@article{VonaMazaheriLinetal.2021, author = {Vona, Barbara and Mazaheri, Neda and Lin, Sheng-Jia and Dunbar, Lucy A. and Maroofian, Reza and Azaiez, Hela and Booth, Kevin T. and Vitry, Sandrine and Rad, Aboulfazl and R{\"u}schendorf, Franz and Varshney, Pratishtha and Fowler, Ben and Beetz, Christian and Alagramam, Kumar N. and Murphy, David and Shariati, Gholamreza and Sedaghat, Alireza and Houlden, Henry and Petree, Cassidy and VijayKumar, Shruthi and Smith, Richard J. H. and Haaf, Thomas and El-Amraoui, Aziz and Bowl, Michael R. and Varshney, Gaurav K. and Galehdari, Hamid}, title = {A biallelic variant in CLRN2 causes non-syndromic hearing loss in humans}, series = {Human Genetics}, volume = {140}, journal = {Human Genetics}, number = {6}, issn = {1432-1203}, doi = {10.1007/s00439-020-02254-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267740}, pages = {915-931}, year = {2021}, abstract = {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.}, language = {en} } @article{MajounieRentonMoketal.2012, author = {Majounie, Elisa and Renton, Alan E. and Mok, Kin and Dopper, Elise G. P. and Waite, Adrian and Rollinson, Sara and Chi{\`o}, Adriano and Restagno, Gabriella and Nicolaou, Nayia and Simon-Sanchez, Javier and van Swieten, John C. and Abramzon, Yevgeniya and Johnson, Janel O. and Sendtner, Michael and Pamphlett, Roger and Orrell, Richard W. and Mead, Simon and Sidle, Katie C. and Houlden, Henry and Rohrer, Jonathan D. and Morrison, Karen E. and Pall, Hardev and Talbot, Kevin and Ansorge, Olaf and Hernandez, Dena G. and Arepalli, Sampath and Sabatelli, Mario and Mora, Gabriele and Corbo, Massimo and Giannini, Fabio and Calvo, Andrea and Englund, Elisabet and Borghero, Giuseppe and Floris, Gian Luca and Remes, Anne M. and Laaksovirta, Hannu and McCluskey, Leo and Trojanowski, John Q. and Van Deerlin, Vivianna M. and Schellenberg, Gerard D. and Nalls, Michael A. and Drory, Vivian E. and Lu, Chin-Song and Yeh, Tu-Hsueh and Ishiura, Hiroyuki and Takahashi, Yuji and Tsuji, Shoji and Le Ber, Isabelle and Brice, Alexis and Drepper, Carsten and Williams, Nigel and Kirby, Janine and Shaw, Pamela and Hardy, John and Tienari, Pentti J. and Heutink, Peter and Morris, Huw R. and Pickering-Brown, Stuart and Traynor, Bryan J.}, title = {Frequency of the C9orf72 hexanucleotide repeat expansion in patients with amyotrophic lateral sclerosis and frontotemporal dementia: a cross-sectional study}, series = {The Lancet Neurology}, volume = {11}, journal = {The Lancet Neurology}, doi = {10.1016/S1474-4422(12)70043-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-154644}, pages = {323 -- 330}, year = {2012}, abstract = {Background We aimed to accurately estimate the frequency of a hexanucleotide repeat expansion in C9orf72 that has been associated with a large proportion of cases of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Methods We screened 4448 patients diagnosed with ALS (El Escorial criteria) and 1425 patients with FTD (Lund-Manchester criteria) from 17 regions worldwide for the GGGGCC hexanucleotide expansion using a repeat-primed PCR assay. We assessed familial disease status on the basis of self-reported family history of similar neurodegenerative diseases at the time of sample collection. We compared haplotype data for 262 patients carrying the expansion with the known Finnish founder risk haplotype across the chromosomal locus. We calculated age-related penetrance using the Kaplan-Meier method with data for 603 individuals with the expansion. Findings In patients with sporadic ALS, we identified the repeat expansion in 236 (7·0\%) of 3377 white individuals from the USA, Europe, and Australia, two (4·1\%) of 49 black individuals from the USA, and six (8·3\%) of 72 Hispanic individuals from the USA. The mutation was present in 217 (39·3\%) of 552 white individuals with familial ALS from Europe and the USA. 59 (6·0\%) of 981 white Europeans with sporadic FTD had the mutation, as did 99 (24·8\%) of 400 white Europeans with familial FTD. Data for other ethnic groups were sparse, but we identified one Asian patient with familial ALS (from 20 assessed) and two with familial FTD (from three assessed) who carried the mutation. The mutation was not carried by the three Native Americans or 360 patients from Asia or the Pacific Islands with sporadic ALS who were tested, or by 41 Asian patients with sporadic FTD. All patients with the repeat expansion had (partly or fully) the founder haplotype, suggesting a one-off expansion occurring about 1500 years ago. The pathogenic expansion was non-penetrant in individuals younger than 35 years, 50\% penetrant by 58 years, and almost fully penetrant by 80 years. Interpretation A common Mendelian genetic lesion in C9orf72 is implicated in many cases of sporadic and familial ALS and FTD. Testing for this pathogenic expansion should be considered in the management and genetic counselling of patients with these fatal neurodegenerative diseases.}, language = {en} } @article{MencacciIsaiasReichetal.2014, author = {Mencacci, Niccol{\´o} E. and Isaias, Ioannis U. and Reich, Martin M. and Ganos, Christos and Plagnol, Vincent and Polke, James M. and Bras, Jose and Hersheson, Joshua and Stamelou, Maria and Pittman, Alan M. and Noyce, Alastair J. and Mok, Kin Y. and Opladen, Thomas and Kunstmann, Erdmute and Hodecker, Sybille and M{\"u}nchau, Alexander and Volkmann, Jens and Samnick, Samuel and Sidle, Katie and Nanji, Tina and Sweeney, Mary G. and Houlden, Henry and Batla, Amit and Zecchinelli, Anna L. and Pezzoli, Gianni and Marotta, Giorgio and Lees, Andrew and Alegria, Paulo and Krack, Paul and Cormier-Dequaire, Florence and Lesage, Suzanne and Brice, Alexis and Heutink, Peter and Gasser, Thomas and Lubbe, Steven J. and Morris, Huw R. and Taba, Pille and Koks, Sulev and Majounie, Elisa and Gibbs, J. Raphael and Singleton, Andrew and Hardy, John and Klebe, Stephan and Bhatia, Kailash P. and Wood, Nicholas W.}, title = {Parkinson's disease in GTP cyclohydrolase 1 mutation carriers}, series = {Brain}, volume = {137}, journal = {Brain}, number = {9}, doi = {10.1093/brain/awu179}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121268}, pages = {2480-92}, year = {2014}, abstract = {GTP cyclohydrolase 1, encoded by the GCH1 gene, is an essential enzyme for dopamine production in nigrostriatal cells. Loss-of-function mutations in GCH1 result in severe reduction of dopamine synthesis in nigrostriatal cells and are the most common cause of DOPA-responsive dystonia, a rare disease that classically presents in childhood with generalized dystonia and a dramatic long-lasting response to levodopa. We describe clinical, genetic and nigrostriatal dopaminergic imaging ([(123)I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl) tropane single photon computed tomography) findings of four unrelated pedigrees with DOPA-responsive dystonia in which pathogenic GCH1 variants were identified in family members with adult-onset parkinsonism. Dopamine transporter imaging was abnormal in all parkinsonian patients, indicating Parkinson's disease-like nigrostriatal dopaminergic denervation. We subsequently explored the possibility that pathogenic GCH1 variants could contribute to the risk of developing Parkinson's disease, even in the absence of a family history for DOPA-responsive dystonia. The frequency of GCH1 variants was evaluated in whole-exome sequencing data of 1318 cases with Parkinson's disease and 5935 control subjects. Combining cases and controls, we identified a total of 11 different heterozygous GCH1 variants, all at low frequency. This list includes four pathogenic variants previously associated with DOPA-responsive dystonia (Q110X, V204I, K224R and M230I) and seven of undetermined clinical relevance (Q110E, T112A, A120S, D134G, I154V, R198Q and G217V). The frequency of GCH1 variants was significantly higher (Fisher's exact test P-value 0.0001) in cases (10/1318 = 0.75\%) than in controls (6/5935 = 0.1\%; odds ratio 7.5; 95\% confidence interval 2.4-25.3). Our results show that rare GCH1 variants are associated with an increased risk for Parkinson's disease. These findings expand the clinical and biological relevance of GTP cycloydrolase 1 deficiency, suggesting that it not only leads to biochemical striatal dopamine depletion and DOPA-responsive dystonia, but also predisposes to nigrostriatal cell loss. Further insight into GCH1-associated pathogenetic mechanisms will shed light on the role of dopamine metabolism in nigral degeneration and Parkinson's disease.}, language = {en} }