TY - JOUR A1 - Weis, Eva A1 - Schoen, Holger A1 - Victor, Anja A1 - Spix, Claudia A1 - Ludwig, Marco A1 - Schneider-Raetzke, Brigitte A1 - Kohlschmidt, Nicolai A1 - Bartsch, Oliver A1 - Gerhold-Ay, Aslihan A1 - Boehm, Nils A1 - Grus, Franz A1 - Haaf, Thomas A1 - Galetzka, Danuta T1 - Reduced mRNA and Protein Expression of the Genomic Caretaker RAD9A in Primary Fibroblasts of Individuals with Childhood and Independent Second Cancer JF - PLoS ONE N2 - 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. KW - DNA methylation KW - Malignant neoplasms KW - Genes KW - Instability KW - Stability KW - Susceptibility KW - Checkpoints KW - Repair KW - Damage Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-141838 VL - 6 IS - 10 ER - TY - JOUR A1 - Weis, Eva A1 - Schoen, Holger A1 - Victor, Anja A1 - Spix, Claudia A1 - Ludwig, Marco A1 - Schneider-Raetzke, Brigitte A1 - Kohlschmidt, Nicolai A1 - Bartsch, Oliver A1 - Gerhold-Ay, Aslihan A1 - Boehm, Nils A1 - Grus, Franz A1 - Haaf, Thomas A1 - Galetzka, Danuta T1 - Reduced mRNA and Protein Expression of the Genomic Caretaker RAD9A in Primary Fibroblasts of Individuals with Childhood and Independent Second Cancer N2 - 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. KW - Medizin Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-74777 ER - TY - JOUR A1 - Vona, Barbara A1 - Nanda, Indrajit A1 - Shehata-Dieler, Wafaa A1 - Haaf, Thomas T1 - Genetics of Tinnitus: Still in its Infancy JF - Frontiers in Neuroscience N2 - Tinnitus is the perception of a phantom sound that affects between 10 and 15% of the general population. Despite this considerable prevalence, treatments for tinnitus are presently lacking. Tinnitus exhibits a diverse array of recognized risk factors and extreme clinical heterogeneity. Furthermore, it can involve an unknown number of auditory and non-auditory networks and molecular pathways. This complex combination has hampered advancements in the field. The identification of specific genetic factors has been at the forefront of several research investigations in the past decade. Nine studies have examined genes in a case-control association approach. Recently, a genome-wide association study has highlighted several potentially significant pathways that are implicated in tinnitus. Two twin studies have calculated a moderate heritability for tinnitus and disclosed a greater concordance rate in monozygotic twins compared to dizygotic twins. Despite the more recent data alluding to genetic factors in tinnitus, a strong association with any specific genetic locus is lacking and a genetic study with sufficient statistical power has yet to be designed. Future research endeavors must overcome the many inherent limitations in previous study designs. This review summarizes the previously embarked upon tinnitus genetic investigations and summarizes the hurdles that have been encountered. The identification of candidate genes responsible for tinnitus may afford gene based diagnostic approaches, effective therapy development, and personalized therapeutic intervention. KW - twin study KW - complex disorders KW - genetics KW - genetic heterogeneity KW - genome-wide association study (GWAS) KW - hearing loss KW - tinnitus Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170926 VL - 11 IS - 236 ER - TY - JOUR A1 - Vona, Barbara A1 - Mazaheri, Neda A1 - Lin, Sheng-Jia A1 - Dunbar, Lucy A. A1 - Maroofian, Reza A1 - Azaiez, Hela A1 - Booth, Kevin T. A1 - Vitry, Sandrine A1 - Rad, Aboulfazl A1 - Rüschendorf, Franz A1 - Varshney, Pratishtha A1 - Fowler, Ben A1 - Beetz, Christian A1 - Alagramam, Kumar N. A1 - Murphy, David A1 - Shariati, Gholamreza A1 - Sedaghat, Alireza A1 - Houlden, Henry A1 - Petree, Cassidy A1 - VijayKumar, Shruthi A1 - Smith, Richard J. H. A1 - Haaf, Thomas A1 - El-Amraoui, Aziz A1 - Bowl, Michael R. A1 - Varshney, Gaurav K. A1 - Galehdari, Hamid T1 - A biallelic variant in CLRN2 causes non-syndromic hearing loss in humans JF - Human Genetics N2 - Deafness, the most frequent sensory deficit in humans, is extremely heterogeneous with hundreds of genes involved. Clinical and genetic analyses of an extended consanguineous family with pre-lingual, moderate-to-profound autosomal recessive sensorineural hearing loss, allowed us to identify CLRN2, encoding a tetraspan protein, as a new deafness gene. Homozygosity mapping followed by exome sequencing identified a 14.96 Mb locus on chromosome 4p15.32p15.1 containing a likely pathogenic missense variant in CLRN2 (c.494C > A, NM_001079827.2) segregating with the disease. Using in vitro RNA splicing analysis, we show that the CLRN2 c.494C > A variant leads to two events: (1) the substitution of a highly conserved threonine (uncharged amino acid) to lysine (charged amino acid) at position 165, p.(Thr165Lys), and (2) aberrant splicing, with the retention of intron 2 resulting in a stop codon after 26 additional amino acids, p.(Gly146Lysfs*26). Expression studies and phenotyping of newly produced zebrafish and mouse models deficient for clarin 2 further confirm that clarin 2, expressed in the inner ear hair cells, is essential for normal organization and maintenance of the auditory hair bundles, and for hearing function. Together, our findings identify CLRN2 as a new deafness gene, which will impact future diagnosis and treatment for deaf patients. KW - deafness KW - CLRN2 KW - gene Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267740 SN - 1432-1203 VL - 140 IS - 6 ER - TY - JOUR A1 - Vona, Barbara A1 - Maroofian, Reza A1 - Bellacchio, Emanuele A1 - Najafi, Maryam A1 - Thompson, Kyle A1 - Alahmad, Ahmad A1 - He, Langping A1 - Ahangari, Najmeh A1 - Rad, Abolfazl A1 - Shahrokhzadeh, Sima A1 - Bahena, Paulina A1 - Mittag, Falk A1 - Traub, Frank A1 - Movaffagh, Jebrail A1 - Amiri, Nafise A1 - Doosti, Mohammad A1 - Boostani, Reza A1 - Shirzadeh, Ebrahim A1 - Haaf, Thomas A1 - Diodato, Daria A1 - Schmidts, Miriam A1 - Taylor, Robert W. A1 - Karimiani, Ehsan Ghayoor T1 - Expanding the clinical phenotype of IARS2-related mitochondrial disease JF - BMC Medical Genetics N2 - Background: IARS2 encodes a mitochondrial isoleucyl-tRNA synthetase, a highly conserved nuclear-encoded enzyme required for the charging of tRNAs with their cognate amino acid for translation. Recently, pathogenic IARS2 variants have been identified in a number of patients presenting broad clinical phenotypes with autosomal recessive inheritance. These phenotypes range from Leigh and West syndrome to a new syndrome abbreviated CAGSSS that is characterised by cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia, as well as cataract with no additional anomalies. Methods: Genomic DNA from Iranian probands from two families with consanguineous parental background and overlapping CAGSSS features were subjected to exome sequencing and bioinformatics analysis. Results: Exome sequencing and data analysis revealed a novel homozygous missense variant (c.2625C > T, p.Pro909Ser, NM_018060.3) within a 14.3 Mb run of homozygosity in proband 1 and a novel homozygous missense variant (c.2282A > G, p.His761Arg) residing in an ~ 8 Mb region of homozygosity in a proband of the second family. Patient-derived fibroblasts from proband 1 showed normal respiratory chain enzyme activity, as well as unchanged oxidative phosphorylation protein subunits and IARS2 levels. Homology modelling of the known and novel amino acid residue substitutions in IARS2 provided insight into the possible consequence of these variants on function and structure of the protein. Conclusions: This study further expands the phenotypic spectrum of IARS2 pathogenic variants to include two patients (patients 2 and 3) with cataract and skeletal dysplasia and no other features of CAGSSS to the possible presentation of the defects in IARS2. Additionally, this study suggests that adult patients with CAGSSS may manifest central adrenal insufficiency and type II esophageal achalasia and proposes that a variable sensorineural hearing loss onset, proportionate short stature, polyneuropathy, and mild dysmorphic features are possible, as seen in patient 1. Our findings support that even though biallelic IARS2 pathogenic variants can result in a distinctive, clinically recognisable phenotype in humans, it can also show a wide range of clinical presentation from severe pediatric neurological disorders of Leigh and West syndrome to both non-syndromic cataract and cataract accompanied by skeletal dysplasia. KW - adrenal insufficiency KW - CAGSSS KW - cataracts KW - growth hormone deficiency KW - IARS2 KW - sensory neuropathy KW - sensorineural hearing loss KW - type II esophageal achalasia KW - skeletal dysplasia Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176620 VL - 19 IS - 196 ER - TY - JOUR A1 - Vona, Barbara A1 - Hofrichter, Michaela A. H. A1 - Schröder, Jörg A1 - Shehata-Dieler, Wafaa A1 - Nanda, Indrajit A1 - Haaf, Thomas T1 - Hereditary hearing loss SNP-microarray pilot study JF - BMC Research Notes N2 - Objectives: Despite recent advancements in diagnostic tools, the genomic landscape of hereditary hearing loss remains largely uncharacterized. One strategy to understand genome-wide aberrations includes the analysis of copy number variation that can be mapped using SNP-microarray technology. A growing collection of literature has begun to uncover the importance of copy number variation in hereditary hearing loss. This pilot study underpins a larger effort that involves the stage-wise analysis of hearing loss patients, many of whom have advanced to high-throughput sequencing analysis. Data description: Our data originate from the Infinium HumanOmni1-Quad v1.0 SNP-microarrays (Illumina) that provide useful markers for genome-wide association studies and copy number variation analysis. This dataset comprises a cohort of 108 individuals (99 with hearing loss, 9 normal hearing family members) for the purpose of understanding the genetic contribution of copy number variations to hereditary hearing loss. These anonymized SNP-microarray data have been uploaded to the NCBI Gene Expression Omnibus and are intended to benefit other investigators interested in aggregating platform-matched array patient datasets or as part of a supporting reference tool for other laboratories to better understand recurring copy number variations in other genetic disorders. KW - copy number variation KW - genotyping arrays KW - hereditary hearing loss KW - illumina KW - infinium HumanOmni1-Quad KW - SNP-microarray Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176239 VL - 11 IS - 391 ER - TY - JOUR A1 - Schneider, Eberhard A1 - Pliushch, Galyna A1 - El Hajj, Nady A1 - Galetzka, Danuta A1 - Puhl, Alexander A1 - Schorsch, Martin A1 - Frauenknecht, Katrin A1 - Riepert, Thomas A1 - Tresch, Achim A1 - Mueller, Annette M. A1 - Coerdt, Wiltrud A1 - Zechner, Ulrich A1 - Haaf, Thomas T1 - Spatial, temporal and interindividual epigenetic variation of functionally important DNA methylation patterns N2 - 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. KW - Medizin Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68371 ER - TY - JOUR A1 - Schneider, Eberhard A1 - El Hajj, Nady A1 - Müller, Fabian A1 - Navarro, Bianca A1 - Haaf, Thomas T1 - Epigenetic Dysregulation in the Prefrontal Cortex of Suicide Completers JF - Cytogenetic and Genome Research N2 - 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. KW - Cortex KW - DNA methylation KW - Suicidal behavior KW - Transcription regulation Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199032 SN - 1424-8581 SN - 1424-859X VL - 146 IS - 1 ER - TY - JOUR A1 - Schneider, Eberhard A1 - El Hajj, Nady A1 - Haaf, Thomas T1 - Epigenetic Information from Ancient DNA Provides New Insights into Human Evolution BT - Commentary on Gokhman D et al. (2014): Reconstructing the DNA Methylation Maps of the Neanderthal and the Denisovan. Science 344:523–527 JF - Brain, Behavior and Evolution N2 - No abstract available. KW - human evolution KW - Neanderthal Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-196800 SN - 0006-8977 SN - 1421-9743 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 84 IS - 3 ER - TY - JOUR A1 - Schneider, Eberhard A1 - Dittrich, Marcus A1 - Böck, Julia A1 - Nanda, Indrajit A1 - Müller, Tobias A1 - Seidmann, Larissa A1 - Tralau, Tim A1 - Galetzka, Danuta A1 - El Hajj, Nady A1 - Haaf, Thomas T1 - CpG sites with continuously increasing or decreasing methylation from early to late human fetal brain development JF - Gene N2 - 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. KW - Autism spectrum disorders KW - DNA methylation KW - Genome KW - Autism KW - Frontal cortex KW - Human prefrontal cortex KW - Gene-expression KW - Schizophrenia KW - Patterns KW - Transcription KW - Epigenetics KW - Environment KW - Fetal brain development KW - DNA methylation dynamics KW - Methylome Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-186936 VL - 592 IS - 1 ER -