@article {857, title = {Heterozygous Gene Deficiency and Risk of Coronary Artery Disease.}, journal = {Circ Genom Precis Med}, volume = {13}, year = {2020}, month = {2020 10}, pages = {417-423}, abstract = {

BACKGROUND: Familial sitosterolemia is a rare Mendelian disorder characterized by hyperabsorption and decreased biliary excretion of dietary sterols. Affected individuals typically have complete genetic deficiency-homozygous loss-of-function (LoF) variants-in the or genes and have substantially elevated plasma sitosterol and LDL (low-density lipoprotein) cholesterol (LDL-C) levels. The impact of partial genetic deficiency of or -as occurs in heterozygous carriers of LoF variants-on LDL-C and risk of coronary artery disease (CAD) has remained uncertain.

METHODS: We first recruited 9 sitosterolemia families, identified causative LoF variants in or , and evaluated the associations of these or LoF variants with plasma phytosterols and lipid levels. We next assessed for LoF variants in or in CAD cases (n=29 321) versus controls (n=357 326). We tested the association of rare LoF variants in or with blood lipids and risk for CAD. Rare LoF variants were defined as protein-truncating variants with minor allele frequency <0.1\% in or .

RESULTS: In sitosterolemia families, 7 pedigrees harbored causative LoF variants in and 2 pedigrees in . Homozygous LoF variants in either or led to marked elevations in sitosterol and LDL-C. Of those sitosterolemia families, heterozygous carriers of LoF variants exhibited increased sitosterol and LDL-C levels compared with noncarriers. Within large-scale CAD case-control cohorts, prevalence of rare LoF variants in and in was ≈0.1\% each. heterozygous LoF variant carriers had significantly elevated LDL-C levels (25 mg/dL [95\% CI, 14-35]; =1.1{\texttimes}10) and were at 2-fold increased risk of CAD (odds ratio, 2.06 [95\% CI, 1.27-3.35]; =0.004). By contrast, heterozygous LoF carrier status was not associated with increased LDL-C or risk of CAD.

CONCLUSIONS: Although familial sitosterolemia is traditionally considered as a recessive disorder, we observed that heterozygous carriers of an LoF variant in had significantly increased sitosterol and LDL-C levels and a 2-fold increase in risk of CAD.

}, issn = {2574-8300}, doi = {10.1161/CIRCGEN.119.002871}, author = {Nomura, Akihiro and Emdin, Connor A and Won, Hong Hee and Peloso, Gina M and Natarajan, Pradeep and Ardissino, Diego and Danesh, John and Schunkert, Heribert and Correa, Adolfo and Bown, Matthew J and Samani, Nilesh J and Erdmann, Jeanette and McPherson, Ruth and Watkins, Hugh and Saleheen, Danish and Elosua, Roberto and Kawashiri, Masa-Aki and Tada, Hayato and Gupta, Namrata and Shah, Svati H and Rader, Daniel J and Gabriel, Stacey and Khera, Amit V and Kathiresan, Sekar} } @article {859, title = {A missense variant in Mitochondrial Amidoxime Reducing Component 1 gene and protection against liver disease.}, journal = {PLoS Genet}, volume = {16}, year = {2020}, month = {2020 04}, pages = {e1008629}, abstract = {

Analyzing 12,361 all-cause cirrhosis cases and 790,095 controls from eight cohorts, we identify a common missense variant in the Mitochondrial Amidoxime Reducing Component 1 gene (MARC1 p.A165T) that associates with protection from all-cause cirrhosis (OR 0.91, p = 2.3*10-11). This same variant also associates with lower levels of hepatic fat on computed tomographic imaging and lower odds of physician-diagnosed fatty liver as well as lower blood levels of alanine transaminase (-0.025 SD, 3.7*10-43), alkaline phosphatase (-0.025 SD, 1.2*10-37), total cholesterol (-0.030 SD, p = 1.9*10-36) and LDL cholesterol (-0.027 SD, p = 5.1*10-30) levels. We identified a series of additional MARC1 alleles (low-frequency missense p.M187K and rare protein-truncating p.R200Ter) that also associated with lower cholesterol levels, liver enzyme levels and reduced risk of cirrhosis (0 cirrhosis cases for 238 R200Ter carriers versus 17,046 cases of cirrhosis among 759,027 non-carriers, p = 0.04) suggesting that deficiency of the MARC1 enzyme may lower blood cholesterol levels and protect against cirrhosis.

}, keywords = {Alleles, Cholesterol, LDL, Coronary Artery Disease, Datasets as Topic, Fatty Liver, Female, Genetic Predisposition to Disease, Homozygote, Humans, Liver, Liver Cirrhosis, Liver Cirrhosis, Alcoholic, Loss of Function Mutation, Male, Middle Aged, Mitochondrial Proteins, Mutation, Missense, Oxidoreductases}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1008629}, author = {Emdin, Connor A and Haas, Mary E and Khera, Amit V and Aragam, Krishna and Chaffin, Mark and Klarin, Derek and Hindy, George and Jiang, Lan and Wei, Wei-Qi and Feng, Qiping and Karjalainen, Juha and Havulinna, Aki and Kiiskinen, Tuomo and Bick, Alexander and Ardissino, Diego and Wilson, James G and Schunkert, Heribert and McPherson, Ruth and Watkins, Hugh and Elosua, Roberto and Bown, Matthew J and Samani, Nilesh J and Baber, Usman and Erdmann, Jeanette and Gupta, Namrata and Danesh, John and Saleheen, Danish and Chang, Kyong-Mi and Vujkovic, Marijana and Voight, Ben and Damrauer, Scott and Lynch, Julie and Kaplan, David and Serper, Marina and Tsao, Philip and Mercader, Josep and Hanis, Craig and Daly, Mark and Denny, Joshua and Gabriel, Stacey and Kathiresan, Sekar} } @article {784, title = {The mutational constraint spectrum quantified from variation in 141,456 humans.}, journal = {Nature}, volume = {581}, year = {2020}, month = {2020 05}, pages = {434-443}, abstract = {

Genetic variants that inactivate protein-coding genes are a powerful source of information about the phenotypic consequences of gene disruption: genes that are crucial for the function of an organism will be depleted of such variants in natural populations, whereas non-essential genes will tolerate their accumulation. However, predicted loss-of-function variants are enriched for annotation errors, and tend to be found at extremely low frequencies, so their analysis requires careful variant annotation and very large sample sizes. Here we describe the aggregation of 125,748 exomes and 15,708 genomes from human sequencing studies into the Genome Aggregation Database (gnomAD). We identify 443,769 high-confidence predicted loss-of-function variants in this cohort after filtering for artefacts caused by sequencing and annotation errors. Using an improved model of human mutation rates, we classify human protein-coding genes along a spectrum that represents tolerance to inactivation, validate this classification using data from model organisms and engineered human cells, and show that it can be used to improve the power of gene discovery for both common and rare diseases.

}, keywords = {Adult, Brain, Cardiovascular Diseases, Cohort Studies, Databases, Genetic, Exome, Female, Genes, Essential, Genetic Predisposition to Disease, Genetic Variation, Genome, Human, Genome-Wide Association Study, Humans, Loss of Function Mutation, Male, Mutation Rate, Proprotein Convertase 9, Reproducibility of Results, RNA, Messenger, Whole Exome Sequencing, Whole Genome Sequencing}, issn = {1476-4687}, doi = {10.1038/s41586-020-2308-7}, author = {Karczewski, Konrad J and Francioli, Laurent C and Tiao, Grace and Cummings, Beryl B and Alf{\"o}ldi, Jessica and Wang, Qingbo and Collins, Ryan L and Laricchia, Kristen M and Ganna, Andrea and Birnbaum, Daniel P and Gauthier, Laura D and Brand, Harrison and Solomonson, Matthew and Watts, Nicholas A and Rhodes, Daniel and Singer-Berk, Moriel and England, Eleina M and Seaby, Eleanor G and Kosmicki, Jack A and Walters, Raymond K and Tashman, Katherine and Farjoun, Yossi and Banks, Eric and Poterba, Timothy and Wang, Arcturus and Seed, Cotton and Whiffin, Nicola and Chong, Jessica X and Samocha, Kaitlin E and Pierce-Hoffman, Emma and Zappala, Zachary and O{\textquoteright}Donnell-Luria, Anne H and Minikel, Eric Vallabh and Weisburd, Ben and Lek, Monkol and Ware, James S and Vittal, Christopher and Armean, Irina M and Bergelson, Louis and Cibulskis, Kristian and Connolly, Kristen M and Covarrubias, Miguel and Donnelly, Stacey and Ferriera, Steven and Gabriel, Stacey and Gentry, Jeff and Gupta, Namrata and Jeandet, Thibault and Kaplan, Diane and Llanwarne, Christopher and Munshi, Ruchi and Novod, Sam and Petrillo, Nikelle and Roazen, David and Ruano-Rubio, Valentin and Saltzman, Andrea and Schleicher, Molly and Soto, Jose and Tibbetts, Kathleen and Tolonen, Charlotte and Wade, Gordon and Talkowski, Michael E and Neale, Benjamin M and Daly, Mark J and MacArthur, Daniel G} } @article {836, title = {A structural variation reference for medical and population genetics.}, journal = {Nature}, volume = {581}, year = {2020}, month = {2020 05}, pages = {444-451}, abstract = {

Structural variants (SVs) rearrange large segments of DNA and can have profound consequences in evolution and human disease. As national biobanks, disease-association studies, and clinical genetic testing have grown increasingly reliant on genome sequencing, population references such as the Genome Aggregation Database (gnomAD) have become integral in the interpretation of single-nucleotide variants (SNVs). However, there are no reference maps of SVs from high-coverage genome sequencing comparable to those for SNVs. Here we present a reference of sequence-resolved SVs constructed from 14,891 genomes across diverse global populations (54\% non-European) in gnomAD. We discovered a rich and complex landscape of 433,371 SVs, from which we estimate that SVs are responsible for 25-29\% of all rare protein-truncating events per genome. We found strong correlations between natural selection against damaging SNVs and rare SVs that disrupt or duplicate protein-coding sequence, which suggests that genes that are highly intolerant to loss-of-function are also sensitive to increased dosage. We also uncovered modest selection against noncoding SVs in cis-regulatory elements, although selection against protein-truncating SVs was stronger than all noncoding effects. Finally, we identified very large (over one megabase), rare SVs in 3.9\% of samples, and estimate that 0.13\% of individuals may carry an SV that meets the existing criteria for clinically important incidental findings. This SV resource is freely distributed via the gnomAD browser and will have broad utility in population genetics, disease-association studies, and diagnostic screening.

}, keywords = {Continental Population Groups, Disease, Female, Genetic Testing, Genetic Variation, Genetics, Medical, Genetics, Population, Genome, Human, Genotyping Techniques, Humans, Male, Middle Aged, Mutation, Polymorphism, Single Nucleotide, Reference Standards, Selection, Genetic, Whole Genome Sequencing}, issn = {1476-4687}, doi = {10.1038/s41586-020-2287-8}, author = {Collins, Ryan L and Brand, Harrison and Karczewski, Konrad J and Zhao, Xuefang and Alf{\"o}ldi, Jessica and Francioli, Laurent C and Khera, Amit V and Lowther, Chelsea and Gauthier, Laura D and Wang, Harold and Watts, Nicholas A and Solomonson, Matthew and O{\textquoteright}Donnell-Luria, Anne and Baumann, Alexander and Munshi, Ruchi and Walker, Mark and Whelan, Christopher W and Huang, Yongqing and Brookings, Ted and Sharpe, Ted and Stone, Matthew R and Valkanas, Elise and Fu, Jack and Tiao, Grace and Laricchia, Kristen M and Ruano-Rubio, Valentin and Stevens, Christine and Gupta, Namrata and Cusick, Caroline and Margolin, Lauren and Taylor, Kent D and Lin, Henry J and Rich, Stephen S and Post, Wendy S and Chen, Yii-Der Ida and Rotter, Jerome I and Nusbaum, Chad and Philippakis, Anthony and Lander, Eric and Gabriel, Stacey and Neale, Benjamin M and Kathiresan, Sekar and Daly, Mark J and Banks, Eric and MacArthur, Daniel G and Talkowski, Michael E} } @article {514, title = {Loss of Protocadherin-12 Leads to Diencephalic-Mesencephalic Junction Dysplasia Syndrome.}, journal = {Ann Neurol}, volume = {84}, year = {2018}, month = {2018 Nov}, pages = {638-647}, abstract = {

OBJECTIVE: To identify causes of the autosomal-recessive malformation, diencephalic-mesencephalic junction dysplasia (DMJD) syndrome.

METHODS: Eight families with DMJD were studied by whole-exome or targeted sequencing, with detailed clinical and radiological characterization. Patient-derived induced pluripotent stem cells were derived into neural precursor and endothelial cells to study gene expression.

RESULTS: All patients showed biallelic mutations in the nonclustered protocadherin-12 (PCDH12) gene. The characteristic clinical presentation included progressive microcephaly, craniofacial dysmorphism, psychomotor disability, epilepsy, and axial hypotonia with variable appendicular spasticity. Brain imaging showed brainstem malformations and with frequent thinned corpus callosum with punctate brain calcifications, reflecting expression of PCDH12 in neural and endothelial cells. These cells showed lack of PCDH12 expression and impaired neurite outgrowth.

INTERPRETATION: DMJD patients have biallelic mutations in PCDH12 and lack of protein expression. These patients present with characteristic microcephaly and abnormalities of white matter tracts. Such pathogenic variants predict a poor outcome as a result of brainstem malformation and evidence of white matter tract defects, and should be added to the phenotypic spectrum associated with PCDH12-related conditions. Ann Neurol 2018;84:646-655.

}, issn = {1531-8249}, doi = {10.1002/ana.25327}, author = {Guemez-Gamboa, Alicia and {\c C}a{\u g}layan, Ahmet Okay and Stanley, Valentina and Gregor, Anne and Zaki, Maha S and Saleem, Sahar N and Musaev, Damir and McEvoy-Venneri, Jennifer and Belandres, Denice and Akizu, Naiara and Silhavy, Jennifer L and Schroth, Jana and Rosti, Rasim Ozgur and Copeland, Brett and Lewis, Steven M and Fang, Rebecca and Issa, Mahmoud Y and Per, H{\"u}seyin and G{\"u}m{\"u}{\c s}, Hakan and Bayram, Ayse Kacar and Kumanda{\c s}, Sefer and Akg{\"u}m{\"u}{\c s}, G{\"o}zde Tu{\u g}ce and Erson-Omay, Emine Z and Yasuno, Katsuhito and Bilguvar, Kaya and Heimer, Gali and Pillar, Nir and Shomron, Noam and Weissglas-Volkov, Daphna and Porat, Yuval and Einhorn, Yaron and Gabriel, Stacey and Ben-Zeev, Bruria and G{\"u}nel, Murat and Gleeson, Joseph G} } @article {37, title = {Biallelic Mutations in Citron Kinase Link Mitotic Cytokinesis to Human Primary Microcephaly.}, journal = {Am J Hum Genet}, volume = {99}, year = {2016}, month = {2016 Aug 04}, pages = {501-10}, abstract = {

Cell division terminates with cytokinesis and cellular separation. Autosomal-recessive primary microcephaly (MCPH) is a neurodevelopmental disorder characterized by a reduction in brain and head size at birth in addition to non-progressive intellectual disability. MCPH is genetically heterogeneous, and 16 loci are known to be associated with loss-of-function mutations predominantly affecting centrosomal-associated proteins, but the multiple roles of centrosomes in cellular function has left questions about etiology. Here, we identified three families affected by homozygous missense mutations in CIT, encoding citron rho-interacting kinase (CIT), which has established roles in cytokinesis. All mutations caused substitution of conserved amino acid residues in the kinase domain and impaired kinase activity. Neural progenitors that were differentiated from induced pluripotent stem cells (iPSCs) derived from individuals with these mutations exhibited abnormal cytokinesis with delayed mitosis, multipolar spindles, and increased apoptosis, rescued by CRISPR/Cas9 genome editing. Our results highlight the importance of cytokinesis in the pathology of primary microcephaly.

}, keywords = {Alleles, Apoptosis, Centrosome, Child, Child, Preschool, Cytokinesis, Female, Genes, Recessive, Humans, Infant, Newborn, Intracellular Signaling Peptides and Proteins, Male, Microcephaly, Mitosis, Mutation, Missense, Pedigree, Protein Serine-Threonine Kinases}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.07.004}, author = {Li, Hongda and Bielas, Stephanie L and Zaki, Maha S and Ismail, Samira and Farfara, Dorit and Um, Kyongmi and Rosti, Rasim O and Scott, Eric C and Tu, Shu and Chi, Neil C and Gabriel, Stacey and Erson-Omay, Emine Z and Ercan-Sencicek, A Gulhan and Yasuno, Katsuhito and {\c C}a{\u g}layan, Ahmet Okay and Kaymak{\c c}alan, Hande and Ekici, Bar{\i}{\c s} and Bilguvar, Kaya and G{\"u}nel, Murat 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 {252, title = {CLP1 founder mutation links tRNA splicing and maturation to cerebellar development and neurodegeneration.}, journal = {Cell}, volume = {157}, year = {2014}, month = {2014 Apr 24}, pages = {651-63}, abstract = {

Neurodegenerative diseases can occur so early as to affect neurodevelopment. From a cohort of more than 2,000 consanguineous families with childhood neurological disease, we identified a founder mutation in four independent pedigrees in cleavage and polyadenylation factor I subunit 1 (CLP1). CLP1 is a multifunctional kinase implicated in tRNA, mRNA, and siRNA maturation. Kinase activity of the CLP1 mutant protein was defective, and the tRNA endonuclease complex (TSEN) was destabilized, resulting in impaired pre-tRNA cleavage. Germline clp1 null zebrafish showed cerebellar neurodegeneration that was rescued by wild-type, but not mutant, human CLP1 expression. Patient-derived induced neurons displayed both depletion of mature tRNAs and accumulation of unspliced pre-tRNAs. Transfection of partially processed tRNA fragments into patient cells exacerbated an oxidative stress-induced reduction in cell survival. Our data link tRNA maturation to neuronal development and neurodegeneration through defective CLP1 function in humans.

}, keywords = {Animals, Brain, Cerebellum, Cleavage And Polyadenylation Specificity Factor, Female, Humans, Male, Mice, Models, Molecular, Neurodegenerative Diseases, Nuclear Proteins, Pedigree, Phosphotransferases, RNA Splicing, RNA, Transfer, Saccharomyces cerevisiae, Transcription Factors, Zebrafish, Zebrafish Proteins}, issn = {1097-4172}, doi = {10.1016/j.cell.2014.03.049}, author = {Schaffer, Ashleigh E and Eggens, Veerle R C and {\c C}a{\u g}layan, Ahmet Okay and Reuter, Miriam S and Scott, Eric and Coufal, Nicole G and Silhavy, Jennifer L and Xue, Yuanchao and Kayserili, H{\"u}lya and Yasuno, Katsuhito and Rosti, Rasim Ozgur and Abdellateef, Mostafa and Caglar, Caner and Kasher, Paul R and Cazemier, J Leonie and Weterman, Marian A and Cantagrel, Vincent and Cai, Na and Zweier, Christiane and Altunoglu, Umut and Satkin, N Bilge and Aktar, Fesih and Tuysuz, Beyhan and Yalcinkaya, Cengiz and Caksen, Huseyin and Bilguvar, Kaya and Fu, Xiang-Dong and Trotta, Christopher R and Gabriel, Stacey and Reis, Andr{\'e} and G{\"u}nel, Murat and Baas, Frank 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} }