@article{EngertDollVonaetal.2023, author = {Engert, Jonas and Doll, Julia and Vona, Barbara and Ehret Kasemo, Totta and Spahn, Bjoern and Hagen, Rudolf and Rak, Kristen and Voelker, Johannes}, title = {mRNA abundance of neurogenic factors correlates with hearing capacity in auditory brainstem nuclei of the rat}, series = {Life}, volume = {13}, journal = {Life}, number = {9}, issn = {2075-1729}, doi = {10.3390/life13091858}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357392}, year = {2023}, abstract = {Neural stem cells (NSCs) have previously been described up to the adult stage in the rat cochlear nucleus (CN). A decreasing neurogenic potential was observed with critical changes around hearing onset. A better understanding of molecular factors affecting NSCs and neurogenesis is of interest as they represent potential targets to treat the cause of neurologically based hearing disorders. The role of genes affecting NSC development and neurogenesis in CN over time on hearing capacity has remained unclear. This study investigated the mRNA abundance of genes influencing NSCs and neurogenesis in rats' CN over time. The CN of rats on postnatal days 6, 12, and 24 were examined. Real-time quantitative polymerase chain reaction arrays were used to compare mRNA levels of 84 genes relevant to NSCs and neurogenesis. Age- and hearing-specific patterns of changes in mRNA abundance of neurogenically relevant genes were detected in the rat CN. Additionally, crucial neurogenic factors with significant and relevant influence on neurogenesis were identified. The results of this work should contribute to a better understanding of the molecular mechanisms underlying the neurogenesis of the auditory pathway.}, language = {en} } @article{DollKolbSchnappetal.2020, author = {Doll, Julia and Kolb, Susanne and Schnapp, Linda and Rad, Aboulfazl and R{\"u}schendorf, Franz and Khan, Imran and Adli, Abolfazl and Hasanzadeh, Atefeh and Liedtke, Daniel and Knaup, Sabine and Hofrichter, Michaela AH and M{\"u}ller, Tobias and Dittrich, Marcus and Kong, Il-Keun and Kim, Hyung-Goo and Haaf, Thomas and Vona, Barbara}, title = {Novel loss-of-function variants in CDC14A are associated with recessive sensorineural hearing loss in Iranian and Pakistani patients}, series = {International Journal of Molecular Sciences}, volume = {21}, journal = {International Journal of Molecular Sciences}, number = {1}, issn = {1422-0067}, doi = {10.3390/ijms21010311}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285142}, year = {2020}, abstract = {CDC14A encodes the Cell Division Cycle 14A protein and has been associated with autosomal recessive non-syndromic hearing loss (DFNB32), as well as hearing impairment and infertile male syndrome (HIIMS) since 2016. To date, only nine variants have been associated in patients whose initial symptoms included moderate-to-profound hearing impairment. Exome analysis of Iranian and Pakistani probands who both showed bilateral, sensorineural hearing loss revealed a novel splice site variant (c.1421+2T>C, p.?) that disrupts the splice donor site and a novel frameshift variant (c.1041dup, p.Ser348Glnfs*2) in the gene CDC14A, respectively. To evaluate the pathogenicity of both loss-of-function variants, we analyzed the effects of both variants on the RNA-level. The splice variant was characterized using a minigene assay. Altered expression levels due to the c.1041dup variant were assessed using RT-qPCR. In summary, cDNA analysis confirmed that the c.1421+2T>C variant activates a cryptic splice site, resulting in a truncated transcript (c.1414_1421del, p.Val472Leufs*20) and the c.1041dup variant results in a defective transcript that is likely degraded by nonsense-mediated mRNA decay. The present study functionally characterizes two variants and provides further confirmatory evidence that CDC14A is associated with a rare form of hereditary hearing loss.}, 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} } @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{HofrichterMojaradDolletal.2018, author = {Hofrichter, Michaela A. H. and Mojarad, Majid and Doll, Julia and Grimm, Clemens and Eslahi, Atiye and Hosseini, Neda Sadat and Rajati, Mohsen and M{\"u}ller, Tobias and Dittrich, Marcus and Maroofian, Reza and Haaf, Thomas and Vona, Barbara}, title = {The conserved p.Arg108 residue in S1PR2 (DFNB68) is fundamental for proper hearing: evidence from a consanguineous Iranian family}, series = {BMC Medical Genetics}, volume = {19}, journal = {BMC Medical Genetics}, number = {81}, doi = {10.1186/s12881-018-0598-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175755}, year = {2018}, abstract = {Background: Genetic heterogeneity and consanguineous marriages make recessive inherited hearing loss in Iran the second most common genetic disorder. Only two reported pathogenic variants (c.323G>C, p.Arg108Pro and c.419A>G, p.Tyr140Cys) in the S1PR2 gene have previously been linked to autosomal recessive hearing loss (DFNB68) in two Pakistani families. We describe a segregating novel homozygous c.323G>A, p.Arg108Gln pathogenic variant in S1PR2 that was identified in four affected individuals from a consanguineous five generation Iranian family. Methods: Whole exome sequencing and bioinformatics analysis of 116 hearing loss-associated genes was performed in an affected individual from a five generation Iranian family. Segregation analysis and 3D protein modeling of the p.Arg108 exchange was performed. Results: The two Pakistani families previously identified with S1PR2 pathogenic variants presented profound hearing loss that is also observed in the affected Iranian individuals described in the current study. Interestingly, we confirmed mixed hearing loss in one affected individual. 3D protein modeling suggests that the p.Arg108 position plays a key role in ligand receptor interaction, which is disturbed by the p.Arg108Gln change. Conclusion: In summary, we report the third overall mutation in S1PR2 and the first report outside the Pakistani population. Furthermore, we describe a novel variant that causes an amino acid exchange (p.Arg108Gln) in the same amino acid residue as one of the previously reported Pakistani families (p.Arg108Pro). This finding emphasizes the importance of the p.Arg108 amino acid in normal hearing and confirms and consolidates the role of S1PR2 in autosomal recessive hearing loss.}, language = {en} }