@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{DollVonaSchnappetal.2020, author = {Doll, Julia and Vona, Barbara and Schnapp, Linda and R{\"u}schendorf, Franz and Khan, Imran and Khan, Saadullah and Muhammad, Noor and Alam Khan, Sher and Nawaz, Hamed and Khan, Ajmal and Ahmad, Naseer and Kolb, Susanne M. and K{\"u}hlewein, Laura and Labonne, Jonathan D. J. and Layman, Lawrence C. and Hofrichter, Michaela A. H. and R{\"o}der, Tabea and Dittrich, Marcus and M{\"u}ller, Tobias and Graves, Tyler D. and Kong, Il-Keun and Nanda, Indrajit and Kim, Hyung-Goo and Haaf, Thomas}, title = {Genetic Spectrum of Syndromic and Non-Syndromic Hearing Loss in Pakistani Families}, series = {Genes}, volume = {11}, journal = {Genes}, number = {11}, issn = {2073-4425}, doi = {10.3390/genes11111329}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219293}, year = {2020}, abstract = {The current molecular genetic diagnostic rates for hereditary hearing loss (HL) vary considerably according to the population background. Pakistan and other countries with high rates of consanguineous marriages have served as a unique resource for studying rare and novel forms of recessive HL. A combined exome sequencing, bioinformatics analysis, and gene mapping approach for 21 consanguineous Pakistani families revealed 13 pathogenic or likely pathogenic variants in the genes GJB2, MYO7A, FGF3, CDC14A, SLITRK6, CDH23, and MYO15A, with an overall resolve rate of 61.9\%. GJB2 and MYO7A were the most frequently involved genes in this cohort. All the identified variants were either homozygous or compound heterozygous, with two of them not previously described in the literature (15.4\%). Overall, seven missense variants (53.8\%), three nonsense variants (23.1\%), two frameshift variants (15.4\%), and one splice-site variant (7.7\%) were observed. Syndromic HL was identified in five (23.8\%) of the 21 families studied. This study reflects the extreme genetic heterogeneity observed in HL and expands the spectrum of variants in deafness-associated genes.}, language = {en} } @article{LekszasNandaVonaetal.2019, author = {Lekszas, Caroline and Nanda, Indrajit and Vona, Barbara and B{\"o}ck, Julia and Ashrafzadeh, Farah and Donyadideh, Nahid and Ebrahimzadeh, Farnoosh and Ahangari, Najmeh and Maroofian, Reza and Karimiani, Ehsan Ghayoor and Haaf, Thomas}, title = {Unbalanced segregation of a paternal t(9;11)(p24.3;p15.4) translocation causing familial Beckwith-Wiedemann syndrome: a case report}, series = {BMC Medical Genomics}, volume = {12}, journal = {BMC Medical Genomics}, doi = {10.1186/s12920-019-0539-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200422}, pages = {83}, year = {2019}, abstract = {Background The vast majority of cases with Beckwith-Wiedemann syndrome (BWS) are caused by a molecular defect in the imprinted chromosome region 11p15.5. The underlying mechanisms include epimutations, uniparental disomy, copy number variations, and structural rearrangements. In addition, maternal loss-of-function mutations in CDKN1C are found. Despite growing knowledge on BWS pathogenesis, up to 20\% of patients with BWS phenotype remain without molecular diagnosis. Case presentation Herein, we report an Iranian family with two females affected with BWS in different generations. Bisulfite pyrosequencing revealed hypermethylation of the H19/IGF2: intergenic differentially methylated region (IG DMR), also known as imprinting center 1 (IC1) and hypomethylation of the KCNQ1OT1: transcriptional start site (TSS) DMR (IC2). Array CGH demonstrated an 8 Mb duplication on chromosome 11p15.5p15.4 (205,827-8,150,933) and a 1 Mb deletion on chromosome 9p24.3 (209,020-1,288,114). Chromosome painting revealed that this duplication-deficiency in both patients is due to unbalanced segregation of a paternal reciprocal t(9;11)(p24.3;p15.4) translocation. Conclusions This is the first report of a paternally inherited unbalanced translocation between the chromosome 9 and 11 short arms underlying familial BWS. Copy number variations involving the 11p15.5 region are detected by the consensus diagnostic algorithm. However, in complex cases which do not only affect the BWS region itself, characterization of submicroscopic chromosome rearrangements can assist to estimate the recurrence risk and possible phenotypic outcomes.}, language = {en} } @article{VonaNandaShehataDieleretal.2017, author = {Vona, Barbara and Nanda, Indrajit and Shehata-Dieler, Wafaa and Haaf, Thomas}, title = {Genetics of Tinnitus: Still in its Infancy}, series = {Frontiers in Neuroscience}, volume = {11}, journal = {Frontiers in Neuroscience}, number = {236}, doi = {10.3389/fnins.2017.00236}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170926}, year = {2017}, abstract = {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.}, language = {en} } @article{VonaHofrichterSchroederetal.2018, author = {Vona, Barbara and Hofrichter, Michaela A. H. and Schr{\"o}der, J{\"o}rg and Shehata-Dieler, Wafaa and Nanda, Indrajit and Haaf, Thomas}, title = {Hereditary hearing loss SNP-microarray pilot study}, series = {BMC Research Notes}, volume = {11}, journal = {BMC Research Notes}, number = {391}, doi = {10.1186/s13104-018-3466-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176239}, year = {2018}, abstract = {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.}, language = {en} }