Chromosome 21 CORINNE WONG*, HAIG H

Total Page:16

File Type:pdf, Size:1020Kb

Chromosome 21 CORINNE WONG*, HAIG H Proc. Nati. Acad. Sci. USA Vol. 86, pp. 1914-1918, March 1989 Genetics Molecular mechanism in the formation of a human ring chromosome 21 CORINNE WONG*, HAIG H. KAZAZIAN, JR.*, GAIL STETTENt, WILLIAM C. EARNSHAWt, MARGARET L. VAN KEUREN§¶, AND STYLIANOS E. ANTONARAKIS*II *Program in Human Genetics, Genetics Unit, Department of Pediatrics, tDepartment of Gynecology and Obstetrics, and tDepartment of Anatomy and Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205; and §Eleanor Roosevelt Institute for Cancer Research, 4200 East Ninth Avenue, Denver, CO 80206 Communicated by Victor A. McKusick, October 5, 1988 ABSTRACT We have characterized the structural re- D21K9 of locus D21S13, were used (18). The superoxide arrangements of a chromosome 21 that led to the de novo dismutase 1 probe (SOD-1) (20) and 0-amyloid probe (APP) formation of a human ring chromosome 21 [r(21)]. Molecular (21) were also employed. The DNA fragment CW21A is a cloning and chromosomal localization of the DNA regions 650-nucleotide (nt) Pvu II-Sph I fragment, cloned in flanking the ring junction provide evidence for a long arm to M13mp9, that spans the break point. The DNA fragment long arm fusion in formation of the r(21). In addition, the CW21B of locus D21S111 is a 530-nt HindIII-Sph I fragment centromere and proximal long arm region of a maternal located on the 5' side of the break point, cloned in M13mp9 chromosome 21 are duplicated in the r(21). Therefore, the and pGEM-4. mechanism in formation ofthe r(21) was complex involving two Somatic Cell Hybrids. A somatic cell hybrid (R2-10) con- sequential chromosomal rearrangements. (i) Duplication ofthe taining r(21) as the only detectable human chromosome was centromere and long arm of one maternal chromosome 21 made (19). The R2-10 line was also back selected for loss of occurred forming a rearranged intermediate. (ii) Chromo- the r(21) (cell line R2-1OW-S5) by growth in nonselective somal breaks in both the proximal and telomeric long arm (purine supplemented) medium, followed by selective me- regions on opposite arms of this rearranged chromosome dium with the addition of bromodeoxyuridine and light (22). occurred with subsequent reunion producing the r(21). For mapping, a panel of somatic cell hybrids, 72532X-6, 153E7bx, and 2FuR1 (23), with characterized rearrangements Ring chromosomes in humans represent a class of aberrant of human chromosome 21 was used (19). chromosomes observed frequently in congenital anomalies Cloning the Chromosomal Break Points. DNA from the and occasionally with normal phenotypes (1). Most ring patient's blood lymphocytes was digested with EcoRI and a chromosomes arise de novo, yet occasional familial trans- size-selected library (7-9 kb) was made in Agtwes B. About mission has been reported (2-5). The frequency of ring 300,000 recombinant phage were screened (24) with chromosomes is 1 in 25,000 recognized conceptions (6), and pPW231C and a single clone, A21BP (Fig. 1B), was purified. all human chromosomes have been observed as rings. Almost DNA from the region on the 3' side of the break point was 50% of ring autosomes are derived from the acrocentric cloned (A2lpq) by using probe CW21A from a flow-sorted, chromosomes (7). The proposed mechanism of ring forma- HindIII-digested chromosome 21 library in Charon 21A (ID tion, breakage of both short and long arms of a chromosome code, LL21NS02; American Type Culture Collection num- with subsequent end to end fusion (8), remains unproven. In ber, 57713). several reports of acrocentric ring chromosomes, a Robert- Immunofluorescence Studies. For quantification of DNA, sonian translocation produced by short arm fusion has been photographic negatives of 4',6-diamidino-2-phenylindole observed in the patient, a parent, or a sibling (9-16). In each (DAPI)-stained (25) images were scanned using a Loats case, one or both of the chromosomes involved in the (Westminster, MD) video densitometer equipped with a two- translocation were present in the ring, suggesting that ring dimensional gel-scanning software package. Indirect immu- formation was related to or derived from the translocation. In nofluorescence was performed on mitotic spreads (26). Chro- this study, we characterize a ring chromosome 21 [r(21)] and mosomes were first stained with DAPI and then with a provide molecular evidence** for the formation of a rear- monoclonal anti-centromere antibody prepared against the ranged chromosome 21 with a duplicated centromere and cloned 80-kDa human autoantigen CENP-B (27). Bound long arm that preceded ring formation. antibody was detected with a second antibody coupled to streptavidin linked to Texas red dye. MATERIALS AND METHODS Sources of DNA. DNA was isolated from cultured amnio- RESULTS cytes and fibroblasts and peripheral blood from the proband Cytogenetic Characterization and Origin of r(21). r(21) was with the r(21) and his parents (17). Fibroblast and lympho- observed in 90% of the cultured amniocytes, fibroblasts, and blastoid cell lines were established from the proband (GM lymphocytes (28, 29); the remaining 10% of the cells were 6137 and GM 6779) and a lymphoblastoid line was established monosomic for chromosome 21. Break points were located at from his mother (GM 8779) and stored in the Coriell Institute band 21q22.3 and in the pericentromeric region. r(21)s were for Medical Research (Camden, NJ). variable in size, the majority (84%) being slightly larger than DNA fragment pPW231C of locus D21S3 is a 2.1-kilobase (kb) EcoRI fragment cloned in pBR328 (18, 19). Additional Abbreviations: r(21), ring chromosome 21; nt, nucleotide(s); DAPI, chromosome 21-specific probes, pPW228C of locus D21S1, 4',6-diamidine-2-phenylindole; MAR, matrix-association region; pPW236B of locus D21S11, pPW245D of locus D21S8, and LINE, long interspersed repetitive element. VPresent address: Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI 48109. The publication costs of this article were defrayed in part by page charge I1To whom reprint requests should be addressed. payment. This article must therefore be hereby marked "advertisement" **The sequence reported in this paper is being deposited in the in accordance with 18 U.S.C. §1734 solely to indicate this fact. EMBL/GenBank data base (accession no. J04504). 1914 Downloaded by guest on September 25, 2021 Genetics: Wong et al. Proc. Natl. Acad. Sci. USA 86 (1989) 1915 of the child and his parents was analyzed. Probe pPW231C 17 nt reat A Brealokit detected new DNA fragments in the child's DNA that were t MAR homolg - UNE pat absent in the DNA of the parents with several restriction I TOPO II homology enzymes. Analysis with EcoRI, for example, showed a normal 2.1-kb fragment in all family members and a new 7.5-kb fragment in DNA isolated from the child's blood and fibroblasts, indicating that a chromosomal break occurred X21lpq i ,szc (D2lSll1) within the 2.1-kb EcoRI fragment pPW231C (29). 1m l ,I1 A. 5' 1.6 . P 3' The 7.5-kb EcoRI junction fragment was cloned (A21BP) proximal long arm from blood lymphocytes of the child and the corresponding CW21 B normal region of DNA brought into juxtaposition to pPW231C was also cloned as a 3.0-kb HindIII fragment from II a chromosome 21 library. This latterfragment is A2lpq ofFig. 72 1A and has been designated locus D21S111. The restriction X21BP I maps of the cloned 1 indicated that 5'. 3 fragments (Fig. A-C) 5. g,,,,"n,,,,,,,JJ>,,,z,,,,,,,,,,,,XW,,,%XiR,2222i~yMM0X~s 3 breakage occurred in A21pq and pPW231C and that fusion tol Z, f junction fragment was within A21BP. DNA fragments on both sides of the i CW21 A junction were mapped to chromosome 21 by using somatic cell hybrids containing chromosome 21 (72532X-6) as the only human chromosome, thereby excluding involvement of A , Tr CT chromosomes other than 21 in ring formation. D21S3 Nucleotide of C. 5' I Sequence Comparisons pPW231C, A21BP, Ito distal long arm and A21pq. DNA sequences of the 2.1-kb pPW231C frag- pPW23I C ment, the 2.7-kb from the 5' end of A21BP, and the 1.5-kb from the 5' half of A21pq were determined (Fig. 3). The FIG. 1 . Identification and cloning the ringjunction fragment and sequences of A21BP and pPW231C 5' to nt 623 are identical surrounding normal DNA. The junction fragment A21BP (B) as well except for a nt substitution at position 574, a probable neutral as 3.5 kb from the surrounding region A21pq (A) were cloned. The sequence polymorphism. No differences were noted between DNA fragment pPW231C is also shown (C). Restriction maps ofthe A21BP and A21pq in the 1.5-kb region sequenced 3' to the three cloned regions are aligned by the vertical dotted line repre- senting the reunion site. The 5' and 3' orientations ofthe clones were junction point. arbitrarily designated. Regions of identity are indicated by the At the ring junction, 9 nt, CATTCACCA, of unknown hatched or open bars. Probes CW21B and CW21A are underlined in origin were inserted (Fig. 3). Both break points occurred A and B, respectively. Symbols identify DNA sequence determinants within single-copy sequences; pPW231C is single-copy and shown in Fig. 3. the first 1 kb at the 5' end of A21pq is also free of repetitive sequences. Two single-copy probes flanking the ringjunction the corresponding homologue. Dicentric rings approximately (CW21B, just 5' to the break point, and CW21A, on the 3' twice the size of the normal chromosome 21 were 12% ofthe side) represent contiguous fragments in normal DNA, yet r(21), and the remaining 4% of the rings appeared equivalent they were derived from two separate clones, A21pq and in size to the corresponding homologue.
Recommended publications
  • Ring 21 FTNW
    Ring 21 rarechromo.org Sources Ring 21 The information Ring 21 is a rare genetic condition caused by having a in this leaflet ring-shaped chromosome. comes from the Almost half of the people with ring 21 chromosomes medical literature described in the medical literature are healthy and and from develop normally. Their unusual chromosomes are Unique’s discovered by chance, during tests for infertility or after members with repeated miscarriages or after having an affected baby. Ring 21 In other people the ring 21 chromosome affects (referenced U), development and learning and can also cause medical who were problems. In most of these people these effects are surveyed in slight but in some people they can be severe. The 2004. Unique is effects can even vary between different members of the very grateful to same family. The reason for these differences is not yet the families who fully understood. took part in the survey. What is a chromosome? The human body is made up of cells. Inside most cells is References a nucleus where genetic information is stored in genes which are grouped along chromosomes. Chromosomes The text contains are large enough to be studied under a microscope and references to come in different sizes, each with a short (p) and a long articles published (q) arm. They are numbered from largest to smallest in the medical according to their size, from number 1 to number 22, in press. The first- addition to the sex chromosomes, X and Y. A normal, named author healthy cell in the body has 46 chromosomes, 23 from and publication the mother and 23 from the father, including one date are given to chromosome 21 from each parent.
    [Show full text]
  • Epigenetic Control of Mammalian Centromere Protein Binding: Does DNA Methylation Have a Role?
    Journal of Cell Science 109, 2199-2206 (1996) 2199 Printed in Great Britain © The Company of Biologists Limited 1996 JCS3386 Epigenetic control of mammalian centromere protein binding: does DNA methylation have a role? Arthur R. Mitchell*, Peter Jeppesen, Linda Nicol†, Harris Morrison and David Kipling MRC Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK *Author for correspondence (internet [email protected]) †Present address: MRC Reproductive Biology Unit, Edinburgh, UK SUMMARY Chromosome 1 of the inbred mouse strain DBA/2 has a block of minor satellite DNA sequences on chromosome 1. polymorphism associated with the minor satellite DNA at The binding of the CENP-E protein does not appear to be its centromere. The more terminal block of satellite DNA affected by demethylation of the minor satellite sequences. sequences on this chromosome acts as the centromere as We present a model to explain these observations. This shown by the binding of CREST ACA serum, anti-CENP- model may also indicate the mechanism by which the B and anti-CENP-E polyclonal sera. Demethylation of the CENP-B protein recognises specific sites within the arrays minor satellite DNA sequences accomplished by growing of minor satellite DNA on mouse chromosomes. cells in the presence of the drug 5-aza-2′-deoxycytidine results in a redistribution of the CENP-B protein. This protein now binds to an enlarged area on the more terminal Key words: Centromere satellite DNA, Demethylation, Centromere block and in addition it now binds to the more internal antibody INTRODUCTION A common feature of many mammalian pericentromeric domains is that they contain families of repetitive DNA The centromere of mammalian chromosomes is recognised at sequences (Singer, 1982).
    [Show full text]
  • The 50Th Anniversary of the Discovery of Trisomy 21: the Past, Present, and Future of Research and Treatment of Down Syndrome
    REVIEW The 50th anniversary of the discovery of trisomy 21: The past, present, and future of research and treatment of Down syndrome Andre´Me´garbane´, MD, PhD1,2, Aime´ Ravel, MD1, Clotilde Mircher, MD1, Franck Sturtz, MD, PhD1,3, Yann Grattau, MD1, Marie-Odile Rethore´, MD1, Jean-Maurice Delabar, PhD4, and William C. Mobley, MD, PhD5 Abstract: Trisomy 21 or Down syndrome is a chromosomal disorder HISTORICAL REVIEW resulting from the presence of all or part of an extra Chromosome 21. Clinical description It is a common birth defect, the most frequent and most recognizable By examining artifacts from the Tumaco-La Tolita culture, form of mental retardation, appearing in about 1 of every 700 newborns. which existed on the border between current Colombia and Although the syndrome had been described thousands of years before, Ecuador approximately 2500 years ago, Bernal and Briceno2 it was named after John Langdon Down who reported its clinical suspected that certain figurines depicted individuals with Tri- description in 1866. The suspected association of Down syndrome with somy 21, making these potteries the earliest evidence for the a chromosomal abnormality was confirmed by Lejeune et al. in 1959. existence of the syndrome. Martinez-Frias3 identified the syn- Fifty years after the discovery of the origin of Down syndrome, the term drome in a terra-cotta head from the Tolteca culture of Mexico “mongolism” is still inappropriately used; persons with Down syn- in 500 patients with AD in which the facial features of Trisomy drome are still institutionalized. Health problems associated with that 21 are clearly displayed.
    [Show full text]
  • Biol 1020: Chromosomal Genetics
    Ch. 15: Chromosomal Abnormalities Abnormalities in Chromosomal Number Abnormalities in Chromosomal Structure: Rearrangements Fragile Sites . • Define: – nondisjunction – polyploidy – aneupoidy – trisomy – monosomy . Abnormalities in chromosomal number How does it happen? . Abnormalities in chromosomal number nondisjunction - mistake in cell division where chromosomes do not separate properly in anaphase usually in meiosis, although in mitosis occasionally in meiosis, can occur in anaphase I or II . Abnormalities in chromosomal number polyploidy – complete extra sets (3n, etc.) – fatal in humans, most animals aneuploidy – missing one copy or have an extra copy of a single chromosome three copies of a chromosome in your somatic cells: trisomy one copy of a chromosome in your somatic cells: monosomy most trisomies and monosomies are lethal well before birth in humans; exceptions will be covered . Abnormalities in chromosomal number generally, in humans autosomal aneuploids tend to be spontaneously aborted over 1/5 of human pregnancies are lost spontaneously after implantation (probably closer to 1/3) chromosomal abnormalities are the leading known cause of pregnancy loss data indicate that minimum 10-15% of conceptions have a chromosomal abnormality at least 95% of these conceptions spontaneously abort (often without being noticed) . • Define: – nondisjunction – polyploidy – aneupoidy – trisomy – monosomy . • Describe each of the aneuploidies that can be found in an appreciable number of human adults (chromosomal abnormality, common name of the syndrome if it has one, phenotypes) . aneuploidy in human sex chromosomes X_ female (Turner syndrome) short stature; sterile (immature sex organs); often reduced mental abilities about 1 in 2500 human female births XXY male (Klinefelter syndrome) often not detected until puberty, when female body characteristics develop sterile; sometimes reduced mental abilities; testosterone shots can be used as a partial treatment; about 1 in 500 human male births .
    [Show full text]
  • Dr. Fern Tsien, Dept. of Genetics, LSUHSC, NO, LA Down Syndrome
    COMMON TYPES OF CHROMOSOME ABNORMALITIES Dr. Fern Tsien, Dept. of Genetics, LSUHSC, NO, LA A. Trisomy: instead of having the normal two copies of each chromosome, an individual has three of a particular chromosome. Which chromosome is trisomic determines the type and severity of the disorder. Down syndrome or Trisomy 21, is the most common trisomy, occurring in 1 per 800 births (about 3,400) a year in the United States. It is one of the most common genetic birth defects. According to the National Down Syndrome Society, there are more than 400,000 individuals with Down syndrome in the United States. Patients with Down syndrome have three copies of their 21 chromosomes instead of the normal two. The major clinical features of Down syndrome patients include low muscle tone, small stature, an upward slant to the eyes, a single deep crease across the center of the palm, mental retardation, and physical abnormalities, including heart and intestinal defects, and increased risk of leukemia. Every person with Down syndrome is a unique individual and may possess these characteristics to different degrees. Down syndrome patients Karyotype of a male patient with trisomy 21 What are the causes of Down syndrome? • 95% of all Down syndrome patients have a trisomy due to nondisjunction before fertilization • 1-2% have a mosaic karyotype due to nondisjunction after fertilization • 3-4% are due to a translocation 1. Nondisjunction refers to the failure of chromosomes to separate during cell division in the formation of the egg, sperm, or the fetus, causing an abnormal number of chromosomes. As a result, the baby may have an extra chromosome (trisomy).
    [Show full text]
  • Cytogenetics, Chromosomal Genetics
    Cytogenetics Chromosomal Genetics Sophie Dahoun Service de Génétique Médicale, HUG Geneva, Switzerland [email protected] Training Course in Sexual and Reproductive Health Research Geneva 2010 Cytogenetics is the branch of genetics that correlates the structure, number, and behaviour of chromosomes with heredity and diseases Conventional cytogenetics Molecular cytogenetics Molecular Biology I. Karyotype Definition Chromosomal Banding Resolution limits Nomenclature The metaphasic chromosome telomeres p arm q arm G-banded Human Karyotype Tjio & Levan 1956 Karyotype: The characterization of the chromosomal complement of an individual's cell, including number, form, and size of the chromosomes. A photomicrograph of chromosomes arranged according to a standard classification. A chromosome banding pattern is comprised of alternating light and dark stripes, or bands, that appear along its length after being stained with a dye. A unique banding pattern is used to identify each chromosome Chromosome banding techniques and staining Giemsa has become the most commonly used stain in cytogenetic analysis. Most G-banding techniques require pretreating the chromosomes with a proteolytic enzyme such as trypsin. G- banding preferentially stains the regions of DNA that are rich in adenine and thymine. R-banding involves pretreating cells with a hot salt solution that denatures DNA that is rich in adenine and thymine. The chromosomes are then stained with Giemsa. C-banding stains areas of heterochromatin, which are tightly packed and contain
    [Show full text]
  • Down's Syndrome Phenotype and Autosomal Gene Inactivation in a Child with Presumed
    J Med Genet: first published as 10.1136/jmg.19.2.144 on 1 April 1982. Downloaded from 144 Case reports Down's syndrome phenotype and Case report autosomal gene inactivation in a The proband, a 3 2-year-old white female, was referred for evaluation of developmental delay and child with presumed (X;21) de novo dysmorphic features. She was the 1790 g,. 39 week translocation gestation product of a gravida 1, para 0, 15-year-old female. The pregnancy was complicated with SUMMARY A 32-year-old female with clinical recurrent urinary tract infections. The mother used features of Down's syndrome was found to have alcohol and tobacco in small quantities during the extra chromosome material on the long arm of pregnancy. The labour lasted ten hours and the one of the X chromosomes, 46,XXq+. The delivery was vaginal with vertex presentation. The parental karyotypes were normal. In the light baby breathed and cried spontaneously. Her of the clinical features of the proband and the immediate neonatal course was uneventful, but her subsequent weight gain was poor. She had several banding characteristics of the extra chromosome admissions to hospital for repeated diarrhoea, otitis material, the patient was thought to have a de media, and pneumonia. She had two 'febrile' seizures novo (X;21) translocation. The results of late for which she was placed on phenobarbital. Her replication studies with BUdR and enzyme development was markedly delayed. She smiled at superoxide dismutase (SOD) assays in the 4 months, turned over at 7 months, walked at 18 proband suggest that: (1) the presumed (X;21) months, and was not yet toilet trained.
    [Show full text]
  • Comparative Mapping of DNA Markers from the Familial Alzheimer Mouse Chromosomes 16 and 17
    Proc. Natl. Acad. Sci. USA Vol. 85, pp. 6032-6036, August 1988 Genetics Comparative mapping of DNA markers from the familial Alzheimer disease and Down syndrome regions of human chromosome 21 to mouse chromosomes 16 and 17 (restriction fragment length polymorphism/genetic linkage analysis/recombinant inbred strains/interspecific backcross) SHIRLEY V. CHENG*, JOSEPH H. NADEAUt, RUDOLPH E. TANZI*, PAUL C. WATKINSt, JAYASHREE JAGADESH*, BENJAMIN A. TAYLORt, JONATHAN L. HAINES*, NICOLETTA SACCHI§, AND JAMES F. GUSELLA* *Neurogenetics Laboratoiy, Massachusetts General Hospital and Department of Genetics, Harvard Medical School, Boston, MA 02114; tThe Jackson Laboratory, Bar Harbor, ME 04609; tIntegrated Genetics, Inc., 31 New York Avenue, Framingham, MA 01701; and §Laboratory of Molecular Oncology, National Cancer Institute, Frederick, MD 21701 Communicated by Elizabeth S. Russell, April 18, 1988 ABSTRACT Mouse trisomy 16 has been proposed as an mouse genome, mouse trisomy 16 has been used as an animal animal model of Down syndrome (DS), since this chromosome model of DS (9, 10). contains homologues of several loci from the q22 band of Interest in human chromosome 21 has increased with the human chromosome 21. The recent mapping of the defect recent localizations of the defect causing familial Alzheimer causing familial Alzheimer disease (FAD) and the locus encod- disease (FAD) and the gene (APP) encoding the precursor for ing the Alzheiner amyloid (3 precursor protein (APP) to human amyloid ,8 protein to the proximal half of 21q (11, 12). FAD chromosome 21 has prompted a more detailed examination of is the autosomal dominantly inherited form of the common the extent ofconservation ofthis linkage group between the two late-onset neurodegenerative disorder that results in the species.
    [Show full text]
  • 43 Case Report. Down Syndrome Caused by 21
    DOI: http://doi.org/10.4038/sljm.v27i2.85 Sri Lanka Journal of Medicine Vol. 27 No.2, 2018 CASE REPORT. DOWN SYNDROME CAUSED BY 21; 21 ROBERTSONIAN TRANSLOCATION D.U.A. Kollurage1and S.T. Kudagammana 1,2 1Professorial Paediatric Unit, Teaching Hospital, Peradeniya 2Department of Paediatrics, Faculty of Medicine, University of Peradeniya Corresponding Author:Dr. S.T.Kudagammana Email [email protected] https://orcid.org/0000-0002-5813-5907 Abstract Down syndrome, also known as Trisomy-21, is the most common viable aneuploidy in humans. It was first described as a syndrome by John Langdon Down in 1866 and later Jerome Lejeune and Patricia Jacobs explained the association between the third copy of the 21st chromosome and syndromic manifestations. The usual incidence of Down syndrome is 1 in 700 live births. Of all cases of Down syndrome, 95% are caused by non-disjunction. Robertsonian translocation of 21; 21 is extremely rare. To the best of our knowledge, we are reporting the first case of 21;21 translocation causing Down syndrome from Sri Lanka. Key words: Trisomy 21, Robertsonian translocation, de novo mutation, mosaicism Background She was the first-bornbaby to non- consanguineous healthy parents. The The genetic basis of Down syndrome mother was 34 years and the father 36 includes chromosomal non-disjunction, years in age. The pregnancy was genetic mosaicism and translocation/ ring uneventful and the baby was delivered by chromosomes or isochromosomes. Down normal vaginal delivery at 37 weeks of syndrome due to 21; 21 translocation is gestation, with a birth weight of 2.56 kg. extremely rare.
    [Show full text]
  • Modifier Genes in Microcephaly: a Report on WDR62, CEP63, RAD50
    G C A T T A C G G C A T genes Article Modifier Genes in Microcephaly: A Report on WDR62, CEP63, RAD50 and PCNT Variants Exacerbating Disease Caused by Biallelic Mutations of ASPM and CENPJ Ehtisham Ul Haq Makhdoom 1,2,3,†, Syeda Seema Waseem 1,4,†, Maria Iqbal 1,2,4, Uzma Abdullah 5 , Ghulam Hussain 3, Maria Asif 1,4, Birgit Budde 1 , Wolfgang Höhne 1, Sigrid Tinschert 6, Saadia Maryam Saadi 2 , Hammad Yousaf 2, Zafar Ali 7, Ambrin Fatima 8, Emrah Kaygusuz 9 , Ayaz Khan 2 , Muhammad Jameel 2, Sheraz Khan 2 , Muhammad Tariq 2 , Iram Anjum 10 , Janine Altmüller 1, Holger Thiele 1, Stefan Höning 4, Shahid Mahmood Baig 2,8,11, Peter Nürnberg 1,12 and Muhammad Sajid Hussain 1,4,12,* 1 Cologne Center for Genomics (CCG), Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; [email protected] (E.U.H.M.); [email protected] (S.S.W.); [email protected] (M.I.); [email protected] (M.A.); [email protected] (B.B.); [email protected] (W.H.); [email protected] (J.A.); [email protected] (H.T.); [email protected] (P.N.) 2 Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad 38000, Pakistan; [email protected] (S.M.S.); [email protected] (H.Y.); [email protected] (A.K.); [email protected] (M.J.); [email protected] (S.K.); [email protected] (M.T.); [email protected] (S.M.B.) 3 Citation: Makhdoom, E.U.H.; Neurochemicalbiology and Genetics Laboratory (NGL), Department of Physiology, Faculty of Life Sciences, Waseem, S.S.; Iqbal, M.; Abdullah, U.; Government College University, Faisalabad 38000, Pakistan; [email protected] 4 Hussain, G.; Asif, M.; Budde, B.; Institute of Biochemistry I, Medical Faculty, University of Cologne, 50931 Cologne, Germany; [email protected] Höhne, W.; Tinschert, S.; Saadi, 5 University Institute of Biochemistry and Biotechnology (UIBB), PMAS-Arid Agriculture University, S.M.; et al.
    [Show full text]
  • Chromosome Abnormalities
    Testing for Chromosome Abnormalities Department of Obstetrics and Gynecology Maternal-Fetal Medicine and Prenatal Genetics Congratulations on your pregnancy! While most babies are born healthy, approximately 3-5% will be affected with certain birth defects or genetic conditions. In all pregnancies, tests are offered that can tell if the pregnancy may be at high risk for a condition called a chromosome abnormality. Decisions about testing in pregnancy are personal. Some choose not to have any testing done. Others find the information from testing to be helpful. We have made this booklet to give some information on the tests available. We hope that having this information and discussing it with your OB/GYN provider will help you to decide whether this testing makes sense for you and your family. What are chromosomes? Our bodies are made of tiny cells. Chromosomes are the packages of genetic information (DNA) inside our Chromosome cells. They contain the instructions for our growth Cell and development. Usually, each person has a total of 46 chromosomes in each cell. The chromosomes come in pairs (23 pairs). Each parent contributes one chromosome to each pair. When a fetus (developing baby) has extra or missing chromosomes, it can lead to medical problems. An extra chromosome (three copies instead of two) is called a trisomy. A missing chromosome (one copy instead of two) is called a monosomy. This type of genetic condition doesn’t usually run in families. It can happen just by chance in any pregnancy. DNA What are the most common chromosomal abnormalities? The most common differences related to the number of chromosomes are: • Down syndrome: Down syndrome is also called trisomy 21.
    [Show full text]
  • Genetic Testing - What Is Trisomy 21, 18 and 13?
    9195 Grant Street, Suite 410 300 Exempla Circle, Suite 470 6363 West 120th Avenue, Suite 300 Thornton, CO 80229 Lafayette, CO 80026 Broomfield, CO 80020 Phone: 303-280-2229(BABY) 303-665-6016 303-460-7116 Fax: 303-280-0765 303-665-0121 303-460-8204 www.whg-pc.com Genetic Testing - What is Trisomy 21, 18 and 13? Genes are the part of the cell that contain the biological information that control the growth and development of cells. Genes, alone or in combination, determine many of the genetic traits that a person inherits, including risks of developing certain diseases or conditions. Genes are grouped into larger structures within the cells called chromosomes. The human body has 23 distinct chromosome pairs or copies. Trisomy 21, 18 or 13 means there are three copies of that particular chromosome instead of two. Down syndrome is a condition in which an extra copy of chromosome 21 causes’ delays in the way a child develops, both mentally and physically. Not everyone with Down syndrome is affected in the same way, and there is no way to determine before birth how a child may be affected. There are three different types of Down syndrome with the most common referred to as trisomy 21. The other two types are called Robertsonian translocation and Mosaicism and these occur in about 4-6% of babies born with Down syndrome. Down Syndrome affects about 1 in every 700 babies. The risk to have a child with Down syndrome does increase with the mother’s age, but mothers of all ages can have a child with Down syndrome and it can occur in people of all races.
    [Show full text]