FACULDADE DE MEDICINA DA UNIVERSIDADE DE COIMBRA 1

FACULDADE DE MEDICINA DA UNIVERSIDADE DE COIMBRA 1. º ANO MESTRADO INTEGRADO MEDICINA BIOLOGIA CELULAR E MOLECULAR II MOSAICISM MECHANISMS AND IMPACT ON THE DISEASE 13 TH MARCH 2013 ANA FILIPA FREITAS INÊS FIGUEIREDO MARIA INÊS GONÇALVES MARIANA FERREIRA

SUMMARY � Definition � Mechanism � Types � � � Germinal Somatic Mixed � Associated Diseases � Impact on the Disease � Heteroplasmy � Clinical Cases � � Cancer Down Syndrome � Prenatal Diagnosis and Pseudomosaicism � References 2

MOSAICISM – THE DEFINITION (Reproduced from: Read, A. ; Strachan, T. , 2011) “MOSAICISM is a condition in which is notted the presence of two or more different chromosomal complements in the same tissue. ” (Azevedo, C. ; Sunkel, C. E. , 2005) This condition can affect any type of cells. 3

MECHANISM OF FORMATION Nondisjunction MEIOSIS OR Premature centromer e division 4 MITOSIS Anaphase lag

MECHANISM OF FORMATION (Reproduced from: Azevedo, C. ; Sunkel, C. E. , 2005) COMPLETE PARTIAL NON-DISJUNCTION IN POST-ZYGOTICMITOTIC DIVISION 5

TYPES OF MOSAICISM � GERMINAL MOSAICISM � SOMATIC MOSAICISM � GERMINAL AND SOMATIC MOSAICISM 6

TYPES OF MOSAICISM � GERMINAL MOSAICISM 7 • Assintomatic • Only germinal cells are affected • Could be transmitted to descendents • Osteogenesis imperfecta type ll • Turner syndrome • Duchenne muscular distrophy • Haemophylia

TYPES OF MOSAICISM � SOMATIC MOSAICISM • Sintomatic • Somatic cells are affected • It’s not inherited Reproduce from: Health Encyclopedia of URMC 8 • Cancer • Neurofibrosis • Heterochromia iridum • Down syndrome

SOMATIC VS. GERMINAL MOSAICISM (A) Hypothetical pedigree of Segmental neurofibromitosis type 1 (AD) and (below) molecular analysis showing somatic mosaicism. 9 (B) Hypothetical pedigree and molecular analysis showing germ-line mosaicism in tuberous sclerosis (AD). (Reproduced from: Youssoufian, H. et al. , 2002)

HOW TO DETECT MOSAICISM? � Karyotype analysis � Fluorescent in situ hybridization (FISH) � Array Comparative genomic hybridization (array CGH) Composite array results for mosaic deletions and duplications. Reproduced from [3] 10 Examples of FISH results on fetal ovarian cells using two chromosome 21 specific probes. a) Location of the probes near the end of the long arm of chromosome 21. b) Normal cell nucleus showing two dual chromosome 21 -specific signals. c, d) T 21 cell nuclei showing three dual chromosome 21 -specific signals. Reproduced from [1]

MENDELIAN DISORDERS ASSOCIATED WITH MOSAICISM 11 CLASSIFICATION DISORDER Metabolic Disorders Tyrosinemia Type I Lesch-Nyhan Conradi-Hunermann-Happle Immune Dysfunction Adenosine Deaminase Deficiency Wiskott-Aldrich Syndrome Clotting Disorders Haemophilias A and B Skeletal Disorders Marfan Syndrome Pseudoachondroplasia Muscle Disorders Duchenne Musclar Dystrophy Congenital Myotonic Dystrophy Chromosomal Instability Bloom Syndrome Fanconi Anemia Tumor Supressor Neurofibromatosis Types I and II Tuberous Sclerosis Skin Disorders Bullous Ichthysiform Erythroderma Incontinentia Pigmenti Endocrine Disorders Androgen Insensitivity Nervous-System Disorders Friedreich Ataxia Table 1: Examples of additional Mendelian disorders associated with mosaicism Adapted from Youssoufian H. et. al. Human genetics and disease: Mechanisms and consequences of somatic mosaicism in humans. Nature Reviews Genetics 3, 748 -758.

MOSAICISM: THE IMPACT ON THE DISEASE � [1] The mosaicism effects depend on the: � Stage where the mutation occurs � Nature of the abnormal chromosomes changes � Proportion between normal and abnormal cells � Nature of the affected tissues 12 [1] Azevedo, C. ; Sunkel, C. E. , 2005

HETEROPLASMY 13 � Somatic mosaicism for mitochondrial disorders results from the random segregation of mutant and wild-type mitochondria during mitosis. � Daughter cells with different proportions mutated mitochondria. � The most severe mithocondrial diseases are heteroplasmic. (Reproduced from: Youssoufian, H. et al. , 2002)

CANCER � Several recent studies have reported, that the probability of progression to cancer can depend on the degree of mosaicism in a tissue. � Cancer control: can be caused by mutations in genes that encode or transcription factors � cell cycle checkpoint proteins � growth factors � repair proteins � telomerase � � The gene BUB 1 B, when mutant, causes a chromosomal instability that leads to cancer. it causes mosaic variegated aneuploidy, involving multiple different chromosomes and tissues. 14 S. A. Frank / Journal of Theoretical Biology 223 (2003) 405– 412

DOWN SYNDROME Free trisomy 21 Meiotic error All cells are trisomic Robertsonian translocation Kariotype: 46, XX or 46, XY Mosaic trisomy 21 Post-zygotic non-disjunction Two different lines of cells: Normal and Trisomic Free trisomy 21 in mosaic 15 Cell rescue

THE MOSAICISM IMPACT ON DOWN SYNDROME � Results in a highly variable clinical phenotype depending on: � the tissues involved � proportion of trisomic cells � the sequence of events leading to the mosaicism 16

THE MOSAICISM IMPACT ON DOWN SYNDROME Increases Leukemia Alzheimer’s Disease Immunodeficiency Infections Type 1 diabetes Hypothyroidism Asthma Premature aging Solid Cancers Decreases 17 According to Hultén et al. [2]

PRENATAL DIAGNOSIS AND PSEUDOMOSAICISM Amniocentisis Different cellular lines 18 1 individual culture 2 or more individual cultures Pseudomosaicism True Mosaicism

REFERENCES 23/02/13: � http: //www. nature. com/scitable/topicpage/somatic-mosaicism-and -chromosomal-disorders-867 � http: //www. chromosome 18. org/The. Conditions/Mosaicism/tabid/4 90/Default. aspx � http: //www. upf. edu/cexs/actualitat/geneticmosaic. html#. USl. I 1 q. Utx LY � http: //www. molecularcytogenetics. org/content/1/1/26 � http: //genomemedicine. com/content/pdf/gm 168. pdf � http: //en. wikipedia. org/wiki/Mosaic_(genetics) � http: //users. rcn. com/jkimball. ma. ultranet/Biology. Pages/M/Mosaics. html � http: //www. med. uc. edu/embryology/chapter 1/updates/mosaic. htm � http: //www. nlm. nih. gov/medlineplus/ency/article/001317. htm � http: //books. google. pt/books? id=h. SDrd 9 Mf. SCEC&pg=PA 555&dq=m osaicism&hl=pt. PT&sa=X&ei=t. U 8 p. Uaq. ILoi. Shgfuo. IDIAw&ved=0 CEs. Q 6 AEw. BQ#v=one page&q=mosaicism&f=false 19

REFERENCES 24/02/13: � http: //www. slideshare. net/rinaldowp/cnvs-e-mosaicismodurante-o-desenvovimento-somtico � http: //www. geocities. ws/carolparada/biologiamolecular/ mosaicismocromossomico. htm � http: //www. google. pt/books? hl=pt. PT&lr=&id=jkw 3 y 4 Dmr. M 4 C&oi=fnd&pg=PA 2&dq=mosaici smo+gen%C 3%A 9 tico&ots=Zm. NNg 537 Iz&sig=ZEp-bx. SUu_Ft_b 63 na. GJy 2 yd. RA&redir_esc=y#v=onepage&q=mosa icismo%20 gen%C 3%A 9 tico&f=false � http: //laboratoriogene. info/DXPN/index. htm � https: //www. urmc. rochester. edu/encyclopedia/content. as px? Content. Type. ID=90&Content. ID=P 02132 20

REFERENCES 25/02/13 � [1] Hultén MA, Patel SD, Tankimanova M, Westgren M, Papadogiannakis N, Jonsson AM, Iwarsson E. On the origin of trisomy 21 Down syndrome. Mol. Cytogenet. 2008; 1: 21. (http: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 2564957/) � [2] Hultén MA, Jonasson J, Nordgren A, Iwarsson E. On Germinal and Somatic Trisomy 21 Mosaicism: How Common is it, What are the Implications for Individual Carriers and How Does it Come About? . Curr Genomics. 2010 September; 11(6): 409– 419. (http: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 3018721/) � [3] Conlin LK, Thiel BD, Bonnemann CG, Medne L, Ernst LM, Zackai EH, Deardorff MA, Krantz ID, Hakonarson H, Spinner NB. Mechanisms of mosaicism, chimerism and uniparental disomy identified by single nucleotide polymorphism array analysis. Hum Mol Genet. 2010 April 1; 19(7): 1263– 1275. (http: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 3146011/) 21

REFERENCES 27/02/13: � http: //en. wikipedia. org/wiki/Heterochromia � http: //www. diagnosiprenatale. com/diagnosi-prenatale/mosaicismodiagnosi-prenatale. aspx � http: //downsyndrome. about. com/od/whatcausesdownsyndrome/a/m osaic_ro. htm � A. Paskulin, Giorgio; B. Lorenzen, Marina et all. (2011) Importance of the fibroblast chromosomal analysis in suspected cases of mosaicism: experience of a clinical Genetics service. Revista Paulista de Pediatria. ; 29(1): 73 -9. � Cunningham, Gary F. ; Leveno, Kenneth J. et all. (2012) Williams Obstetrics. 23 rd Edition. Mc. Graw-Hill. Cap 12, P. 275, 276. � Pierce, Benjamin A. ; (2004) Genética-Um Enfoque Conceitual. Cap 9, P. 246 -252. � Regateiro, Fernando J. (2007) Manual de Genética Médica. Cap IV. � Rodríguez-Santiago, Benjamín; Malats, Núria et all. (2010) Mosaic Uniparental Disomies and Aneuploidies as Large Structural Variants of the Human Genome. The American Journal of Human Genetics. July 9. P. 87, 129– 138. 22

REFERENCES 03/03/13 � Azevedo, C. ; Sunkel, C. E. (2005). Meiose e Aneuploidia in Biologia Celular e Molecular (pp. 397 -430). LIDEL-Edições Técnicas, Lisboa (Ed. ) � Lewis, Ricki. (2008) Human Genetics – Concepts and Applications; 8 th edition; chapters 5 (pp. 96 -98) and 18 (pp. 367 -373). Mc. Graw-Hill. � Read, A. ; Strachan, T. (2011). Human Molecular Genetics; 4 th edition; chapter 3; Garland Science � Youssoufian, H. et al. (2002). Mechanisms and consequences of somatic mosaicism in humans (pp. 749 -150). Nature Reviews Genetics 3. � Frank SA. Somatic mosaicism and cancer: inference based on a conditional Luria–Delbruck distribution. Department of Ecology and Evolutionary Biology, University of California. Journal of Theoretical Biology 223 (2003) 405– 412 (http: //stevefrank. org/reprints-pdf/03 JTB-LD. pdf) http: //www. ncbi. nlm. nih. gov/omim � http: //www. uc. pt/fmuc/citogenetica/genomica/indicacoes � 23

QUESTIONS? 24