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Lund ICB, Becher N, Graakjaer J, Lildballe DL, Uldbjerg N, Bogaard P, Petersen A, Vestergaard EM, Vogel I. Mosaicism for copy number variations in the placenta is even more difficult to interpret than mosaicism for whole chromosome aneuploidy. Prenat Diagn 2021; 41:668-680. [PMID: 33843057 DOI: 10.1002/pd.5938] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/09/2021] [Accepted: 03/22/2021] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To compare mosaicisms in prenatal chorionic villus samples (CVSs) with corresponding postpartum placental samples. METHOD We collected placentas from 15 consecutive cases of mosaicism detected in CVSs and obtained five standardized samples on each placenta after delivery. All pre- and postnatal placental samples were uncultured and analyzed by high-resolution chromosomal microarray. RESULTS Ten cases of mosaicism for whole chromosome aneuploidy (mWC) and five cases with mosaicism for (sub)chromosomal copy number variations (mCNVs) were included. In 5/10 mWC cases and in 4/5 mCNV cases the prenatally detected aberration was confirmed in the postpartum placenta. Three postpartum placentas revealed various complex aberrations differing from the prenatal results: (1) mosaicisms for different deletions/duplications on 9p and 9q in all samples (prenatal: mosaic 5.3 Mb duplication on 9p24), (2) different regions with deletions/duplications/loss of heterozygosity on 1p in all samples (prenatal: mosaic 2.3 Mb 1p36 duplication), and (3) mosaicism for a duplication on 5q and a deletion on 6p in one out of five samples (prenatal: mosaic trisomy 7). CONCLUSION CNVs constitute a complex subgroup in placental mosaicism. Counseling of these couples after chorionic villus sampling should not focus on the specific CNV involved, but on the nature of mosaicism and the option of amniocentesis and ultrasound.
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Affiliation(s)
- Ida C Bay Lund
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark.,Center for Fetal Diagnostics, Aarhus University Hospital, Aarhus, Denmark.,Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Naja Becher
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark.,Center for Fetal Diagnostics, Aarhus University Hospital, Aarhus, Denmark.,Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Jesper Graakjaer
- Department of Clinical Genetics, University Hospital of Southern Denmark, Sygehus Lillebaelt, Vejle, Denmark
| | - Dorte L Lildballe
- Center for Fetal Diagnostics, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Genetics, University Hospital of Southern Denmark, Sygehus Lillebaelt, Vejle, Denmark
| | - Niels Uldbjerg
- Department of Obstetrics and Gynaecology, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Pauline Bogaard
- Department of Pathology, Aalborg University Hospital, Aalborg, Denmark
| | - Astrid Petersen
- Department of Pathology, Aalborg University Hospital, Aalborg, Denmark
| | - Else M Vestergaard
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark.,Center for Fetal Diagnostics, Aarhus University Hospital, Aarhus, Denmark
| | - Ida Vogel
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark.,Center for Fetal Diagnostics, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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2
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Eno CC, Graakjaer J, Svaneby D, Nizon M, Kianmahd J, Signer R, Martinez-Agosto JA, Quintero-Rivera F. 14q32.11 microdeletion including CALM1, TTC7B, PSMC1, and RPS6KA5: A new potential cause of developmental and language delay in three unrelated patients. Am J Med Genet A 2021; 185:1519-1524. [PMID: 33634591 DOI: 10.1002/ajmg.a.62117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 12/14/2020] [Accepted: 01/23/2021] [Indexed: 12/18/2022]
Abstract
Three unrelated patients with similar microdeletions of chromosome 14q32.11 with shared phenotypes including language and developmental delay, and four overlapping genes -CALM1, TTC7B, PSMC1, and RPS6KA5 have been presented. All four genes are expressed in the brain and have haploinsufficiency scores, which reflect low tolerance to loss of function variation. An insight on the genes in the overlapping region, which may influence the resulting phenotype has been provided. Given the three patients' similar phenotypes and lack of normal variation in this region, it was suggested that this microdeletion may be associated with developmental and language delay.
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Affiliation(s)
- Celeste C Eno
- Department of Academic Pathology, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Jesper Graakjaer
- Department of Clinical Genetics, Lillebaelt Hospital, Vejle, Denmark
| | - Dea Svaneby
- Department of Clinical Genetics, Lillebaelt Hospital, Vejle, Denmark
| | - Mathilde Nizon
- Department of Medical Genetics, CHU Nantes, Nantes, France
| | - Jessica Kianmahd
- Departments of Human Genetics and Pediatrics, Division of Medical Genetics, UCLA, Los Angeles, California, USA
| | - Rebecca Signer
- Departments of Human Genetics and Pediatrics, Division of Medical Genetics, UCLA, Los Angeles, California, USA
| | - Julian A Martinez-Agosto
- Departments of Human Genetics and Pediatrics, Division of Medical Genetics, UCLA, Los Angeles, California, USA
| | - Fabiola Quintero-Rivera
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, California, USA
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3
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Goharian TS, Fagerberg CR, Jensen BL, Graakjaer J, Brasch-Andersen C, Nybo M. Prostaglandin E 2
-EP 3
receptor subtype gene deletion in mother and son impairs platelet aggregation. Br J Haematol 2019. [DOI: 10.1111/bjh.15196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tina S. Goharian
- Department of Clinical Biochemistry and Pharmacology; Odense University Hospital; Odense Denmark
| | | | - Boye L. Jensen
- Institute of Physiology; University of Southern Denmark; Odense Denmark
| | - Jesper Graakjaer
- Department of Clinical Genetics; Lillebaelt Hospital Vejle; Vejle Denmark
| | | | - Mads Nybo
- Department of Clinical Biochemistry and Pharmacology; Odense University Hospital; Odense Denmark
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4
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Markholt S, Graakjaer J, Thim SB, Høst B, Skytte AB. A case of penta X syndrome caused by nondisjunction in maternal meiosis 1 and 2. Clin Case Rep 2017; 5:1136-1140. [PMID: 28680612 PMCID: PMC5494398 DOI: 10.1002/ccr3.1004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 01/02/2017] [Accepted: 04/17/2017] [Indexed: 12/04/2022] Open
Abstract
The prenatal abnormalities in patients with penta X syndrome appear late in pregnancy and are nonspecific. In contrast, the postnatal phenotype is well described although new findings are still revealed. Penta X syndrome is a result of successive nondisjunctions of the X chromosomes in both maternal meiotic divisions.
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Affiliation(s)
- Sara Markholt
- Department of Clinical Genetics; Aarhus University Hospital; Aarhus Denmark
| | - Jesper Graakjaer
- Department of Clinical Genetics; Lillebaelt Hospital; Vejle Denmark
| | - Signe Bødker Thim
- Department of Pediatrics; Aarhus University Hospital; Aarhus Denmark
| | - Bente Høst
- Department of Pediatrics; Aarhus University Hospital; Aarhus Denmark
| | - Anne-Bine Skytte
- Department of Clinical Genetics; Aarhus University Hospital; Aarhus Denmark
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5
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Rasmussen M, Vestergaard EM, Graakjaer J, Petkov Y, Bache I, Fagerberg C, Kibaek M, Svaneby D, Petersen OB, Brasch-Andersen C, Sunde L. 17q12 deletion and duplication syndrome in Denmark-A clinical cohort of 38 patients and review of the literature. Am J Med Genet A 2016; 170:2934-2942. [DOI: 10.1002/ajmg.a.37848] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 07/01/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Maria Rasmussen
- Department of Clinical Genetics; Aarhus University Hospital; Skejby Denmark
| | | | | | - Yanko Petkov
- Department of Pediatrics; Esbjerg Hospital; Denmark
| | - Iben Bache
- Department of Clinical Genetics; Rigshospitalet; Denmark
- Department of Cellular and Molecular Medicine; Wilhelm Johannsen Centre for Functional Genome Research; University of Copenhagen; Denmark
| | | | - Maria Kibaek
- Department of Pediatrics; Odense University Hospital; Denmark
| | - Dea Svaneby
- Department of Clinical Genetics; Vejle Hospital; Denmark
| | - Olav Bjørn Petersen
- Department of Gynecology and Obstetrics; Aarhus University Hospital; Skejby Denmark
| | | | - Lone Sunde
- Department of Clinical Genetics; Aarhus University Hospital; Skejby Denmark
- Department of Biomedicine; Aarhus University; Aarhus Denmark
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6
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Hatt L, Aagaard MM, Graakjaer J, Bach C, Sommer S, Agerholm IE, Kølvraa S, Bojesen A. Microarray-Based Analysis of Methylation Status of CpGs in Placental DNA and Maternal Blood DNA--Potential New Epigenetic Biomarkers for Cell Free Fetal DNA-Based Diagnosis. PLoS One 2015; 10:e0128918. [PMID: 26230497 PMCID: PMC4521692 DOI: 10.1371/journal.pone.0128918] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 05/03/2015] [Indexed: 11/18/2022] Open
Abstract
Epigenetic markers for cell free fetal DNA in the maternal blood circulation are highly interesting in the field of non-invasive prenatal testing since such markers will offer a possibility to quantify the amount of fetal DNA derived from different chromosomes in a maternal blood sample. The aim of the present study was to define new fetal specific epigenetic markers present in placental DNA that can be utilized in non-invasive prenatal diagnosis. We have conducted a high-resolution methylation specific beadchip microarray study assessing more than 450.000 CpG sites. We have analyzed the DNA methylation profiles of 10 maternal blood samples and compared them to 12 1st trimesters chorionic samples from normal placentas, identifying a number of CpG sites that are differentially methylated in maternal blood cells compared to chorionic tissue. To strengthen the utility of these differentially methylated CpG sites to be used with methyl-sensitive restriction enzymes (MSRE) in PCR-based NIPD, we furthermore refined the list of selected sites, containing a restriction sites for one of 16 different methylation-sensitive restriction enzymes. We present a list of markers on chromosomes 13, 18 and 21 with a potential for aneuploidy testing as well as a list of markers for regions harboring sub-microscopic deletion- or duplication syndromes.
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Affiliation(s)
- Lotte Hatt
- Department of Clinical Genetics, Vejle Hospital, 7100, Vejle, Denmark
- Department of Gynecology and Obstetrics, Horsens Hospital, 8700, Horsens, Denmark
- Institute of Regional Health research, University of Southern Denmark, 5000, Odense, Denmark
- * E-mail:
| | - Mads M. Aagaard
- Department of Clinical Genetics, Vejle Hospital, 7100, Vejle, Denmark
| | - Jesper Graakjaer
- Department of Clinical Genetics, Vejle Hospital, 7100, Vejle, Denmark
| | - Cathrine Bach
- Department of Gynecology and Obstetrics, Horsens Hospital, 8700, Horsens, Denmark
| | - Steffen Sommer
- Department of Gynecology and Obstetrics, Horsens Hospital, 8700, Horsens, Denmark
| | - Inge E. Agerholm
- Department of Gynecology and Obstetrics, Horsens Hospital, 8700, Horsens, Denmark
| | - Steen Kølvraa
- Department of Clinical Genetics, Vejle Hospital, 7100, Vejle, Denmark
- Institute of Regional Health research, University of Southern Denmark, 5000, Odense, Denmark
| | - Anders Bojesen
- Department of Clinical Genetics, Vejle Hospital, 7100, Vejle, Denmark
- Institute of Regional Health research, University of Southern Denmark, 5000, Odense, Denmark
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7
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Novara F, Stanzial F, Rossi E, Benedicenti F, Inzana F, Di Gregorio E, Brusco A, Graakjaer J, Fagerberg C, Belligni E, Silengo M, Zuffardi O, Ciccone R. Defining the phenotype associated with microduplication reciprocal to Sotos syndrome microdeletion. Am J Med Genet A 2014; 164A:2084-90. [PMID: 24819041 DOI: 10.1002/ajmg.a.36591] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 03/31/2014] [Indexed: 11/08/2022]
Abstract
NSD1 point mutations, submicroscopic deletions and intragenic deletions are the major cause of Sotos syndrome, characterized by pre-postnatal generalized overgrowth with advanced bone age, learning disability, seizures, distinctive facial phenotype. Reverse clinical phenotype due to 5q35 microduplication encompassing NSD1 gene has been reported so far in 27 cases presenting with delayed bone age, microcephaly, failure to thrive and seizures in some cases, further supporting a gene dosage effect of NSD1 on growth regulation and neurological functions. Here we depict the clinical presentation of three new cases with 5q35 microduplication outlining a novel syndrome characterized by microcephaly, short stature, developmental delay and in some cases delayed bone maturation, without any typical facial or osseous anomalies.
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Affiliation(s)
- Francesca Novara
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
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8
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Curry CJ, Rosenfeld JA, Grant E, Gripp KW, Anderson C, Aylsworth AS, Saad TB, Chizhikov VV, Dybose G, Fagerberg C, Falco M, Fels C, Fichera M, Graakjaer J, Greco D, Hair J, Hopkins E, Huggins M, Ladda R, Li C, Moeschler J, Nowaczyk MJM, Ozmore JR, Reitano S, Romano C, Roos L, Schnur RE, Sell S, Suwannarat P, Svaneby D, Szybowska M, Tarnopolsky M, Tervo R, Tsai ACH, Tucker M, Vallee S, Wheeler FC, Zand DJ, Barkovich AJ, Aradhya S, Shaffer LG, Dobyns WB. The duplication 17p13.3 phenotype: analysis of 21 families delineates developmental, behavioral and brain abnormalities, and rare variant phenotypes. Am J Med Genet A 2013; 161A:1833-52. [PMID: 23813913 DOI: 10.1002/ajmg.a.35996] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 03/31/2013] [Indexed: 11/11/2022]
Abstract
Chromosome 17p13.3 is a gene rich region that when deleted is associated with the well-known Miller-Dieker syndrome. A recently described duplication syndrome involving this region has been associated with intellectual impairment, autism and occasional brain MRI abnormalities. We report 34 additional patients from 21 families to further delineate the clinical, neurological, behavioral, and brain imaging findings. We found a highly diverse phenotype with inter- and intrafamilial variability, especially in cognitive development. The most specific phenotype occurred in individuals with large duplications that include both the YWHAE and LIS1 genes. These patients had a relatively distinct facial phenotype and frequent structural brain abnormalities involving the corpus callosum, cerebellar vermis, and cranial base. Autism spectrum disorders were seen in a third of duplication probands, most commonly in those with duplications of YWHAE and flanking genes such as CRK. The typical neurobehavioral phenotype was usually seen in those with the larger duplications. We did not confirm the association of early overgrowth with involvement of YWHAE and CRK, or growth failure with duplications of LIS1. Older patients were often overweight. Three variant phenotypes included cleft lip/palate (CLP), split hand/foot with long bone deficiency (SHFLD), and a connective tissue phenotype resembling Marfan syndrome. The duplications in patients with clefts appear to disrupt ABR, while the SHFLD phenotype was associated with duplication of BHLHA9 as noted in two recent reports. The connective tissue phenotype did not have a convincing critical region. Our experience with this large cohort expands knowledge of this diverse duplication syndrome.
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Barber J, Brasch-Andersen C, Maloney V, Huang S, Bateman M, Graakjaer J, Heinl U, Fagerberg C. A Novel Pseudo-Dicentric Variant of 16p11.2q11.2 Contains Euchromatin from 16p11.2p11.1 and Resembles Pathogenic Duplications of Proximal 16q. Cytogenet Genome Res 2013; 139:59-64. [DOI: 10.1159/000342542] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/04/2012] [Indexed: 01/12/2023] Open
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10
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Bygum A, Petkov Y, Graakjaer J, Jensen UB, Fagerberg C. Phylloid hypermelanosis in a child with psychomotor delay, cicatricial alopecia, hearing loss and polythelia. Acta Derm Venereol 2012; 92:191-2. [PMID: 22294434 DOI: 10.2340/00015555-1259] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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11
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Bischoff C, Graakjaer J, Petersen HC, Hjelmborg JVB, Vaupel JW, Bohr V, Koelvraa S, Christensen K. The Heritability of Telomere Length Among the Elderly and Oldest-Old. Twin Res Hum Genet 2012. [DOI: 10.1375/twin.8.5.433] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractA tight link exists between telomere length and both population doublings of a cell culture and age of a given organism. The more population doublings of the cell culture or the higher the age of the organism, the shorter the telomeres. The proposed model for telomere shortening, called the end replication problem, explains why the telomere erodes at each cellular turnover. Telomere length is regulated by a number of associated proteins through a number of different signaling pathways. The determinants of telomere length were studied using whole blood samples from 287 twin pairs aged 73 to 95 years. Structural equation models revealed that a model including additive genetic effects and non- shared environment was the best fitting model and that telomere length was moderately heritable, with an estimate that was sensitive to the telomere length standardization procedure. Sex-specific analyses showed lower heritability in males, although not statistically significant, which is in line with our earlier finding of a sex difference in telomere dynamics among the elderly and oldest-old.
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12
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Bischoff C, Graakjaer J, Petersen HC, Jeune B, Bohr VA, Koelvraa S, Christensen K. Telomere Length Among the Elderly and Oldest-Old. Twin Res Hum Genet 2012. [DOI: 10.1375/twin.8.5.425] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractHuman chromosomes terminate in a number of repeats of the sequence TTAGGG. At birth, each chromosome end is equipped with approximately 15 kb of telomere sequence, but this sequence is shortened during each cell division. In cell cultures telomere shortening is associated with senescence, a phenomenon that has also been observed in normal adult tissues, indicating that telomere loss is associated with organismal ageing. Previous work has established that the rate of telomere loss in humans is age dependent, and recent work shows a sex-specific difference in telomere length and shortening in individuals over the age span of 20 to 75 years. Here, terminal restriction fragment lengths on DNA purified from whole blood were measured to examine the mean telomere length in a cross-sectional cohort of 816 Danish individuals of age 73 to 101 years. In this age group, females show a linear correlation between telomere length and age, whereas the pattern tends to be nonlinear (quadratic in age) for males. This difference in telomere length dynamics between the 2 sexes may be caused by several different mechanisms, including differences in selection by mortality, differences in leukocyte population or different telomerase expression pattern.
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13
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Harbo M, Bendix L, Bay-Jensen AC, Graakjaer J, Søe K, Andersen TL, Kjaersgaard-Andersen P, Koelvraa S, Delaisse JM. The distribution pattern of critically short telomeres in human osteoarthritic knees. Arthritis Res Ther 2012; 14:R12. [PMID: 22257826 PMCID: PMC3392801 DOI: 10.1186/ar3687] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Revised: 11/17/2011] [Accepted: 01/18/2012] [Indexed: 12/25/2022] Open
Abstract
Introduction Telomere shortening is associated with a number of common age-related diseases. A role of telomere shortening in osteoarthritis (OA) has been suggested, mainly based on the assessment of mean telomere length in ex vivo expanded chondrocytes. We addressed this role directly in vivo by using a newly developed assay, which measures specifically the load of ultra-short single telomeres (below 1,500 base pairs), that is, the telomere subpopulation believed to promote cellular senescence. Methods Samples were obtained from human OA knees at two distances from the central lesion site. Each sample was split into three: one was used for quantification of ultra-short single telomeres through the Universal single telomere length assay (STELA), one for histological Mankin grading of OA, and one for mean telomere length measurement through quantitative fluorescence in situ hybridization (Q-FISH) as well as for assessment of senescence through quantification of senescence-associated heterochromatin foci (SAHF). Results The load of ultra-short telomeres as well as mean telomere length was significantly associated with proximity to lesions, OA severity, and senescence level. The degree of significance was higher when assessed through load of ultra-short telomeres per cell compared with mean telomere length. Conclusions These in vivo data, especially the quantification of ultra-short telomeres, stress a role of telomere shortening in human OA.
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Affiliation(s)
- Maria Harbo
- Department of Clinical Cell Biology, Vejle/Lillebaelt Hospital, Institute of Regional Health Research, University of Southern Denmark, Kabbeltoft 25, 7100 Vejle, Denmark.
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Walker RF, Pakula LC, Sutcliffe MJ, Kruk PA, Graakjaer J, Shay JW. A case study of “disorganized development” and its possible relevance to genetic determinants of aging. Mech Ageing Dev 2009; 130:350-6. [DOI: 10.1016/j.mad.2009.02.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2008] [Revised: 02/08/2009] [Accepted: 02/15/2009] [Indexed: 10/21/2022]
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15
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Graakjaer J, Christensen R, Kolvraa S, Serakinci N. Mesenchymal stem cells with high telomerase expression do not actively restore their chromosome arm specific telomere length pattern after exposure to ionizing radiation. BMC Mol Biol 2007; 8:49. [PMID: 17565702 PMCID: PMC1906829 DOI: 10.1186/1471-2199-8-49] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Accepted: 06/13/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Previous studies have demonstrated that telomeres in somatic cells are not randomly distributed at the end of the chromosomes. We hypothesize that these chromosome arm specific differences in telomere length (the telomere length pattern) may be actively maintained. In this study we investigate the existence and maintenance of the telomere length pattern in stem cells. For this aim we studied telomere length in primary human mesenchymal stem cells (hMSC) and their telomerase-immortalised counterpart (hMSC-telo1) during extended proliferation as well as after irradiation. Telomere lengths were measured using Fluorescence In Situ Hybridization (Q-FISH). RESULTS A telomere length pattern was found to exist in primary hMSC's as well as in hMSC-telo1. This pattern is similar to what was previously found in lymphocytes and fibroblasts. The cells were then exposed to a high dose of ionizing radiation. Irradiation caused profound changes in chromosome specific telomere lengths, effectively destroying the telomere length pattern. Following long term culturing after irradiation, a telomere length pattern was found to re-emerge. However, the new telomere length pattern did not resemble the telomere length pattern observed before irradiation. CONCLUSION Our findings indicate that a telomere length pattern does exist in mesenchymal stem cells and that the pattern is not actively re-established after destruction by irradiation.
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Affiliation(s)
- Jesper Graakjaer
- Department of Clinical Genetics, Vejle County Hospital, Vejle, Denmark
| | - Rikke Christensen
- Department of Anatomy and Neurobiology, Institute of Medical Biology, University of Southern Denmark, Odense, Denmark
| | - Steen Kolvraa
- Department of Clinical Genetics, Vejle County Hospital, Vejle, Denmark
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16
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Corydon C, Lindholt M, Knudsen EB, Graakjaer J, Corydon TJ, Dam-Johansen M. Capsulorhexis contraction after cataract surgery: Comparison of sharp anterior edge and modified anterior edge acrylic intraocular lenses. J Cataract Refract Surg 2007; 33:796-9. [PMID: 17466850 DOI: 10.1016/j.jcrs.2007.01.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Accepted: 01/14/2007] [Indexed: 11/16/2022]
Abstract
PURPOSE To evaluate the reduction in the anterior capsule opening after phacoemulsification, continuous curvilinear capsulorhexis, and implantation of 1 of 2 acrylic intraocular lenses (IOLs). SETTING Department of Ophthalmology, Vejle Hospital, Vejle, Denmark. METHODS Eighty-four patients (84 eyes) were included in a prospective randomized study. All had phacoemulsification followed by implantation of an IOL with a modified anterior edge (38 eyes) or a sharp anterior edge (46 eyes). One day (baseline) and 3 months postoperatively, the area of the anterior capsule opening was measured using retroillumination photographs. RESULTS There was a significant reduction in the area of the anterior capsule opening from 1 day to 3 months postoperatively in both groups (P<.001). There was no significant difference in the reduction in the anterior capsule opening between the modified-edge IOL and the sharp-edged IOL (P = .313). The shrinkage was independent of the area of the anterior capsule opening at baseline. CONCLUSIONS There was a reduction in the area of the anterior capsule opening in all patients. The design of the anterior edge of the 2 IOLs did not influence the degree of anterior capsule opening shrinkage. The shrinkage was independent of the size of the area 1 day postoperatively.
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Serakinci N, Christensen R, Graakjaer J, Cairney CJ, Keith WN, Alsner J, Saretzki G, Kolvraa S. Ectopically hTERT expressing adult human mesenchymal stem cells are less radiosensitive than their telomerase negative counterpart. Exp Cell Res 2007; 313:1056-67. [PMID: 17274981 DOI: 10.1016/j.yexcr.2007.01.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 12/21/2006] [Accepted: 01/03/2007] [Indexed: 10/23/2022]
Abstract
During the past several years increasing evidence indicating that the proliferation capacity of mammalian cells is highly radiosensitive, regardless of the species and the tissue of origin of the cells, has accumulated. It has also been shown that normal bone marrow cells of mice have a similar radiosensitivity to other mammalian cells so far tested. In this study, we investigated the genetic effects of ionizing radiation (2.5-15 Gy) on normal human mesenchymal stem cells and their telomerised counterpart hMSC-telo1. We evaluated overall genomic integrity, DNA damage/repair by applying a fluorescence-detected alkaline DNA unwinding assay together with Western blot analyses for phosphorylated H2AX and Q-FISH was applied for investigation of telomeric damage. Our results indicate that hMSC and TERT-immortalized hMSCs can cope with relatively high doses of gamma-rays and that overall DNA repair is similar in the two cell lines. The telomeres were extensively destroyed after irradiation in both cell types suggesting that telomere caps are especially sensitive to radiation. The TERT-immortalized hMSCs showed higher stability at telomeric regions than primary hMSCs indicating that cells with long telomeres and high telomerase activity have the advantage of re-establishing the telomeric caps.
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Affiliation(s)
- Nedime Serakinci
- Department of Human Genetics, University of Aarhus, Aarhus, Denmark.
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18
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Graakjaer J, Londono-Vallejo JA, Christensen K, Kølvraa S. The Pattern of Chromosome-Specific Variations in Telomere Length in Humans Shows Signs of Heritability and Is Maintained through Life. Ann N Y Acad Sci 2006; 1067:311-6. [PMID: 16804004 DOI: 10.1196/annals.1354.042] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This paper characterizes the distribution of telomere length on individual chromosome arms in humans. By fluorescent in situ hybridization (FISH), followed by computer-assisted analysis of digital images, it is shown that the distribution of telomere length on individual chromosome arms is not random, but that humans have a common telomere profile. This profile exists in lymphocytes, amniocytes and fibroblasts, and seems to be conserved during life. A closer look at the overall pattern of the profile shows that the length of the telomeres in general follows the total chromosome length. In addition to the common profile, it is found that each person has specific characteristics, which are also conserved throughout life. Studying both twins and families we have obtained indications that these individual characteristics are at least partly inherited. Altogether, our results suggest that the length of individual telomeres might occasionally play a role in the heritability of life span.
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Affiliation(s)
- J Graakjaer
- Institute of Human Genetics, University of Aarhus, Denmark
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Graakjaer J, Der-Sarkissian H, Schmitz A, Bayer J, Thomas G, Kolvraa S, Londoño-Vallejo JA. Allele-specific relative telomere lengths are inherited. Hum Genet 2006. [DOI: 10.1007/s00439-006-0158-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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20
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Bischoff C, Petersen HC, Graakjaer J, Andersen-Ranberg K, Vaupel JW, Bohr VA, Kølvraa S, Christensen K. No Association Between Telomere Length and Survival Among the Elderly and Oldest Old. Epidemiology 2006; 17:190-4. [PMID: 16477260 DOI: 10.1097/01.ede.0000199436.55248.10] [Citation(s) in RCA: 198] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The consistent findings of a negative correlation between telomere length and replicative potential of cultured cells, as well as a decreasing telomere length in a number of different tissues in humans with age, have led to the suggestion that telomeres play a role in cellular aging in vivo and ultimately even in organismal aging. Furthermore, one small longitudinal study of elderly individuals has suggested that longer telomeres are associated with better survival. METHODS Telomere length was measured as mean terminal restriction fragment length on blood cells from 812 persons, age 73 to 101 years, who participated in population-based surveys in 1997-1998. Among the participants were 652 twins. The participants were followed up through the Danish Civil Registration system until January 2005, at which time 412 (51%) were dead. RESULTS Univariate Cox regression analyses revealed that longer telomeres were associated with better survival (hazard ratios = 0.89 [95% confidence interval = 0.76-1.04] per 1 kb in males and 0.79 [0.72-0.88] per 1 kb in females, respectively). However, including age in the analyses changed the estimates to 0.97 (0.83-1.14) and 0.93 (0.85-1.03), respectively. Intrapair comparison showed that among 175 twin pairs in which at least one died during follow up, it was the twin with the shorter telomere length who died first in 97 (55%) of the pairs (95% confidence interval = 48-63%). We could not confirm the recently reported negative correlation between telomere length and obesity or between telomere length and smoking. CONCLUSION This longitudinal study of the elderly and oldest old does not support the hypothesis that telomere length is a predictor for remaining lifespan once age is controlled for.
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Affiliation(s)
- Claus Bischoff
- Institute of Human Genetics, Aarhus University, Aarhus C, Denmark
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21
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Bischoff C, Graakjaer J, Petersen HC, Hjelmborg JVB, Vaupel JW, Bohr V, Koelvraa S, Christensen K. The heritability of telomere length among the elderly and oldest-old. Twin Res Hum Genet 2006; 8:433-9. [PMID: 16212832 DOI: 10.1375/183242705774310141] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A tight link exists between telomere length and both population doublings of a cell culture and age of a given organism. The more population doublings of the cell culture or the higher the age of the organism, the shorter the telomeres. The proposed model for telomere shortening, called the end replication problem, explains why the telomere erodes at each cellular turnover. Telomere length is regulated by a number of associated proteins through a number of different signaling pathways. The determinants of telomere length were studied using whole blood samples from 287 twin pairs aged 73 to 95 years. Structural equation models revealed that a model including additive genetic effects and non-shared environment was the best fitting model and that telomere length was moderately heritable, with an estimate that was sensitive to the telomere length standardization procedure. Sex-specific analyses showed lower heritability in males, although not statistically significant, which is in line with our earlier finding of a sex difference in telomere dynamics among the elderly and oldest-old.
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22
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Abstract
Human chromosomes terminate in a number of repeats of the sequence TTAGGG. At birth, each chromosome end is equipped with approximately 15 kb of telomere sequence, but this sequence is shortened during each cell division. In cell cultures telomere shortening is associated with senescence, a phenomenon that has also been observed in normal adult tissues, indicating that telomere loss is associated with organismal ageing. Previous work has established that the rate of telomere loss in humans is age dependent, and recent work shows a sex-specific difference in telomere length and shortening in individuals over the age span of 20 to 75 years. Here, terminal restriction fragment lengths on DNA purified from whole blood were measured to examine the mean telomere length in a cross-sectional cohort of 816 Danish individuals of age 73 to 101 years. In this age group, females show a linear correlation between telomere length and age, whereas the pattern tends to be nonlinear (quadratic in age) for males. This difference in telomere length dynamics between the 2 sexes may be caused by several different mechanisms, including differences in selection by mortality, differences in leukocyte population or different telomerase expression pattern.
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Graakjaer J, Der-Sarkissian H, Schmitz A, Bayer J, Thomas G, Kolvraa S, Londoño-Vallejo JA. Allele-specific relative telomere lengths are inherited. Hum Genet 2006; 119:344-50. [PMID: 16440201 DOI: 10.1007/s00439-006-0137-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Accepted: 01/02/2006] [Indexed: 10/25/2022]
Abstract
Previous studies have indicated that single relative telomere lengths are defined in the zygote. In order to explore the possibility that single telomere lengths segregate in families, we compared relative telomere lengths obtained from allelic chromosome extremities transmitted from parent to child, representing a total of 31 independent meiotic events. We find a significant positive correlation of 0.65 (P=0.0004) between these telomere lengths, whereas the correlation between the non-transmitted parental homologue and the transmitted homologue in the child is not statistically significant (r=0.16; P=0.195). This study indicates that, even though there is a telomerase-mediated maintenance/elongation of telomeres in germ cells, allele-specific relative telomere lengths are preserved in the next generation.
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Affiliation(s)
- Jesper Graakjaer
- Telomeres and Cancer Lab, UMR7147, CNRS-I, Curie-UPMC, Paris, France
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Graakjaer J, Pascoe L, Der-Sarkissian H, Thomas G, Kolvraa S, Christensen K, Londoño-Vallejo JA. The relative lengths of individual telomeres are defined in the zygote and strictly maintained during life. Aging Cell 2004; 3:97-102. [PMID: 15153177 DOI: 10.1111/j.1474-9728.2004.00093.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Previous studies have indicated that average telomere length is partly inherited (Slagboom et al., 1994; Rufer et al., 1999) and that there is an inherited telomere pattern in each cell (Graakjaer et al., 2003); (Londoño-Vallejo et al., 2001). In this study, we quantify the importance of the initially inherited telomere lengths within cells, in relation to other factors that influence telomere length during life. We have estimated the inheritance by measuring telomere length in monozygotic (MZ) twins using Q-FISH with a telomere specific peptide nucleic acid (PNA)-probe. Homologous chromosomes were identified using subtelomeric polymorphic markers. We found that identical homologous telomeres from two aged MZ twins show significantly less differences in relative telomere length than when comparing the two homologues within one individual. This result means that towards the end of life, individual telomeres retain the characteristic relative length they had at the outset of life and that any length alteration during the lifespan impacts equally on genetically identical homologues. As the result applies across independent individuals, we conclude that, at least in lymphocytes, epigenetic/environmental effects on relative telomere length are relatively minor during life.
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Affiliation(s)
- Jesper Graakjaer
- Institute for Human Genetics, University of Aarhus, Aarhus, Denmark
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Opresko PL, Otterlei M, Graakjaer J, Bruheim P, Dawut L, Kølvraa S, May A, Seidman MM, Bohr VA. The Werner Syndrome Helicase and Exonuclease Cooperate to Resolve Telomeric D Loops in a Manner Regulated by TRF1 and TRF2. Mol Cell 2004; 14:763-74. [PMID: 15200954 DOI: 10.1016/j.molcel.2004.05.023] [Citation(s) in RCA: 232] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2003] [Revised: 04/27/2004] [Accepted: 04/27/2004] [Indexed: 11/25/2022]
Abstract
Werner syndrome (WS) is characterized by features of premature aging and is caused by loss of the RecQ helicase protein WRN. WS fibroblasts display defects associated with telomere dysfunction, including accelerated telomere erosion and premature senescence. In yeast, RecQ helicases act in an alternative pathway for telomere lengthening (ALT) via homologous recombination. We found that WRN associates with telomeres when dissociation of telomeric D loops is likely during replication and recombination. In human ALT cells, WRN associates directly with telomeric DNA. The majority of TRF1/PCNA colocalizing foci contained WRN in live S phase ALT cells but not in telomerase-positive HeLa cells. Biochemically, the WRN helicase and 3' to 5' exonuclease act simultaneously and cooperate to release the 3' invading tail from a telomeric D loop in vitro. The telomere binding proteins TRF1 and TRF2 limit digestion by WRN. We propose roles for WRN in dissociating telomeric structures in telomerase-deficient cells.
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Affiliation(s)
- Patricia L Opresko
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
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Graakjaer J, Bischoff C, Korsholm L, Holstebroe S, Vach W, Bohr VA, Christensen K, Kølvraa S. The pattern of chromosome-specific variations in telomere length in humans is determined by inherited, telomere-near factors and is maintained throughout life. Mech Ageing Dev 2003; 124:629-40. [PMID: 12735903 DOI: 10.1016/s0047-6374(03)00081-2] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In this study the telomere length distribution on individual chromosome arms in humans has been characterized. Using fluorescent in situ hybridisation (FISH) followed by computer-assisted analysis of digital images, we show that the distribution of telomere length on individual chromosome arms is not random, but that humans have a common telomere profile. This profile exists in both lymphocytes, amniocytes and fibroblasts, and is conserved during life until about the age of 100. We find that the length of the telomeres generally follows the length of the chromosomes and that the chromosome specific differences in telomere length are determined by factors located very distally on the chromosome arms. In addition to the common profile, we also find that each individual has specific characteristics. Based on analysis of both monozygotic and dizygotic twins, we find that these characteristics are partly inherited. For each chromosome, age-related chromosome loss correlates negatively with telomere length. This suggests that decrease in telomere length may be an element in age-related genome instability.
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Affiliation(s)
- Jesper Graakjaer
- Institute of Human Genetics, University of Aarhus, Bartholin Building, Vilhelm Meyers Alle, Denmark
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