@article{KuhtzSchneiderElHajjetal.2014, author = {Kuhtz, Juliane and Schneider, Eberhard and El Hajj, Nady and Zimmermann, Lena and Fust, Olga and Linek, Bartosz and Seufert, Rudolf and Hahn, Thomas and Schorsch, Martin and Haaf, Thomas}, title = {Epigenetic heterogeneity of developmentally important genes in human sperm: Implications for assisted reproduction outcome}, series = {Epigenetics}, volume = {9}, journal = {Epigenetics}, number = {12}, doi = {10.4161/15592294.2014.988063}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150261}, pages = {1648-1658}, year = {2014}, abstract = {The molecular basis of male infertility is poorly understood, the majority of cases remaining unsolved. The association of aberrant sperm DNA methylation patterns and compromised semen parameters suggests that disturbances in male germline epigenetic reprogramming contribute to this problem. So far there are only few data on the epigenetic heterogeneity of sperm within a given sample and how to select the best sperm for successful infertility treatment. Limiting dilution bisulfite sequencing of small pools of sperm from fertile donors did not reveal significant differences in the occurrence of abnormal methylation imprints between sperm with and without morphological abnormalities. Intracytoplasmic morphologically selected sperm injection was not associated with an improved epigenetic quality, compared to standard intracytoplasmatic sperm injection. Deep bisulfite sequencing (DBS) of 2 imprinted and 2 pluripotency genes in sperm from men attending a fertility center showed that in both samples with normozoospermia and oligoasthenoteratozoospermia (OAT) the vast majority of sperm alleles was normally (de)methylated and the percentage of epimutations (allele methylation errors) was generally low (<1\%). However, DBS allowed one to identify and quantify these rare epimutations with high accuracy. Sperm samples not leading to a pregnancy, in particular in the OAT group, had significantly more epimutations in the paternally methylated GTL2 gene than samples leading to a live birth. All 13 normozoospermic and 13 OAT samples leading to a child had <1\% GTL2 epimutations, whereas one (7\%) of 14 normozoospermic and 7 (50\%) of 14 OAT samples without pregnancy displayed 1-14\% GTL2 epimutations.}, language = {en} } @article{SchneiderPliushchElHajjetal.2010, author = {Schneider, Eberhard and Pliushch, Galyna and El Hajj, Nady and Galetzka, Danuta and Puhl, Alexander and Schorsch, Martin and Frauenknecht, Katrin and Riepert, Thomas and Tresch, Achim and Mueller, Annette M. and Coerdt, Wiltrud and Zechner, Ulrich and Haaf, Thomas}, title = {Spatial, temporal and interindividual epigenetic variation of functionally important DNA methylation patterns}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68371}, year = {2010}, abstract = {DNA methylation is an epigenetic modification that plays an important role in gene regulation. It can be influenced by stochastic events, environmental factors and developmental programs. However, little is known about the natural variation of genespecific methylation patterns. In this study, we performed quantitative methylation analyses of six differentially methylated imprinted genes (H19, MEG3, LIT1, NESP55, PEG3 and SNRPN), one hypermethylated pluripotency gene (OCT4) and one hypomethylated tumor suppressor gene (APC) in chorionic villus, fetal and adult cortex, and adult blood samples. Both average methylation level and range of methylation variation depended on the gene locus, tissue type and/or developmental stage. We found considerable variability of functionally important methylation patterns among unrelated healthy individuals and a trend toward more similar methylation levels in monozygotic twins than in dizygotic twins. Imprinted genes showed relatively little methylation changes associated with aging in individuals who are >25 years. The relative differences in methylation among neighboring CpGs in the generally hypomethylated APC promoter may not only reflect stochastic fluctuations but also depend on the tissue type. Our results are consistent with the view that most methylation variation may arise after fertilization, leading to epigenetic mosaicism.}, subject = {Medizin}, language = {en} } @article{PrellSenPotabattulaetal.2022, author = {Prell, Andreas and Sen, Mustafa Orkun and Potabattula, Ramya and Bernhardt, Laura and Dittrich, Marcus and Hahn, Thomas and Schorsch, Martin and Zacchini, Federica and Ptak, Grazyna Ewa and Niemann, Heiner and Haaf, Thomas}, title = {Species-specific paternal age effects and sperm methylation levels of developmentally important genes}, series = {Cells}, volume = {11}, journal = {Cells}, number = {4}, issn = {2073-4409}, doi = {10.3390/cells11040731}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262301}, year = {2022}, abstract = {A growing number of sperm methylome analyses have identified genomic loci that are susceptible to paternal age effects in a variety of mammalian species, including human, bovine, and mouse. However, there is little overlap between different data sets. Here, we studied whether or not paternal age effects on the sperm epigenome have been conserved in mammalian evolution and compared methylation patterns of orthologous regulatory regions (mainly gene promoters) containing both conserved and non-conserved CpG sites in 94 human, 36 bovine, and 94 mouse sperm samples, using bisulfite pyrosequencing. We discovered three (NFKB2, RASGEF1C, and RPL6) age-related differentially methylated regions (ageDMRs) in humans, four (CHD7, HDAC11, PAK1, and PTK2B) in bovines, and three (Def6, Nrxn2, and Tbx19) in mice. Remarkably, the identified sperm ageDMRs were all species-specific. Most ageDMRs were in genomic regions with medium methylation levels and large methylation variation. Orthologous regions in species not showing this age effect were either hypermethylated (>80\%) or hypomethylated (<20\%). In humans and mice, ageDMRs lost methylation, whereas bovine ageDMRs gained methylation with age. Our results are in line with the hypothesis that sperm ageDMRs are in regions under epigenomic evolution and may be part of an epigenetic mechanism(s) for lineage-specific environmental adaptations and provide a solid basis for studies on downstream effects in the genes analyzed here.}, language = {en} } @article{FiedlerHirschElHajjetal.2019, author = {Fiedler, David and Hirsch, Daniela and El Hajj, Nady and Yang, Howard H. and Hu, Yue and Sticht, Carsten and Nanda, Indrajit and Belle, Sebastian and Rueschoff, Josef and Lee, Maxwell P. and Ried, Thomas and Haaf, Thomas and Gaiser, Timo}, title = {Genome-wide DNA methylation analysis of colorectal adenomas with and without recurrence reveals an association between cytosine-phosphate-guanine methylation and histological subtypes}, series = {Genes, Chromosomes and Cancer}, volume = {58}, journal = {Genes, Chromosomes and Cancer}, number = {11}, doi = {10.1002/gcc.22787}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-212676}, pages = {783 -- 797}, year = {2019}, abstract = {Aberrant methylation of DNA is supposed to be a major and early driver of colonic adenoma development, which may result in colorectal cancer (CRC). Although gene methylation assays are used already for CRC screening, differential epigenetic alterations of recurring and nonrecurring colorectal adenomas have yet not been systematically investigated. Here, we collected a sample set of formalin-fixed paraffin-embedded colorectal low-grade adenomas (n = 72) consisting of primary adenomas without and with recurrence (n = 59), recurrent adenomas (n = 10), and normal mucosa specimens (n = 3). We aimed to unveil differentially methylated CpG positions (DMPs) across the methylome comparing not only primary adenomas without recurrence vs primary adenomas with recurrence but also primary adenomas vs recurrent adenomas using the Illumina Human Methylation 450K BeadChip array. Unsupervised hierarchical clustering exhibited a significant association of methylation patterns with histological adenoma subtypes. No significant DMPs were identified comparing primary adenomas with and without recurrence. Despite that, a total of 5094 DMPs (false discovery rate <0.05; fold change >10\%) were identified in the comparisons of recurrent adenomas vs primary adenomas with recurrence (674; 98\% hypermethylated), recurrent adenomas vs primary adenomas with and without recurrence (241; 99\% hypermethylated) and colorectal adenomas vs normal mucosa (4179; 46\% hypermethylated). DMPs in cytosine-phosphate-guanine (CpG) islands were frequently hypermethylated, whereas open sea- and shelf-regions exhibited hypomethylation. Gene ontology analysis revealed enrichment of genes associated with the immune system, inflammatory processes, and cancer pathways. In conclusion, our methylation data could assist in establishing a more robust and reproducible histological adenoma classification, which is a prerequisite for improving surveillance guidelines.}, language = {en} } @article{SchneiderElHajjMuelleretal.2015, author = {Schneider, Eberhard and El Hajj, Nady and M{\"u}ller, Fabian and Navarro, Bianca and Haaf, Thomas}, title = {Epigenetic Dysregulation in the Prefrontal Cortex of Suicide Completers}, series = {Cytogenetic and Genome Research}, volume = {146}, journal = {Cytogenetic and Genome Research}, number = {1}, issn = {1424-8581}, doi = {10.1159/000435778}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-199032}, pages = {19-27}, year = {2015}, abstract = {The epigenome is thought to mediate between genes and the environment, particularly in response to adverse life experiences. Similar to other psychiatric diseases, the suicide liability of an individual appears to be influenced by many genetic factors of small effect size as well as by environmental stressors. To identify epigenetic marks associated with suicide, which is considered the endpoint of complex gene-environment interactions, we compared the cortex DNA methylation patterns of 6 suicide completers versus 6 non-psychiatric sudden-death controls, using Illumina 450K methylation arrays. Consistent with a multifactorial disease model, we found DNA methylation changes in a large number of genes, but no changes with large effects reaching genome-wide significance. Global methylation of all analyzed CpG sites was significantly (0.25 percentage point) lower in suicide than in control brains, whereas the vast majority (97\%) of the top 1,000 differentially methylated regions (DMRs) were higher methylated (0.6 percentage point) in suicide brains. Annotation analysis of the top 1,000 DMRs revealed an enrichment of differentially methylated promoters in functional categories associated with transcription and expression in the brain. In addition, we performed a comprehensive literature research to identify suicide genes that have been replicated in independent genetic association, brain methylation and/or expression studies. Although, in general, there was no significant overlap between different published data sets or between our top 1,000 DMRs and published data sets, our methylation screen strengthens a number of candidate genes (APLP2, BDNF, HTR1A, NUAK1, PHACTR3, MSMP, SLC6A4, SYN2, and SYNE2) and supports a role for epigenetics in the pathophysiology of suicide.}, language = {en} } @article{SchmidSteinleinHaafetal.2014, author = {Schmid, Michael and Steinlein, Claus and Haaf, Thomas and Mijares-Urrutia, Abraham}, title = {Nascent ZW Sex Chromosomes in Thecadactylus rapicauda (Reptilia, Squamata, Phyllodactylidae)}, series = {Cytogenetic and Genome Research}, volume = {143}, journal = {Cytogenetic and Genome Research}, number = {4}, issn = {1424-8581}, doi = {10.1159/000366212}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-199041}, pages = {259-267}, year = {2014}, abstract = {The chromosomes of the turnip-tailed gecko Thecadactylus rapicauda from the Falc{\´o}n State in northern Venezuela were examined by means of conventional staining, a variety of banding techniques and in situ hybridization with an 18S + 28S rDNA probe. In female specimens, C-banding analyses detected a cryptic W sex chromosome-associated interstitial heterochromatic segment which is absent in the Z sex chromosome. These ZW sex chromosomes are considered to be in a nascent stage of morphological differentiation and are absent in T. rapicauda collected in Guatemala. The amount, location and fluorochrome affinities of constitutive heterochromatin, the position of the nucleolus organizer region, and the genome sizes of female and male individuals were determined. The previously published cytogenetic data on T. rapicauda are discussed.}, language = {en} } @article{SchneiderElHajjHaaf2014, author = {Schneider, Eberhard and El Hajj, Nady and Haaf, Thomas}, title = {Epigenetic Information from Ancient DNA Provides New Insights into Human Evolution}, series = {Brain, Behavior and Evolution}, volume = {84}, journal = {Brain, Behavior and Evolution}, number = {3}, issn = {0006-8977}, doi = {10.1159/000365650}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196800}, pages = {169-171}, year = {2014}, abstract = {No abstract available.}, language = {en} } @article{PootHaaf2015, author = {Poot, Martin and Haaf, Thomas}, title = {Mechanisms of Origin, Phenotypic Effects and Diagnostic Implications of Complex Chromosome Rearrangements}, series = {Molecular Syndromology}, volume = {6}, journal = {Molecular Syndromology}, number = {3}, issn = {1661-8769}, doi = {10.1159/000438812}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196524}, pages = {110-134}, year = {2015}, abstract = {Complex chromosome rearrangements (CCRs) are currently defined as structural genome variations that involve more than 2 chromosome breaks and result in exchanges of chromosomal segments. They are thought to be extremely rare, but their detection rate is rising because of improvements in molecular cytogenetic technology. Their population frequency is also underestimated, since many CCRs may not elicit a phenotypic effect. CCRs may be the result of fork stalling and template switching, microhomology-mediated break-induced repair, breakage-fusion-bridge cycles, or chromothripsis. Patients with chromosomal instability syndromes show elevated rates of CCRs due to impaired DNA double-strand break responses during meiosis. Therefore, the putative functions of the proteins encoded by ATM, BLM, WRN, ATR, MRE11, NBS1, and RAD51 in preventing CCRs are discussed. CCRs may exert a pathogenic effect by either (1) gene dosage-dependent mechanisms, e.g. haploinsufficiency, (2) mechanisms based on disruption of the genomic architecture, such that genes, parts of genes or regulatory elements are truncated, fused or relocated and thus their interactions disturbed - these mechanisms will predominantly affect gene expression - or (3) mixed mutation mechanisms in which a CCR on one chromosome is combined with a different type of mutation on the other chromosome. Such inferred mechanisms of pathogenicity need corroboration by mRNA sequencing. Also, future studies with in vitro models, such as inducible pluripotent stem cells from patients with CCRs, and transgenic model organisms should substantiate current inferences regarding putative pathogenic effects of CCRs. The ramifications of the growing body of information on CCRs for clinical and experimental genetics and future treatment modalities are briefly illustrated with 2 cases, one of which suggests KDM4C(JMJD2C) as a novel candidate gene for mental retardation.}, language = {en} } @article{AlmanzarKleinSchmalzingetal.2016, author = {Almanzar, Giovanni and Klein, Matthias and Schmalzing, Marc and Hilligardt, Deborah and El Hajj, Nady and Kneitz, Hermann and Wild, Vanessa and Rosenwald, Andreas and Benoit, Sandrine and Hamm, Henning and Tony, Hans-Peter and Haaf, Thomas and Goebeler, Matthias and Prelog, Martina}, title = {Disease Manifestation and Inflammatory Activity as Modulators of Th17/Treg Balance and RORC/FoxP3 Methylation in Systemic Sclerosis}, series = {International Archives of Allergy and Immunology}, volume = {171}, journal = {International Archives of Allergy and Immunology}, number = {2}, issn = {1018-2438}, doi = {10.1159/000450949}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196577}, pages = {141-154}, year = {2016}, abstract = {Background: There is much evidence that T cells are strongly involved in the pathogenesis of localized and systemic forms of scleroderma (SSc). A dysbalance between FoxP3+ regulatory CD4+ T cells (Tregs) and inflammatory T-helper (Th) 17 cells has been suggested. Methods: The study aimed (1) to investigate the phenotypical and functional characteristics of Th17 and Tregs in SSc patients depending on disease manifestation (limited vs. diffuse cutaneous SSc, dcSSc) and activity, and (2) the transcriptional level and methylation status of Th17- and Treg-specific transcription factors. Results: There was a concurrent accumulation of circulating peripheral IL-17-producing CCR6+ Th cells and FoxP3+ Tregs in patients with dcSSc. At the transcriptional level, Th17- and Treg-associated transcription factors were elevated in SSc. A strong association with high circulating Th17 and Tregs was seen with early, active, and severe disease presentation. However, a diminished suppressive function on autologous lymphocytes was found in SSc-derived Tregs. Significant relative hypermethylation was seen at the gene level for RORC1 and RORC2 in SSc, particularly in patients with high inflammatory activity. Conclusions: Besides the high transcriptional activity of T cells, attributed to Treg or Th17 phenotype, in active SSc disease, Tregs may be insufficient to produce high amounts of IL-10 or to control proliferative activity of effector T cells in SSc. Our results suggest a high plasticity of Tregs strongly associated with the Th17 phenotype. Future directions may focus on enhancing Treg functions and stabilization of the Treg phenotype.}, language = {en} } @article{SchmidSteinleinFeichtingeretal.2014, author = {Schmid, Michael and Steinlein, Claus and Feichtinger, Wolfgang and Haaf, Thomas and Mijares-Urrutia, Abraham and Schargel, Walter E. and Hedges, S. Blair}, title = {Cytogenetic Studies on Gonatodes (Reptilia, Squamata, Sphaerodactylidae)}, series = {Cytogenetic and Genome Research}, volume = {144}, journal = {Cytogenetic and Genome Research}, number = {1}, issn = {1424-8581}, doi = {10.1159/000367929}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196753}, pages = {47-61}, year = {2014}, abstract = {Mitotic and meiotic chromosomes of 5 species of the reptile genus Gonatodes are described by means of conventional staining, banding analyses and in situ hybridization using a synthetic telomeric DNA probe. The amount, location and fluorochrome affinities of constitutive heterochromatin, the number and positions of nucleolus organizer regions, and the patterns of telomeric DNA sequences were determined for most of the species. The karyotypes of G. falconensis and G. taniae from northern Venezuela are distinguished by their extraordinarily reduced diploid chromosome number of 2n = 16, which is the lowest value found so far in reptiles. In contrast to most other reptiles, both species have exclusively large biarmed (meta- and submetacentric) chromosomes. Comparison of the karyotypes of G. falconensis and G. taniae with those of other Gonatodes species indicates that the exceptional 2n = 16 karyotype originated by a series of 8 centric fusions. The karyotypes of G. falconensis and G. taniae are further characterized by the presence of considerable amounts of (TTAGGG)n telomeric sequences in the centromeric regions of all chromosomes. These are probably not only relics of the centric fusion events, but a component of the highly repetitive DNA in the constitutive heterochromatin of the chromosomes. The genome sizes of 4 Gonatodes species were determined using flow cytometry. For comparative purposes, all previously published cytogenetic data on Gonatodes and other sphaerodactylids are included and discussed.}, language = {en} } @article{MaierhoferFlunkertOshimaetal.2019, author = {Maierhofer, Anna and Flunkert, Julia and Oshima, Junko and Martin, George M. and Poot, Martin and Nanda, Indrajit and Dittrich, Marcus and M{\"u}ller, Tobias and Haaf, Thomas}, title = {Epigenetic signatures of Werner syndrome occur early in life and are distinct from normal epigenetic aging processes}, series = {Aging Cell}, volume = {18}, journal = {Aging Cell}, doi = {10.1111/acel.12995}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202733}, pages = {e12995}, year = {2019}, abstract = {Werner Syndrome (WS) is an adult-onset segmental progeroid syndrome. Bisulfite pyrosequencing of repetitive DNA families revealed comparable blood DNA methylation levels between classical (18 WRN-mutant) or atypical WS (3 LMNA-mutant and 3 POLD1-mutant) patients and age- and sex-matched controls. WS was not associated with either age-related accelerated global losses of ALU, LINE1, and α-satellite DNA methylations or gains of rDNA methylation. Single CpG methylation was analyzed with Infinium MethylationEPIC arrays. In a correspondence analysis, atypical WS samples clustered together with the controls and were clearly separated from classical WS, consistent with distinct epigenetic pathologies. In classical WS, we identified 659 differentially methylated regions (DMRs) comprising 3,656 CpG sites and 613 RefSeq genes. The top DMR was located in the HOXA4 promoter. Additional DMR genes included LMNA, POLD1, and 132 genes which have been reported to be differentially expressed in WRN-mutant/depleted cells. DMRs were enriched in genes with molecular functions linked to transcription factor activity and sequence-specific DNA binding to promoters transcribed by RNA polymerase II. We propose that transcriptional misregulation of downstream genes by the absence of WRN protein contributes to the variable premature aging phenotypes of WS. There were no CpG sites showing significant differences in DNA methylation changes with age between WS patients and controls. Genes with both WS- and age-related methylation changes exhibited a constant offset of methylation between WRN-mutant patients and controls across the entire analyzed age range. WS-specific epigenetic signatures occur early in life and do not simply reflect an acceleration of normal epigenetic aging processes.}, language = {en} } @article{ElHajjDittrichBoecketal.2016, author = {El Hajj, Nady and Dittrich, Marcus and B{\"o}ck, Julia and Kraus, Theo F. J. and Nanda, Indrajit and M{\"u}ller, Tobias and Seidmann, Larissa and Tralau, Tim and Galetzka, Danuta and Schneider, Eberhard and Haaf, Thomas}, title = {Epigenetic dysregulation in the developing Down syndrome cortex}, series = {Epigenetics}, volume = {11}, journal = {Epigenetics}, number = {8}, doi = {10.1080/15592294.2016.1192736}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191239}, pages = {563-578}, year = {2016}, abstract = {Using Illumina 450K arrays, 1.85\% of all analyzed CpG sites were significantly hypermethylated and 0.31\% hypomethylated in fetal Down syndrome (DS) cortex throughout the genome. The methylation changes on chromosome 21 appeared to be balanced between hypo- and hyper-methylation, whereas, consistent with prior reports, all other chromosomes showed 3-11times more hyper- than hypo-methylated sites. Reduced NRSF/REST expression due to upregulation of DYRK1A (on chromosome 21q22.13) and methylation of REST binding sites during early developmental stages may contribute to this genome-wide excess of hypermethylated sites. Upregulation of DNMT3L (on chromosome 21q22.4) could lead to de novo methylation in neuroprogenitors, which then persists in the fetal DS brain where DNMT3A and DNMT3B become downregulated. The vast majority of differentially methylated promoters and genes was hypermethylated in DS and located outside chromosome 21, including the protocadherin gamma (PCDHG) cluster on chromosome 5q31, which is crucial for neural circuit formation in the developing brain. Bisulfite pyrosequencing and targeted RNA sequencing showed that several genes of PCDHG subfamilies A and B are hypermethylated and transcriptionally downregulated in fetal DS cortex. Decreased PCDHG expression is expected to reduce dendrite arborization and growth in cortical neurons. Since constitutive hypermethylation of PCDHG and other genes affects multiple tissues, including blood, it may provide useful biomarkers for DS brain development and pharmacologic targets for therapeutic interventions.}, language = {en} } @article{WeisSchoenVictoretal.2011, author = {Weis, Eva and Schoen, Holger and Victor, Anja and Spix, Claudia and Ludwig, Marco and Schneider-Raetzke, Brigitte and Kohlschmidt, Nicolai and Bartsch, Oliver and Gerhold-Ay, Aslihan and Boehm, Nils and Grus, Franz and Haaf, Thomas and Galetzka, Danuta}, title = {Reduced mRNA and Protein Expression of the Genomic Caretaker RAD9A in Primary Fibroblasts of Individuals with Childhood and Independent Second Cancer}, series = {PLoS ONE}, volume = {6}, journal = {PLoS ONE}, number = {10}, doi = {10.1371/journal.pone.0025750}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141838}, pages = {e25750}, year = {2011}, abstract = {Background: The etiology of secondary cancer in childhood cancer survivors is largely unclear. Exposure of normal somatic cells to radiation and/or chemotherapy can damage DNA and if not all DNA lesions are properly fixed, the mis-repair may lead to pathological consequences. It is plausible to assume that genetic differences, i.e. in the pathways responsible for cell cycle control and DNA repair, play a critical role in the development of secondary cancer. Methodology/Findings: To identify factors that may influence the susceptibility for second cancer formation, we recruited 20 individuals who survived a childhood malignancy and then developed a second cancer as well as 20 carefully matched control individuals with childhood malignancy but without a second cancer. By antibody microarrays, we screened primary fibroblasts of matched patients for differences in the amount of representative DNA repair-associated proteins. We found constitutively decreased levels of RAD9A and several other DNA repair proteins in two-cancer patients, compared to one-cancer patients. The RAD9A protein level increased in response to DNA damage, however to a lesser extent in the two-cancer patients. Quantification of mRNA expression by real-time RT PCR revealed lower RAD9A mRNA levels in both untreated and 1 Gy gamma-irradiated cells of two-cancer patients. Conclusions/Significance: Collectively, our results support the idea that modulation of RAD9A and other cell cycle arrest and DNA repair proteins contribute to the risk of developing a second malignancy in childhood cancer patients.}, language = {en} } @article{SchneiderDittrichBoecketal.2016, author = {Schneider, Eberhard and Dittrich, Marcus and B{\"o}ck, Julia and Nanda, Indrajit and M{\"u}ller, Tobias and Seidmann, Larissa and Tralau, Tim and Galetzka, Danuta and El Hajj, Nady and Haaf, Thomas}, title = {CpG sites with continuously increasing or decreasing methylation from early to late human fetal brain development}, series = {Gene}, volume = {592}, journal = {Gene}, number = {1}, doi = {10.1016/j.gene.2016.07.058}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186936}, pages = {110-118}, year = {2016}, abstract = {Normal human brain development is dependent on highly dynamic epigenetic processes for spatial and temporal gene regulation. Recent work identified wide-spread changes in DNA methylation during fetal brain development. We profiled CpG methylation in frontal cortex of 27 fetuses from gestational weeks 12-42, using Illumina 450K methylation arrays. Sites showing genome-wide significant correlation with gestational age were compared to a publicly available data set from gestational weeks 3-26. Altogether, we identified 2016 matching developmentally regulated differentially methylated positions (m-dDMPs): 1767 m-dDMPs were hypermethylated and 1149 hypomethylated during fetal development. M-dDMPs are underrepresented in CpG islands and gene promoters, and enriched in gene bodies. They appear to cluster in certain chromosome regions. M-dDMPs are significantly enriched in autism-associated genes and CpGs. Our results promote the idea that reduced methylation dynamics during fetal brain development may predispose to autism. In addition, m-dDMPs are enriched in genes with human-specific brain expression patterns and/or histone modifications. Collectively, we defined a subset of dDMPs exhibiting constant methylation changes from early to late pregnancy. The same epigenetic mechanisms involving methylation changes in cis-regulatory regions may have been adopted for human brain evolution and ontogeny.}, language = {en} } @article{WeisSchoenVictoretal.2011, author = {Weis, Eva and Schoen, Holger and Victor, Anja and Spix, Claudia and Ludwig, Marco and Schneider-Raetzke, Brigitte and Kohlschmidt, Nicolai and Bartsch, Oliver and Gerhold-Ay, Aslihan and Boehm, Nils and Grus, Franz and Haaf, Thomas and Galetzka, Danuta}, title = {Reduced mRNA and Protein Expression of the Genomic Caretaker RAD9A in Primary Fibroblasts of Individuals with Childhood and Independent Second Cancer}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-74777}, year = {2011}, abstract = {Background: The etiology of secondary cancer in childhood cancer survivors is largely unclear. Exposure of normal somatic cells to radiation and/or chemotherapy can damage DNA and if not all DNA lesions are properly fixed, the mis-repair may lead to pathological consequences. It is plausible to assume that genetic differences, i.e. in the pathways responsible for cell cycle control and DNA repair, play a critical role in the development of secondary cancer. Methodology/Findings: To identify factors that may influence the susceptibility for second cancer formation, we recruited 20 individuals who survived a childhood malignancy and then developed a second cancer as well as 20 carefully matched control individuals with childhood malignancy but without a second cancer. By antibody microarrays, we screened primary fibroblasts of matched patients for differences in the amount of representative DNA repair-associated proteins. We found constitutively decreased levels of RAD9A and several other DNA repair proteins in two-cancer patients, compared to onecancer patients. The RAD9A protein level increased in response to DNA damage, however to a lesser extent in the twocancer patients. Quantification of mRNA expression by real-time RT PCR revealed lower RAD9A mRNA levels in both untreated and 1 Gy c-irradiated cells of two-cancer patients. Conclusions/Significance: Collectively, our results support the idea that modulation of RAD9A and other cell cycle arrest and DNA repair proteins contribute to the risk of developing a second malignancy in childhood cancer patients.}, subject = {Medizin}, language = {en} } @article{GaletzkaHansmannElHajjetal.2012, author = {Galetzka, Danuta and Hansmann, Tamara and El Hajj, Nady and Weis, Eva and Irmscher, Benjamin and Ludwig, Marco and Schneider-R{\"a}tzke, Brigitte and Kohlschmidt, Nicolai and Beyer, Vera and Bartsch, Oliver and Zechner, Ulrich and Spix, Claudia and Haaf, Thomas}, title = {Monozygotic twins discordant for constitutive BRCA1 promoter methylation, childhood cancer and secondary cancer}, series = {Epigenetics}, volume = {7}, journal = {Epigenetics}, number = {1}, doi = {10.4161/epi.7.1.18814}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125386}, pages = {47-54}, year = {2012}, abstract = {We describe monozygotic twins discordant for childhood leukemia and secondary thyroid carcinoma. We used bisulfite pyrosequencing to compare the constitutive promoter methylation of BRCA1 and several other tumor suppressor genes in primary fibroblasts. The affected twin displayed an increased BRCA1 methylation (12\%), compared with her sister (3\%). Subsequent bisulfite plasmid sequencing demonstrated that 13\% (6 of 47) BRCA1 alleles were fully methylated in the affected twin, whereas her sister displayed only single CpG errors without functional implications. This between-twin methylation difference was also found in irradiated fibroblasts and untreated saliva cells. The BRCA1 epimutation may have originated by an early somatic event in the affected twin: approximately 25\% of her body cells derived from different embryonic cell lineages carry one epigenetically inactivated BRCA1 allele. This epimutation was associated with reduced basal protein levels and a higher induction of BRCA1 after DNA damage. In addition, we performed a genome-wide microarray analysis of both sisters and found several copy number variations, i.e., heterozygous deletion and reduced expression of the RSPO3 gene in the affected twin. This monozygotic twin pair represents an impressive example of epigenetic somatic mosaicism, suggesting a role for constitutive epimutations, maybe along with de novo genetic alterations in recurrent tumor development.}, language = {en} } @article{HansmannPliushchLeubneretal.2012, author = {Hansmann, Tamara and Pliushch, Galyna and Leubner, Monika and Kroll, Patricia and Endt, Daniela and Gehrig, Andrea and Preisler-Adams, Sabine and Wieacker, Peter and Haaf, Thomas}, title = {Constitutive promoter methylation of BRCA1 and RAD51C in patients with familial ovarian cancer and early-onset sporadic breast cancer}, series = {Human Molecular Genetics}, volume = {21}, journal = {Human Molecular Genetics}, number = {21}, doi = {10.1093/hmg/dds308}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125673}, pages = {4669-4679}, year = {2012}, abstract = {Genetic defects in breast cancer (BC) susceptibility genes, most importantly BRCA1 and BRCA2, account for ∼40\% of hereditary BC and ovarian cancer (OC). Little is known about the contribution of constitutive (soma-wide) epimutations to the remaining cases. We developed bisulfite pyrosequencing assays to screen >600 affected BRCA1/BRCA2 mutation-negative patients from the German Consortium for Hereditary Breast and Ovarian Cancer for constitutive hypermethylation of ATM, BRCA1, BRCA2, RAD51C, PTEN and TP53 in blood cells. In a second step, patients with ≥6\% promoter methylation were analyzed by bisulfite plasmid sequencing to demonstrate the presence of hypermethylated alleles (epimutations), indicative of epigenetic gene silencing. Altogether we identified nine (1.4\%) patients with constitutive BRCA1 and three (0.5\%) with RAD51C hypermethylation. Epimutations were found in both sporadic cases, in particular in 2 (5.5\%) of 37 patients with early-onset BC, and familial cases, in particular 4 (10\%) of 39 patients with OC. Hypermethylation was always confined to one of the two parental alleles in a subset (12-40\%) of the analyzed cells. Because epimutations occurred in cell types from different embryonal layers, they most likely originated in single cells during early somatic development. We propose that analogous to germline genetic mutations constitutive epimutations may serve as the first hit of tumor development. Because the role of constitutive epimutations in cancer development is likely to be largely underestimated, future strategies for effective testing of susceptibility to BC and OC should include an epimutation screen.}, language = {en} } @article{LehnenZechnerHaaf2013, author = {Lehnen, Harald and Zechner, Urlich and Haaf, Thomas}, title = {Epigenetics of gestational diabetes mellitus and offspring health: the time for action is in early stages of life}, series = {Molecular Human Reproduction}, volume = {19}, journal = {Molecular Human Reproduction}, number = {7}, doi = {10.1093/molehr/gat020}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132165}, pages = {415-422}, year = {2013}, abstract = {The epidemic increase of type 2 diabetes and obesity in developed countries cannot be explained by overnutrition, physical inactivity and/or genetic factors alone. Epidemiologic evidence suggests that an adverse intrauterine environment, in particular a shortage or excess of nutrients is associated with increased risks for many complex diseases later in life. An impressive example for the 'fetal origins of adult disease' is gestational diabetes mellitus which usually presents in 1\% to >10\% of third trimester pregnancies. Intrauterine hyperglycemia is not only associated with increased perinatal morbidity and mortality, but also with increased lifelong risks of the exposed offspring for obesity, metabolic, cardiovascular and malignant diseases. Accumulating evidence suggests that fetal overnutrition (and similarly undernutrition) lead to persistent epigenetic changes in developmentally important genes, influencing neuroendocrine functions, energy homeostasis and metabolism. The concept of fetal programming has important implications for reproductive medicine. Because during early development the epigenome is much more vulnerable to environmental cues than later in life, avoiding adverse environmental factors in the periconceptional and intrauterine period may be much more important for the prevention of adult disease than any (i.e. dietetic) measures in infants and adults. A successful pregnancy should not primarily be defined by the outcome at birth but also by the health status in later life.}, language = {en} } @article{HaafVonaNandaetal.2014, author = {Haaf, Thomas and Vona, Barbara and Nanda, Indrajit and Neuner, Cordula and Schr{\"o}der, J{\"o}rg and Kalscheuer, Vera M. and Shehata-Dieler, Wafaa}, title = {Terminal chromosome 4q deletion syndrome in an infant with hearing impairment and moderate syndromic features: review of literature}, doi = {10.1186/1471-2350-15-72}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110540}, year = {2014}, abstract = {Background Terminal deletions of chromosome 4q are associated with a broad spectrum of phenotypes including cardiac, craniofacial, digital, and cognitive impairment. The rarity of this syndrome renders genotype-phenotype correlation difficult, which is further complicated by the widely different phenotypes observed in patients sharing similar deletion intervals. Case presentation Herein, we describe a boy with congenital hearing impairment and a variety of moderate syndromic features that prompted SNP array analysis disclosing a heterozygous 6.9 Mb deletion in the 4q35.1q35.2 region, which emerged de novo in the maternal germ line. Conclusion In addition to the index patient, we review 35 cases from the literature and DECIPHER database to attempt genotype-phenotype correlations for a syndrome with great phenotypic variability. We delineate intervals with recurrent phenotypic overlap, particularly for cleft palate, congenital heart defect, intellectual disability, and autism spectrum disorder. Broad phenotypic presentation of the terminal 4q deletion syndrome is consistent with incomplete penetrance of the individual symptoms.}, language = {en} } @article{BahenaDaftarianMaroofianetal.2022, author = {Bahena, Paulina and Daftarian, Narsis and Maroofian, Reza and Linares, Paola and Villalobos, Daniel and Mirrahimi, Mehraban and Rad, Aboulfazl and Doll, Julia and Hofrichter, Michaela A. H. and Koparir, Asuman and R{\"o}der, Tabea and Han, Seungbin and Sabbaghi, Hamideh and Ahmadieh, Hamid and Behboudi, Hassan and Villanueva-Mendoza, Cristina and Cort{\´e}s-Gonzalez, Vianney and Zamora-Ortiz, Rocio and Kohl, Susanne and Kuehlewein, Laura and Darvish, Hossein and Alehabib, Elham and La Arenas-Sordo, Maria de Luz and Suri, Fatemeh and Vona, Barbara and Haaf, Thomas}, title = {Unraveling the genetic complexities of combined retinal dystrophy and hearing impairment}, series = {Human Genetics}, volume = {141}, journal = {Human Genetics}, number = {3-4}, issn = {1432-1203}, doi = {10.1007/s00439-021-02303-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267750}, pages = {785-803}, year = {2022}, abstract = {Usher syndrome, the most prevalent cause of combined hereditary vision and hearing impairment, is clinically and genetically heterogeneous. Moreover, several conditions with phenotypes overlapping Usher syndrome have been described. This makes the molecular diagnosis of hereditary deaf-blindness challenging. Here, we performed exome sequencing and analysis on 7 Mexican and 52 Iranian probands with combined retinal degeneration and hearing impairment (without intellectual disability). Clinical assessment involved ophthalmological examination and hearing loss questionnaire. Usher syndrome, most frequently due to biallelic variants in MYO7A (USH1B in 16 probands), USH2A (17 probands), and ADGRV1 (USH2C in 7 probands), was diagnosed in 44 of 59 (75\%) unrelated probands. Almost half of the identified variants were novel. Nine of 59 (15\%) probands displayed other genetic entities with dual sensory impairment, including Alstr{\"o}m syndrome (3 patients), cone-rod dystrophy and hearing loss 1 (2 probands), and Heimler syndrome (1 patient). Unexpected findings included one proband each with Scheie syndrome, coenzyme Q10 deficiency, and pseudoxanthoma elasticum. In four probands, including three Usher cases, dual sensory impairment was either modified/aggravated or caused by variants in distinct genes associated with retinal degeneration and/or hearing loss. The overall diagnostic yield of whole exome analysis in our deaf-blind cohort was 92\%. Two (3\%) probands were partially solved and only 3 (5\%) remained without any molecular diagnosis. In many cases, the molecular diagnosis is important to guide genetic counseling, to support prognostic outcomes and decisions with currently available and evolving treatment modalities.}, language = {en} }