriched in the immune system (GO:0002376), response to stimulus mechanisms (GO:0050896), the metabolic pathways (GO:0001852), as well as regulation of transcription (GO:0006355). Copy number gains in CNV regions (CNVRs) enriched with genes were significantly higher than the losses (P value <0.001). In view of the small population size, relative isolation and semi-nomadic lifestyles of this community, we speculate that these CNVs may be attributed to recent local adaptation of Negritos from Peninsular Malaysia.

Matched MeSH terms: Chromosome Disorders/ethnology; Chromosome Disorders/genetics*

De novo ring chromosome 6 in a child with multiple congenital anomalies

Ahzad HA, Ramli SF, Loong TM, Salahshourifar I, Zilfalil BA, Yusoff NM

Kobe J Med Sci, 2010;56(2):E79-84.

PMID: 21063149

Ring chromosome 6, especially if it is de novo, is a rare occurrence. The phenotype of patients with ring chromosome 6 can be highly variable ranging from almost normal to severe malformations and mental retardation. The size and structure of the ring chromosome as well as the level of mosaicism are important factors in determining the clinical phenotype. Here we report an eight month-old child, a product of a non consanguineous marriage, who presented with developmental retardation, hypertelorism, microcephaly, flat occiput, broad nasal bridge, large ears, micrognathia, wide spaced nipples, protruding umbilicus, short stubby fingers, clinodactyly, single palmar crease, short neck with no obvious webbing, and congenital heart defect. Conventional karyotyping and Whole Chromosome Paint of the peripheral leukocytes showed 46,XY,r(6)(p25q27) karyotype with plausible breakpoints at p25 and q27 end. Conventional karyotyping of both parents showed normal karyotype. To the best of our knowledge, this is the first report of a Malay individual with ring chromosome 6, and this report adds to the collective knowledge of this rare chromosome abnormality.

Matched MeSH terms: Chromosome Disorders/diagnosis; Chromosome Disorders/genetics

Fulltext A rare case of ambiguous genitalia

Ng SF, Boo NY, Wu LL, Shuib S

Singapore Med J, 2007 Sep;48(9):858-61.

PMID: 17728969

Genes on the Y chromosome are essential for normal sex determination and sex differentiation of male genitalia. However, genes on the X chromosome and other autosomes have been shown to be anti-testes and have a detrimental effect on this process. Addition of X chromosomes to the 46,XY karyotype results in seminiferous tubules dysgenesis, hypogonadism and malformed genitalia. We report a term male newborn with 49,XXXXY syndrome presenting with ambiguous genitalia, multiple extra-gonadal anomalies, facial dysmorphism, and radioulnar synostosis.

Matched MeSH terms: Sex Chromosome Disorders/genetics*; Sex Chromosome Disorders/pathology*

Duplication 17p11.2 (Potocki-Lupski Syndrome) in a child with developmental delay

Shuib S, Saaid NN, Zakaria Z, Ismail J, Abdul Latiff Z

Malays J Pathol, 2017 Apr;39(1):77-81.

PMID: 28413209 MyJurnal

Potocki-Lupski syndrome (PTLS), also known as duplication 17p11.2 syndrome, trisomy 17p11.2 or dup(17)(p11.2p11.2) syndrome, is a developmental disorder and a rare contiguous gene syndrome affecting 1 in 20,000 live births. Among the key features of such patients are autism spectrum disorder, learning disabilities, developmental delay, attention-deficit disorder, infantile hypotonia and cardiovascular abnormalities. Previous studies using microarray identified variations in the size and extent of the duplicated region of chromosome 17p11.2. However, there are a few genes which are considered as candidates for PTLS which include RAI1, SREBF1, DRG2, LLGL1, SHMT1 and ZFP179. In this report, we investigated a case of a 3-year-old girl who has developmental delay. Her chromosome analysis showed a normal karyotype (46,XX). Analysis using array CGH (4X44 K, Agilent USA) identified an ~4.2 Mb de novo duplication in chromosome 17p11.2. The result was confirmed by fluorescence in situ hybridization (FISH) using probes in the critical PTLS region. This report demonstrates the importance of microarray and FISH in the diagnosis of PTLS.

Matched MeSH terms: Chromosome Disorders/diagnosis*; Chromosome Disorders/genetics

Fulltext Down syndrome: multimodality imaging of associated congenital anomalies and acquired diseases

Tan AP

Med J Malaysia, 2013 Dec;68(6):482-9.

PMID: 24632922

Down syndrome (Trisomy 21) is the most common chromosomal abnormality among liveborn infants. It is the most frequent form of intellectual disability caused by a microscopically demonstrable chromosomal aberration. Management requires a multidisciplinary approach to the ongoing evaluation and monitoring for associated congenital anomalies and acquired disorders.Trisomy 21 is characterized by a variety of dysmorphic features, congenital anomalies and associated medical conditions. Knowledge of these associated conditions are important for clinicians involved in the management of these patients. Appropriate radiologic imaging with prompt, accurate interpretation plays an important role in the diagnosis and management of these diseases. The primary goal of this pictorial review is to unravel the radiological findings of these associated conditions.

Matched MeSH terms: Chromosome Disorders

Fulltext Cytogenetic study of Malaysian neonates with congenital abnormalities in Maternity Hospital Kuala Lumpur

Norlasiah IS, Clyde MM, Boo NY

Med J Malaysia, 1995 Mar;50(1):52-8.

PMID: 7752977

During the period 1 January 1990-31 December 1990, 68 neonates with congenital abnormalities were successfully analysed for chromosome abnormalities in order to determine the contribution of chromosome aberrations to the aetiology of congenital abnormalities. The neonates were karyotyped employing the G-banding technique. Twenty-nine babies showed abnormal chromosome karyotypes. Twenty-six were observed to have classic trisomy syndromes; ie. trisomy 21 (32.3%), trisomy 18 (3.0%), and trisomy 13 (3.0%). The mean maternal age of the mothers with babies having normal karyotype was lower than the mean maternal age of the mothers having babies with abnormal karyotypes. From this study the incidence of congenital abnormalities due to chromosomal abnormalities is found to be 1:838 livebirths. Frequency of newborns having abnormal chromosomes is 0.14% for Malays, 0.12% for Chinese and 0.06% for Indians.

Matched MeSH terms: Chromosome Disorders

Fulltext Chromosome abnormalities in leukemia: a review

Chin YM, Hassan K

Med J Malaysia, 1984 Jun;39(2):103-11.

PMID: 6595495

The common chromosome abnormalities that are encountered in the various types of leukemia are discussed here. Chromosome abnormalities in leukemia are non-random and certain chromosomal changes are now becoming recognised as being rather specific for certain leukemia types.

Matched MeSH terms: Chromosome Disorders

Human chromosomal studies in Kuala Lumpur

Yip MY, Yong HS, Dhaliwal SS

Med J Malaysia, 1978 Jun;32(4):316-20.

PMID: 732631

Matched MeSH terms: Chromosome Disorders

Fulltext Down syndrome and Patau syndrome in the same sibship: random or not?

Foong Eva, Hasliani Hassan, Azizah Othman, Ilunihayati Ibrahim, Nazihah Mohd Yunus, Siti Mariam Ismail, et al.

Malaysian Journal of Paediatrics and Child Health, 2017;23(2):0-0.

MyJurnal

Objectives: Chromosomal abnormalities especially aneuploidies are the most common etiology for pregnancy loss. Trisomy 13, trisomy 18 and trisomy 21 are the most common chromosome autosomal aneuploidies with trisomy 21 (Down syndrome) being the most common chromosomal abnormality among liveborn infants. In previous reports, we noted that the recurrence of these aneuploidies in some families may not occur by chance alone.

Methods: Extraction of relevant data from review of medical case notes of a young couple with two offspring with Down syndrome (DS) and Patau syndrome.

Results: A family history of DS is a predisposing factor for both DS and other types of aneuploidy. Certain instances of non-disjunction error are not random.

Conclusion: As the maternal age was not advanced in both pregnancies, there is a possibility that the recurrent aneuploidy in this family may not be accounted by chance alone. The risk of having subsequent affected pregnancy cannot be ignored in this family and prenatal diagnosis is strongly recommended in the subsequent pregnancy.

Matched MeSH terms: Chromosome Disorders

Fulltext Chromosomal abnormalities and reproductive outcome in Malaysian couples with miscarriages

Pal S, Ma SO, Norhasimah M, Suhaida MA, Siti Mariam I, Ankathil R, et al.

Singapore Med J, 2009 Oct;50(10):1008-12.

PMID: 19907893

This study was done to determine the prevalence of chromosomal abnormalities and the subsequent reproductive outcome in couples who had two or more miscarriages.

Matched MeSH terms: Chromosome Disorders/genetics

Fulltext Interstitial deletion of the distal long arm of chromosome 4, del (4)(q33-q35), in association with paternal balanced translocation

Mdzin R, Ko C, Abdul Latif Z, Zakaria Z

Singapore Med J, 2008 Nov;49(11):e336-9.

PMID: 19037546

Interstitial deletions of the long arm of chromosome 4 are rare. The deletions may occur at the proximal or the distal portions of the chromosome and different breakpoints may be involved. We report an interstitial deletion of 4q: 46XY der 4 (q28;q35) in a six-year-old boy with dysmorphic features associated with moderate mental retardation. Parental chromosomal analysis showed a balanced paternal translocation.

Matched MeSH terms: Chromosome Disorders/genetics

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: Chromosome Disorders*

Fulltext Hereditary ovalocytosis in Malays

George E, Mohandas N, Duraisamy G, Adeeb N, Zainuddin ZA, Teng MS, et al.

Med J Malaysia, 1988 Dec;43(4):327-31.

PMID: 3241598

Matched MeSH terms: Chromosome Disorders

Fulltext Complex chromosomal rearrangement der(5)ins(5;3)(q31;q25q29), t(3;12)(q24;p12.2) in a dysmorphic child, - a case report

Aziati Azwari Annuar, Nik Mohd Zulfikri Mat Zin, Siti Mariam Ismail, Nurul Alia Mohd Nawi, Nazihah Mohd Yunus, Sarina Sulong, et al.

Journal of Biomedical and Clinical Sciences, 2017;2(202):3-5.

MyJurnal

Complex chromosome rearrangements (CCRs) are structural aberrations or rearrangements involving three or more cytogenetics breakpoints on two or more chromosomes [1]. Balanced and unbalanced are known to have significant risk of mental retardation and phenotypic anomalies. CCRs are also associated with infertility in males and recurrent abortion in females. Here we report one case of apparently balanced CCR involving three chromosomes 3, 5 and 12 in a child with abnormal features. G banding and FISH were performed to clarify the nature of this complex abnormality.

Matched MeSH terms: Chromosome Disorders

A mother with variant Turner syndrome and two daughters with trisomy X: a case report

Ramachandram S, Keng WT, Ariffin R, Ganesan V

J Genet, 2013;92(2):313-6.

PMID: 23970090

Matched MeSH terms: Sex Chromosome Disorders of Sex Development/genetics*

Early transition from insulin to sulfonylureas in neonatal diabetes and follow-up: Experience from China

Li X, Xu A, Sheng H, Ting TH, Mao X, Huang X, et al.

Pediatr Diabetes, 2018 03;19(2):251-258.

PMID: 28791793 DOI: 10.1111/pedi.12560

BACKGROUND: Sulfonylurea therapy can improve glycemic control and ameliorate neurodevelopmental outcomes in patients suffering from neonatal diabetes mellitus (NDM) with KCNJ11 or ABCC8 mutations. As genetic testing results are often delayed, it remains controversial whether sulfonylurea treatment should be attempted immediately at diagnosis or doctors should await genetic confirmation.

OBJECTIVE: This study aimed to investigate the effectiveness and safety of sulfonylurea therapy in Chinese NDM patients during infancy before genetic testing results were available.

METHODS: The medical records of NDM patients with their follow-up details were reviewed and molecular genetic analysis was performed. Sulfonylurea transfer regimens were applied in patients diagnosed after May 2010, and glycemic status and side effects were evaluated in each patient.

RESULTS: There were 23 NDM patients from 22 unrelated families, 10 had KCNJ11 mutations, 3 harbored ABCC8 mutations, 1 had INS mutations, 4 had chromosome 6q24 abnormalities, 1 had a deletion at chromosome 1p36.23p36.12, and 4 had no genetic abnormality identified. Sixteen NDM infants were treated with glyburide at an average age of 49 days (range 14-120 days) before genetic confirmation. A total of 11 of 16 (69%) were able to successfully switch to glyburide with a more stable glucose profile. The responsive glyburide dose was 0.51 ± 0.16 mg/kg/d (0.3-0.8 mg/kg/d), while the maintenance dose was 0.30 ± 0.07 mg/kg/d (0.2-0.4 mg/kg/d). No serious adverse events were reported.

CONCLUSIONS: Molecular genetic diagnosis is recommended in all patients with NDM. However, if genetic testing results are delayed, sulfonylurea therapy should be considered before such results are received, even in infants with newly diagnosed NDM.

Matched MeSH terms: Chromosome Disorders/drug therapy; Chromosome Disorders/genetics

Fulltext Common variable immunodeficiency (hypogammaglobulinemia) with an autosomal recessive pattern of inheritance

Lokman MN, George R, Sukumaran S, Nasuruddin BA

Med J Malaysia, 1988 Sep;43(3):237-42.

PMID: 3241582

Matched MeSH terms: Chromosome Disorders

Fulltext Genetic diseases and antenatal diagnosis

Wong HB

Med J Malaysia, 1985 Sep;40(3):153-64.

PMID: 3916209

The different methods of prenatal diagnosis are discussed with special reference to ultrasound scan, amniocentesis for cell culture with processing for chromosome study, biochemical analysis and DNA recombination analysis. Chorionic villi aspiration and fetoscopy are new methods which will enhance considerably the methods for prenatal diagnosis. With regard to chromosome study of amniotic cells, experience with 623 cases is reviewed. 2.7% demonstrated chromosome anomalies and of these Downs anomaly was the commonest. A large proportion of cases requesting for amniocentesis are Caucasians who represent only 2% of the population in Singapore, but 25% of the 440 requests were from Caucasions. The various problems associated with the different methods for prenatal deafness are discussed.

Matched MeSH terms: Chromosome Disorders

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: Chromosome Disorders

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