@article {382, title = {Homozygous Mutations in TBC1D23 Lead to a Non-degenerative Form of Pontocerebellar Hypoplasia.}, journal = {Am J Hum Genet}, volume = {101}, year = {2017}, month = {2017 Sep 07}, pages = {441-450}, abstract = {

Pontocerebellar hypoplasia (PCH) represents a group of recessive developmental disorders characterized by impaired growth of the pons and cerebellum, which frequently follows a degenerative course. Currently, there are 10 partially overlapping clinical subtypes and 13 genes known mutated in PCH. Here, we report biallelic TBC1D23 mutations in six individuals from four unrelated families manifesting a non-degenerative form of PCH. In addition to reduced volume of pons and cerebellum, affected individuals had microcephaly, psychomotor delay, and ataxia. In zebrafish, tbc1d23 morphants replicated the human phenotype showing hindbrain volume loss. TBC1D23 localized at the trans-Golgi and was regulated by the small GTPases Arl1 and Arl8, suggesting a role in trans-Golgi membrane trafficking. Altogether, this study provides a causative link between TBC1D23 mutations and PCH and suggests a less severe clinical course than other PCH subtypes.

}, keywords = {Adolescent, Animals, Cerebellar Diseases, Child, Child, Preschool, Female, GTPase-Activating Proteins, HeLa Cells, Homozygote, Humans, Male, Microcephaly, Mutation, Pedigree, Phenotype, Zebrafish}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.07.015}, author = {Marin-Valencia, Isaac and Gerondopoulos, Andreas and Zaki, Maha S and Ben-Omran, Tawfeg and Almureikhi, Mariam and Demir, Ercan and Guemez-Gamboa, Alicia and Gregor, Anne and Issa, Mahmoud Y and Appelhof, Bart and Roosing, Susanne and Musaev, Damir and Rosti, Basak and Wirth, Sara and Stanley, Valentina and Baas, Frank and Barr, Francis A and Gleeson, Joseph G} } @article {55, title = {Mutations in CEP120 cause Joubert syndrome as well as complex ciliopathy phenotypes.}, journal = {J Med Genet}, volume = {53}, year = {2016}, month = {2016 09}, pages = {608-15}, abstract = {

BACKGROUND: Ciliopathies are an extensive group of autosomal recessive or X-linked disorders with considerable genetic and clinical overlap, which collectively share multiple organ involvement and may result in lethal or viable phenotypes. In large numbers of cases the genetic defect remains yet to be determined. The aim of this study is to describe the mutational frequency and phenotypic spectrum of the CEP120 gene.

METHODS: Exome sequencing was performed in 145 patients with Joubert syndrome (JS), including 15 children with oral-facial-digital syndrome type VI (OFDVI) and 21 Meckel syndrome (MKS) fetuses. Moreover, exome sequencing was performed in one fetus with tectocerebellar dysraphia with occipital encephalocele (TCDOE), molar tooth sign and additional skeletal abnormalities. As a parallel study, 346 probands with a phenotype consistent with JS or related ciliopathies underwent next-generation sequencing-based targeted sequencing of 120 previously described and candidate ciliopathy genes.

RESULTS: We present six probands carrying nine distinct mutations (of which eight are novel) in the CEP120 gene, previously found mutated only in Jeune asphyxiating thoracic dystrophy (JATD). The CEP120-associated phenotype ranges from mild classical JS in four patients to more severe conditions in two fetuses, with overlapping features of distinct ciliopathies that include TCDOE, MKS, JATD and OFD syndromes. No obvious correlation is evident between the type or location of identified mutations and the ciliopathy phenotype.

CONCLUSION: Our findings broaden the spectrum of phenotypes caused by CEP120 mutations that account for nearly 1\% of patients with JS as well as for more complex ciliopathy phenotypes. The lack of clear genotype-phenotype correlation highlights the relevance of comprehensive genetic analyses in the diagnostics of ciliopathies.

}, keywords = {Abnormalities, Multiple, Amino Acid Sequence, Cell Cycle Proteins, Cerebellar Diseases, Cerebellum, Child, Ciliopathies, Encephalocele, Eye Abnormalities, Female, Genetic Association Studies, Genetic Predisposition to Disease, Genetic Testing, Humans, Kidney Diseases, Cystic, Male, Mutation, Mutation Rate, Orofaciodigital Syndromes, Pedigree, Phenotype, Retina, Sequence Alignment}, issn = {1468-6244}, doi = {10.1136/jmedgenet-2016-103832}, author = {Roosing, Susanne and Romani, Marta and Isrie, Mala and Rosti, Rasim Ozgur and Micalizzi, Alessia and Musaev, Damir and Mazza, Tommaso and Al-Gazali, Lihadh and Altunoglu, Umut and Boltshauser, Eugen and D{\textquoteright}Arrigo, Stefano and De Keersmaecker, Bart and Kayserili, H{\"u}lya and Brandenberger, Sarah and Kraoua, Ichraf and Mark, Paul R and McKanna, Trudy and Van Keirsbilck, Joachim and Moerman, Philippe and Poretti, Andrea and Puri, Ratna and Van Esch, Hilde and Gleeson, Joseph G and Valente, Enza Maria} } @article {148, title = {An siRNA-based functional genomics screen for the~identification of regulators of ciliogenesis and ciliopathy~genes.}, journal = {Nat Cell Biol}, volume = {17}, year = {2015}, month = {2015 Aug}, pages = {1074-1087}, abstract = {

Defects in primary cilium biogenesis underlie the ciliopathies, a growing group of genetic disorders. We describe a whole-genome siRNA-based reverse genetics screen for defects in biogenesis and/or maintenance of the primary cilium, obtaining a global resource. We identify 112 candidate ciliogenesis and ciliopathy genes, including 44 components of the ubiquitin-proteasome system, 12 G-protein-coupled receptors, and 3 pre-mRNA processing factors (PRPF6, PRPF8 and PRPF31) mutated in autosomal dominant retinitis pigmentosa. The PRPFs localize to the connecting cilium, and PRPF8- and PRPF31-mutated cells have ciliary defects. Combining the screen with exome sequencing data identified recessive mutations in PIBF1, also known as CEP90, and C21orf2, also known as LRRC76, as causes of the ciliopathies Joubert and Jeune syndromes. Biochemical approaches place C21orf2 within key ciliopathy-associated protein modules, offering an explanation for the skeletal and retinal involvement observed in individuals with C21orf2 variants. Our global, unbiased approaches provide insights into ciliogenesis complexity and identify roles for unanticipated pathways in human genetic disease.

}, keywords = {Abnormalities, Multiple, Animals, Caenorhabditis elegans, Cerebellar Diseases, Cerebellum, Cilia, Ciliary Motility Disorders, Databases, Genetic, Ellis-Van Creveld Syndrome, Eye Abnormalities, Genetic Markers, Genetic Predisposition to Disease, Genetic Testing, Genome-Wide Association Study, Genomics, HEK293 Cells, High-Throughput Nucleotide Sequencing, Humans, Kidney Diseases, Cystic, Membrane Proteins, Mice, Inbred C57BL, Mice, Knockout, Mutation, Phenotype, Photoreceptor Cells, Pregnancy Proteins, Proteins, Reproducibility of Results, Retina, RNA Interference, Suppressor Factors, Immunologic, Transfection, Zebrafish}, issn = {1476-4679}, doi = {10.1038/ncb3201}, author = {Wheway, Gabrielle and Schmidts, Miriam and Mans, Dorus A and Szymanska, Katarzyna and Nguyen, Thanh-Minh T and Racher, Hilary and Phelps, Ian G and Toedt, Grischa and Kennedy, Julie and Wunderlich, Kirsten A and Sorusch, Nasrin and Abdelhamed, Zakia A and Natarajan, Subaashini and Herridge, Warren and van Reeuwijk, Jeroen and Horn, Nicola and Boldt, Karsten and Parry, David A and Letteboer, Stef J F and Roosing, Susanne and Adams, Matthew and Bell, Sandra M and Bond, Jacquelyn and Higgins, Julie and Morrison, Ewan E and Tomlinson, Darren C and Slaats, Gisela G and van Dam, Teunis J P and Huang, Lijia and Kessler, Kristin and Giessl, Andreas and Logan, Clare V and Boyle, Evan A and Shendure, Jay and Anazi, Shamsa and Aldahmesh, Mohammed and Al Hazzaa, Selwa and Hegele, Robert A and Ober, Carole and Frosk, Patrick and Mhanni, Aizeddin A and Chodirker, Bernard N and Chudley, Albert E and Lamont, Ryan and Bernier, Francois P and Beaulieu, Chandree L and Gordon, Paul and Pon, Richard T and Donahue, Clem and Barkovich, A James and Wolf, Louis and Toomes, Carmel and Thiel, Christian T and Boycott, Kym M and McKibbin, Martin and Inglehearn, Chris F and Stewart, Fiona and Omran, Heymut and Huynen, Martijn A and Sergouniotis, Panagiotis I and Alkuraya, Fowzan S and Parboosingh, Jillian S and Innes, A Micheil and Willoughby, Colin E and Giles, Rachel H and Webster, Andrew R and Ueffing, Marius and Blacque, Oliver and Gleeson, Joseph G and Wolfrum, Uwe and Beales, Philip L and Gibson, Toby and Doherty, Dan and Mitchison, Hannah M and Roepman, Ronald and Johnson, Colin A} }