@article {494, title = {A homozygous founder mutation in associates with a neurodevelopmental disorder characterised by microcephaly, epilepsy and autistic features.}, journal = {J Med Genet}, volume = {55}, year = {2018}, month = {2018 01}, pages = {48-54}, abstract = {

BACKGROUND: Transport protein particle (TRAPP) is a multisubunit complex that regulates membrane trafficking through the Golgi apparatus. The clinical phenotype associated with mutations in various TRAPP subunits has allowed elucidation of their functions in specific tissues. The role of some subunits in human disease, however, has not been fully established, and their functions remain uncertain.

OBJECTIVE: We aimed to expand the range of neurodevelopmental disorders associated with mutations in TRAPP subunits by exome sequencing of consanguineous families.

METHODS: Linkage and homozygosity mapping and candidate gene analysis were used to identify homozygous mutations in families. Patient fibroblasts were used to study splicing defect and zebrafish to model the disease.

RESULTS: We identified six individuals from three unrelated families with a founder homozygous splice mutation in , encoding a core subunit of the complex TRAPP I. Patients manifested a neurodevelopmental disorder characterised by microcephaly, epilepsy and autistic features, and showed splicing defect. Zebrafish morphants replicated the human phenotype, displaying decreased head size and neuronal hyperexcitability, leading to a lower seizure threshold.

CONCLUSION: This study provides clinical and functional evidence of the role of in brain development and function.

}, keywords = {Animals, Autistic Disorder, Epilepsy, Founder Effect, Genetic Association Studies, Homozygote, Humans, Microcephaly, Mutation, Neurodevelopmental Disorders, Phenotype, Vesicular Transport Proteins, Zebrafish}, issn = {1468-6244}, doi = {10.1136/jmedgenet-2017-104627}, author = {Marin-Valencia, Isaac and Novarino, Gaia and Johansen, Anide and Rosti, Basak and Issa, Mahmoud Y and Musaev, Damir and Bhat, Gifty and Scott, Eric and Silhavy, Jennifer L and Stanley, Valentina and Rosti, Rasim O and Gleeson, Jeremy W and Imam, Farhad B and Zaki, Maha S and Gleeson, Joseph G} } @article {351, title = {Biallelic mutations in the 3{\textquoteright} exonuclease TOE1 cause pontocerebellar hypoplasia and uncover a role in snRNA processing.}, journal = {Nat Genet}, volume = {49}, year = {2017}, month = {2017 Mar}, pages = {457-464}, abstract = {

Deadenylases are best known for degrading the poly(A) tail during mRNA decay. The deadenylase family has expanded throughout evolution and, in mammals, consists of 12 Mg-dependent 3{\textquoteright}-end RNases with substrate specificity that is mostly unknown. Pontocerebellar hypoplasia type 7 (PCH7) is a unique recessive syndrome characterized by neurodegeneration and ambiguous genitalia. We studied 12 human families with PCH7, uncovering biallelic, loss-of-function mutations in TOE1, which encodes an unconventional deadenylase. toe1-morphant zebrafish displayed midbrain and hindbrain degeneration, modeling PCH-like structural defects in vivo. Surprisingly, we found that TOE1 associated with small nuclear RNAs (snRNAs) incompletely processed spliceosomal. These pre-snRNAs contained 3{\textquoteright} genome-encoded tails often followed by post-transcriptionally added adenosines. Human cells with reduced levels of TOE1 accumulated 3{\textquoteright}-end-extended pre-snRNAs, and the immunoisolated TOE1 complex was sufficient for 3{\textquoteright}-end maturation of snRNAs. Our findings identify the cause of a neurodegenerative syndrome linked to snRNA maturation and uncover a key factor involved in the processing of snRNA 3{\textquoteright} ends.

}, keywords = {Alleles, Animals, Cerebellar Diseases, Exonucleases, Female, Humans, Male, Mice, Mutation, Neurodegenerative Diseases, Nuclear Proteins, RNA, Messenger, RNA, Small Nuclear, Spliceosomes, Zebrafish}, issn = {1546-1718}, doi = {10.1038/ng.3762}, author = {Lardelli, Rea M and Schaffer, Ashleigh E and Eggens, Veerle R C and Zaki, Maha S and Grainger, Stephanie and Sathe, Shashank and Van Nostrand, Eric L and Schlachetzki, Zinayida and Rosti, Basak and Akizu, Naiara and Scott, Eric and Silhavy, Jennifer L and Heckman, Laura Dean and Rosti, Rasim Ozgur and Dikoglu, Esra and Gregor, Anne and Guemez-Gamboa, Alicia and Musaev, Damir and Mande, Rohit and Widjaja, Ari and Shaw, Tim L and Markmiller, Sebastian and Marin-Valencia, Isaac and Davies, Justin H and de Meirleir, Linda and Kayserili, H{\"u}lya and Altunoglu, Umut and Freckmann, Mary Louise and Warwick, Linda and Chitayat, David and Blaser, Susan and {\c C}a{\u g}layan, Ahmet Okay and Bilguvar, Kaya and Per, H{\"u}seyin and Fagerberg, Christina and Christesen, Henrik T and Kibaek, Maria and Aldinger, Kimberly A and Manchester, David and Matsumoto, Naomichi and Muramatsu, Kazuhiro and Saitsu, Hirotomo and Shiina, Masaaki and Ogata, Kazuhiro and Foulds, Nicola and Dobyns, William B and Chi, Neil C and Traver, David and Spaccini, Luigina and Bova, Stefania Maria and Gabriel, Stacey B and G{\"u}nel, Murat and Valente, Enza Maria and Nassogne, Marie-Cecile and Bennett, Eric J and Yeo, Gene W and Baas, Frank and Lykke-Andersen, Jens and Gleeson, Joseph G} } @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 {179, title = {Biallelic mutations in SNX14 cause a syndromic form of cerebellar atrophy and lysosome-autophagosome dysfunction.}, journal = {Nat Genet}, volume = {47}, year = {2015}, month = {2015 May}, pages = {528-34}, abstract = {

Pediatric-onset ataxias often present clinically as developmental delay and intellectual disability, with prominent cerebellar atrophy as a key neuroradiographic finding. Here we describe a new clinically distinguishable recessive syndrome in 12 families with cerebellar atrophy together with ataxia, coarsened facial features and intellectual disability, due to truncating mutations in the sorting nexin gene SNX14, encoding a ubiquitously expressed modular PX domain-containing sorting factor. We found SNX14 localized to lysosomes and associated with phosphatidylinositol (3,5)-bisphosphate, a key component of late endosomes/lysosomes. Patient-derived cells showed engorged lysosomes and a slower autophagosome clearance rate upon autophagy induction by starvation. Zebrafish morphants for snx14 showed dramatic loss of cerebellar parenchyma, accumulation of autophagosomes and activation of apoptosis. Our results characterize a unique ataxia syndrome due to biallelic SNX14 mutations leading to lysosome-autophagosome dysfunction.

}, keywords = {Animals, Atrophy, Autophagy, Cerebellar Diseases, Cerebellum, Child, Preschool, Female, Gene Frequency, Humans, Infant, Lod Score, Lysosomal Storage Diseases, Lysosomes, Male, Mutation, Phagosomes, Sorting Nexins, Spinocerebellar Ataxias, Syndrome, Zebrafish}, issn = {1546-1718}, doi = {10.1038/ng.3256}, author = {Akizu, Naiara and Cantagrel, Vincent and Zaki, Maha S and Al-Gazali, Lihadh and Wang, Xin and Rosti, Rasim Ozgur and Dikoglu, Esra and Gelot, Antoinette Bernabe and Rosti, Basak and Vaux, Keith K and Scott, Eric M and Silhavy, Jennifer L and Schroth, Jana and Copeland, Brett and Schaffer, Ashleigh E and Gordts, Philip L S M and Esko, Jeffrey D and Buschman, Matthew D and Field, Seth J and Napolitano, Gennaro and Abdel-Salam, Ghada M and Ozgul, R Koksal and Sag{\i}roglu, Mahmut Samil and Azam, Matloob and Ismail, Samira and Aglan, Mona and Selim, Laila and Mahmoud, Iman G and Abdel-Hadi, Sawsan and Badawy, Amera El and Sadek, Abdelrahim A and Mojahedi, Faezeh and Kayserili, H{\"u}lya and Masri, Amira and Bastaki, Laila and Temtamy, Samia and M{\"u}ller, Ulrich and Desguerre, Isabelle and Casanova, Jean-Laurent and Dursun, Ali and G{\"u}nel, Murat and Gabriel, Stacey B and de Lonlay, Pascale and Gleeson, Joseph G} } @article {161, title = {Inactivating mutations in MFSD2A, required for omega-3 fatty acid transport in brain, cause a lethal microcephaly syndrome.}, journal = {Nat Genet}, volume = {47}, year = {2015}, month = {2015 Jul}, pages = {809-13}, abstract = {

Docosahexanoic acid (DHA) is the most abundant omega-3 fatty acid in brain, and, although it is considered essential, deficiency has not been linked to disease. Despite the large mass of DHA in phospholipids, the brain does not synthesize it. DHA is imported across the blood-brain barrier (BBB) through the major facilitator superfamily domain-containing 2a (MFSD2A) protein. MFSD2A transports DHA as well as other fatty acids in the form of lysophosphatidylcholine (LPC). We identify two families displaying MFSD2A mutations in conserved residues. Affected individuals exhibited a lethal microcephaly syndrome linked to inadequate uptake of LPC lipids. The MFSD2A mutations impaired transport activity in a cell-based assay. Moreover, when expressed in mfsd2aa-morphant zebrafish, mutants failed to rescue microcephaly, BBB breakdown and lethality. Our results establish a link between transport of DHA and LPCs by MFSD2A and human brain growth and function, presenting the first evidence of monogenic disease related to transport of DHA in humans.

}, keywords = {Adolescent, Animals, Biological Transport, Blood-Brain Barrier, Brain, Case-Control Studies, Child, Child, Preschool, Consanguinity, Fatty Acids, Omega-3, Female, Genes, Lethal, Genetic Association Studies, HEK293 Cells, Humans, Infant, Male, Mice, Knockout, Microcephaly, Mutation, Missense, Syndrome, Tumor Suppressor Proteins, Zebrafish}, issn = {1546-1718}, doi = {10.1038/ng.3311}, author = {Guemez-Gamboa, Alicia and Nguyen, Long N and Yang, Hongbo and Zaki, Maha S and Kara, Majdi and Ben-Omran, Tawfeg and Akizu, Naiara and Rosti, Rasim Ozgur and Rosti, Basak and Scott, Eric and Schroth, Jana and Copeland, Brett and Vaux, Keith K and Cazenave-Gassiot, Amaury and Quek, Debra Q Y and Wong, Bernice H and Tan, Bryan C and Wenk, Markus R and G{\"u}nel, Murat and Gabriel, Stacey and Chi, Neil C and Silver, David L and Gleeson, Joseph G} } @article {268, title = {Exome sequencing links corticospinal motor neuron disease to common neurodegenerative disorders.}, journal = {Science}, volume = {343}, year = {2014}, month = {2014 Jan 31}, pages = {506-511}, abstract = {

Hereditary spastic paraplegias (HSPs) are neurodegenerative motor neuron diseases characterized by progressive age-dependent loss of corticospinal motor tract function. Although the genetic basis is partly understood, only a fraction of cases can receive a genetic diagnosis, and a global view of HSP is lacking. By using whole-exome sequencing in combination with network analysis, we identified 18 previously unknown putative HSP genes and validated nearly all of these genes functionally or genetically. The pathways highlighted by these mutations link HSP to cellular transport, nucleotide metabolism, and synapse and axon development. Network analysis revealed a host of further candidate genes, of which three were mutated in our cohort. Our analysis links HSP to other neurodegenerative disorders and can facilitate gene discovery and mechanistic understanding of disease.

}, keywords = {Animals, Axons, Biological Transport, Cohort Studies, Exome, Gene Regulatory Networks, Genetic Association Studies, Humans, Motor Neuron Disease, Mutation, Neurons, Nucleotides, Pyramidal Tracts, Sequence Analysis, DNA, Spastic Paraplegia, Hereditary, Synapses, Transcriptome, Zebrafish}, issn = {1095-9203}, doi = {10.1126/science.1247363}, author = {Novarino, Gaia and Fenstermaker, Ali G and Zaki, Maha S and Hofree, Matan and Silhavy, Jennifer L and Heiberg, Andrew D and Abdellateef, Mostafa and Rosti, Basak and Scott, Eric and Mansour, Lobna and Masri, Amira and Kayserili, H{\"u}lya and Al-Aama, Jumana Y and Abdel-Salam, Ghada M H and Karminejad, Ariana and Kara, Majdi and Kara, Bulent and Bozorgmehri, Bita and Ben-Omran, Tawfeg and Mojahedi, Faezeh and El Din Mahmoud, Iman Gamal and Bouslam, Naima and Bouhouche, Ahmed and Benomar, Ali and Hanein, Sylvain and Raymond, Laure and Forlani, Sylvie and Mascaro, Massimo and Selim, Laila and Shehata, Nabil and Al-Allawi, Nasir and Bindu, P S and Azam, Matloob and G{\"u}nel, Murat and Caglayan, Ahmet and Bilguvar, Kaya and Tolun, Aslihan and Issa, Mahmoud Y and Schroth, Jana and Spencer, Emily G and Rosti, Rasim O and Akizu, Naiara and Vaux, Keith K and Johansen, Anide and Koh, Alice A and Megahed, Hisham and Durr, Alexandra and Brice, Alexis and Stevanin, Giovanni and Gabriel, Stacy B and Ideker, Trey and Gleeson, Joseph G} } @article {278, title = {Mutations in CSPP1 lead to classical Joubert syndrome.}, journal = {Am J Hum Genet}, volume = {94}, year = {2014}, month = {2014 Jan 02}, pages = {80-6}, abstract = {

Joubert syndrome and related disorders (JSRDs) are genetically heterogeneous and characterized by a distinctive mid-hindbrain malformation. Causative mutations lead to primary cilia dysfunction, which often results in variable involvement of other organs such as the liver, retina, and kidney. We identified predicted null mutations in CSPP1 in six individuals affected by classical JSRDs. CSPP1 encodes a protein localized to centrosomes and spindle poles, as well as to the primary cilium. Despite the known interaction between CSPP1 and nephronophthisis-associated proteins, none of the affected individuals in our cohort presented with kidney disease, and further, screening of a large cohort of individuals with nephronophthisis demonstrated no mutations. CSPP1 is broadly expressed in neural tissue, and its encoded protein localizes to the primary cilium in an in~vitro model of human neurogenesis. Here, we show abrogated protein levels and ciliogenesis in affected fibroblasts. Our data thus suggest that CSPP1 is involved in neural-specific functions of primary cilia.

}, keywords = {Abnormalities, Multiple, Brain, Cell Cycle Proteins, Centrosome, Cerebellar Diseases, Cerebellum, Cilia, Cohort Studies, Eye Abnormalities, Fibroblasts, Gene Deletion, Humans, Image Processing, Computer-Assisted, Kidney Diseases, Cystic, Microtubule-Associated Proteins, Polymorphism, Single Nucleotide, Retina}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2013.11.015}, author = {Akizu, Naiara and Silhavy, Jennifer L and Rosti, Rasim Ozgur and Scott, Eric and Fenstermaker, Ali G and Schroth, Jana and Zaki, Maha S and Sanchez, Henry and Gupta, Neerja and Kabra, Madhulika and Kara, Majdi and Ben-Omran, Tawfeg and Rosti, Basak and Guemez-Gamboa, Alicia and Spencer, Emily and Pan, Roger and Cai, Na and Abdellateef, Mostafa and Gabriel, Stacey and Halbritter, Jan and Hildebrandt, Friedhelm and van Bokhoven, Hans and G{\"u}nel, Murat and Gleeson, Joseph G} } @article {309, title = {Mutations in LAMB1 cause cobblestone brain malformation without muscular or ocular abnormalities.}, journal = {Am J Hum Genet}, volume = {92}, year = {2013}, month = {2013 Mar 07}, pages = {468-74}, abstract = {

Cobblestone brain malformation (COB) is a neuronal migration disorder characterized by protrusions of neurons beyond the first cortical layer at the pial surface of the brain. It is usually seen in association with dystroglycanopathy types of congenital muscular dystrophies (CMDs) and ocular abnormalities termed muscle-eye-brain disease. Here we report homozygous deleterious mutations in LAMB1, encoding laminin subunit beta-1, in two families with autosomal-recessive COB. Affected individuals displayed a constellation of brain malformations including cortical gyral and white-matter signal abnormalities, severe cerebellar dysplasia, brainstem hypoplasia, and occipital encephalocele, but they had less apparent ocular or muscular abnormalities than are typically observed in COB. LAMB1 is localized to the pial basement membrane, suggesting that defective connection between radial glial cells and the pial surface mediated by LAMB1 leads to this malformation.

}, keywords = {Basement Membrane, Brain, Cerebellum, Cerebral Cortex, Encephalocele, Female, Genetic Predisposition to Disease, Homozygote, Humans, Laminin, Male, Muscular Dystrophies, Nervous System Malformations, Neuroglia, Neurons, Sequence Deletion, Walker-Warburg Syndrome}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2013.02.005}, author = {Radmanesh, Farid and {\c C}a{\u g}layan, Ahmet Okay and Silhavy, Jennifer L and Yilmaz, Cahide and Cantagrel, Vincent and Omar, Tarek and Rosti, Basak and Kaymak{\c c}alan, Hande and Gabriel, Stacey and Li, Mingfeng and {\v S}estan, Nenad and Bilguvar, Kaya and Dobyns, William B and Zaki, Maha S and G{\"u}nel, Murat and Gleeson, Joseph G} }