@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 {112, title = {Low-level APC mutational mosaicism is the underlying cause in a substantial fraction of unexplained colorectal adenomatous polyposis cases.}, journal = {J Med Genet}, volume = {53}, year = {2016}, month = {2016 Mar}, pages = {172-9}, abstract = {

BACKGROUND: In 30-50\% of patients with colorectal adenomatous polyposis, no germline mutation in the known genes APC, causing familial adenomatous polyposis, MUTYH, causing MUTYH-associated polyposis, or POLE or POLD1, causing polymerase-proofreading-associated polyposis can be identified, although a hereditary aetiology is likely. This study aimed to explore the impact of APC mutational mosaicism in unexplained polyposis.

METHODS: To comprehensively screen for somatic low-level APC mosaicism, high-coverage next-generation sequencing of the APC gene was performed using DNA from leucocytes and a total of 53 colorectal tumours from 20 unrelated patients with unexplained sporadic adenomatous polyposis. APC mosaicism was assumed if the same loss-of-function APC mutation was present in >= 2 anatomically separated colorectal adenomas/carcinomas per patient. All mutations were validated using diverse methods.

RESULTS: In 25\% (5/20) of patients, somatic mosaicism of a pathogenic APC mutation was identified as underlying cause of the disease. In 2/5 cases, the mosaic level in leucocyte DNA was slightly below the sensitivity threshold of Sanger sequencing; while in 3/5 cases, the allelic fraction was either very low (0.1-1\%) or no mutations were detectable. The majority of mosaic mutations were located outside the somatic mutation cluster region of the gene.

CONCLUSIONS: The present data indicate a high prevalence of pathogenic mosaic APC mutations below the detection thresholds of routine diagnostics in adenomatous polyposis, even if high-coverage sequencing of leucocyte DNA alone is taken into account. This has important implications for both routine work-up and strategies to identify new causative genes in this patient group.

}, keywords = {Adenomatous Polyposis Coli, Adolescent, Adult, Colorectal Neoplasms, Genes, APC, High-Throughput Nucleotide Sequencing, Humans, Middle Aged, Mutation, Mutation Rate}, issn = {1468-6244}, doi = {10.1136/jmedgenet-2015-103468}, author = {Spier, Isabel and Drichel, Dmitriy and Kerick, Martin and Kirfel, Jutta and Horpaopan, Sukanya and Laner, Andreas and Holzapfel, Stefanie and Peters, Sophia and Adam, Ronja and Zhao, Bixiao and Becker, Tim and Lifton, Richard P and Perner, Sven and Hoffmann, Per and Kristiansen, Glen and Timmermann, Bernd and N{\"o}then, Markus M and Holinski-Feder, Elke and Schweiger, Michal R and Aretz, Stefan} } @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} }