@article {910, title = {Pathogenic Variants in CEP85L Cause Sporadic and Familial Posterior Predominant Lissencephaly.}, journal = {Neuron}, volume = {106}, year = {2020}, month = {2020 04 22}, pages = {237-245.e8}, abstract = {

Lissencephaly (LIS), denoting a "smooth brain," is characterized by the absence of normal cerebral convolutions with abnormalities of cortical thickness. Pathogenic variants in over 20 genes are associated with LIS. The majority of posterior predominant LIS is caused by pathogenic variants in LIS1~(also known as PAFAH1B1), although a significant fraction remains without a known genetic etiology. We now implicate CEP85L as an important cause of~posterior predominant LIS, identifying 13 individuals with rare, heterozygous CEP85L variants, including 2 families with autosomal dominant inheritance. We show that CEP85L is a centrosome protein localizing to the pericentriolar material, and knockdown of Cep85l causes a neuronal migration defect in mice. LIS1 also localizes to the centrosome, suggesting that this organelle is key to the mechanism of posterior predominant LIS.

}, keywords = {Adolescent, Adult, Age of Onset, Animals, Centrosome, Child, Child, Preschool, Chromosome Aberrations, Classical Lissencephalies and Subcortical Band Heterotopias, Cytoskeletal Proteins, Female, Gene Knockdown Techniques, Genetic Variation, Heterozygote, Humans, Infant, Magnetic Resonance Imaging, Male, Mice, Mutation, Oncogene Proteins, Fusion, Pedigree, Seizures, Young Adult}, issn = {1097-4199}, doi = {10.1016/j.neuron.2020.01.027}, author = {Tsai, Meng-Han and Muir, Alison M and Wang, Won-Jing and Kang, Yi-Ning and Yang, Kun-Chuan and Chao, Nian-Hsin and Wu, Mei-Feng and Chang, Ying-Chao and Porter, Brenda E and Jansen, Laura A and Sebire, Guillaume and Deconinck, Nicolas and Fan, Wen-Lang and Su, Shih-Chi and Chung, Wen-Hung and Almanza Fuerte, Edith P and Mehaffey, Michele G and Ng, Ching-Ching and Chan, Chung-Kin and Lim, Kheng-Seang and Leventer, Richard J and Lockhart, Paul J and Riney, Kate and Damiano, John A and Hildebrand, Michael S and Mirzaa, Ghayda M and Dobyns, William B and Berkovic, Samuel F and Scheffer, Ingrid E and Tsai, Jin-Wu and Mefford, Heather C} } @article {489, title = {Insights into clonal haematopoiesis from 8,342 mosaic chromosomal alterations.}, journal = {Nature}, volume = {559}, year = {2018}, month = {2018 07}, pages = {350-355}, abstract = {

The selective pressures that shape clonal evolution in healthy individuals are largely unknown. Here we investigate 8,342 mosaic chromosomal alterations, from 50~kb to 249~Mb long, that we uncovered in blood-derived DNA from 151,202 UK Biobank participants using phase-based computational techniques (estimated false discovery rate, 6-9\%). We found six loci at which inherited variants associated strongly with the acquisition of deletions or loss of heterozygosity in cis. At three such loci (MPL, TM2D3-TARSL2, and FRA10B), we identified a likely causal variant that acted with high penetrance (5-50\%). Inherited alleles at one locus appeared to affect the probability of somatic mutation, and at three other loci to be objects of positive or negative clonal selection. Several specific mosaic chromosomal alterations were strongly associated with future haematological malignancies. Our results reveal a multitude of paths towards clonal expansions with a wide range of effects on human health.

}, keywords = {Adult, Aged, Alleles, Biological Specimen Banks, Chromosome Aberrations, Chromosome Breakage, Chromosome Fragile Sites, Chromosomes, Human, Pair 10, Clone Cells, Female, Health, Hematologic Neoplasms, Hematopoiesis, Humans, Male, Middle Aged, Mosaicism, Penetrance, United Kingdom}, issn = {1476-4687}, doi = {10.1038/s41586-018-0321-x}, author = {Loh, Po-Ru and Genovese, Giulio and Handsaker, Robert E and Finucane, Hilary K and Reshef, Yakir A and Palamara, Pier Francesco and Birmann, Brenda M and Talkowski, Michael E and Bakhoum, Samuel F and McCarroll, Steven A and Price, Alkes L} } @article {348, title = {An Organismal CNV Mutator Phenotype Restricted to Early Human Development.}, journal = {Cell}, volume = {168}, year = {2017}, month = {2017 02 23}, pages = {830-842.e7}, abstract = {

De novo copy number variants (dnCNVs) arising at~multiple loci in a personal genome have usually been considered to reflect cancer somatic genomic instabilities. We describe a multiple dnCNV (MdnCNV) phenomenon in which individuals with genomic disorders carry five to ten constitutional dnCNVs. These CNVs originate from independent formation incidences, are predominantly tandem duplications or complex gains, exhibit breakpoint junction features reminiscent of replicative repair, and show increased de novo point mutations flanking the rearrangement junctions. The active CNV mutation shower appears to be restricted to a transient perizygotic period. We~propose that a defect in the CNV formation process is responsible for the "CNV-mutator state," and this state is dampened after early embryogenesis. The constitutional MdnCNV phenomenon resembles chromosomal instability in various cancers. Investigations of this phenomenon may provide unique access to understanding genomic disorders, structural variant mutagenesis, human evolution, and cancer biology.

}, keywords = {Chromosome Aberrations, Chromosome Breakpoints, Chromosome Duplication, DNA Copy Number Variations, DNA Replication, Embryonic Development, Female, Gametogenesis, Genetic Diseases, Inborn, Genomic Instability, Humans, Male, Mutation}, issn = {1097-4172}, doi = {10.1016/j.cell.2017.01.037}, author = {Liu, Pengfei and Yuan, Bo and Carvalho, Claudia M B and Wuster, Arthur and Walter, Klaudia and Zhang, Ling and Gambin, Tomasz and Chong, Zechen and Campbell, Ian M and Coban Akdemir, Zeynep and Gelowani, Violet and Writzl, Karin and Bacino, Carlos A and Lindsay, Sarah J and Withers, Marjorie and Gonzaga-Jauregui, Claudia and Wiszniewska, Joanna and Scull, Jennifer and Stankiewicz, Pawe{\l} and Jhangiani, Shalini N and Muzny, Donna M and Zhang, Feng and Chen, Ken and Gibbs, Richard A and Rautenstrauss, Bernd and Cheung, Sau Wai and Smith, Janice and Breman, Amy and Shaw, Chad A and Patel, Ankita and Hurles, Matthew E and Lupski, James R} } @article {49, title = {Ataxia-Pancytopenia Syndrome Is Caused by Missense Mutations in SAMD9L.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 Jun 02}, pages = {1146-1158}, abstract = {

Ataxia-pancytopenia (AP) syndrome is characterized by cerebellar ataxia, variable hematologic cytopenias, and predisposition to marrow failure and myeloid leukemia, sometimes associated with monosomy 7. Here, in the four-generation family UW-AP, linkage analysis revealed four regions that provided the maximal LOD scores possible, one of which was in a commonly microdeleted chromosome 7q region. Exome sequencing identified a missense mutation (c.2640C>A, p.His880Gln) in the sterile alpha motif domain containing 9-like gene (SAMD9L) that completely cosegregated with disease. By targeted sequencing of SAMD9L, we subsequently identified a different missense mutation (c.3587G>C, p.Cys1196Ser) in affected members of the first described family with AP syndrome, Li-AP. Neither variant is reported in the public databases, both affect highly conserved amino acid residues, and both are predicted to be damaging. With time in culture, lymphoblastic cell lines (LCLs) from two affected individuals in family UW-AP exhibited copy-neutral loss of heterozygosity for large portions of the long arm of chromosome 7, resulting in retention of only the wild-type SAMD9L allele. Newly established LCLs from both individuals demonstrated the same phenomenon. In addition, targeted capture and sequencing of SAMD9L in uncultured blood DNA from both individuals showed bias toward the wild-type allele. These observations indicate in~vivo hematopoietic mosaicism. The hematopoietic cytopenias that characterize AP syndrome and the selective advantage for clones that have lost the mutant allele support the postulated role of SAMD9L in the regulation of cell proliferation. Furthermore, we show that AP syndrome is distinct from the dyskeratoses congenita telomeropathies, with which it shares some clinical characteristics.

}, keywords = {Adolescent, Adult, Cerebellar Ataxia, Child, Chromosome Aberrations, Chromosomes, Human, Pair 7, Exome, Female, Genetic Linkage, Genotype, High-Throughput Nucleotide Sequencing, Humans, Intracellular Signaling Peptides and Proteins, Loss of Heterozygosity, Male, Middle Aged, Mutation, Missense, Pancytopenia, Pedigree, Proteins, Tumor Suppressor Proteins, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.04.009}, author = {Chen, Dong-Hui and Below, Jennifer E and Shimamura, Akiko and Keel, Sioban B and Matsushita, Mark and Wolff, John and Sul, Youngmee and Bonkowski, Emily and Castella, Maria and Taniguchi, Toshiyasu and Nickerson, Deborah and Papayannopoulou, Thalia and Bird, Thomas D and Raskind, Wendy H} } @article {531, title = {Update on the Toriello-Carey syndrome.}, journal = {Am J Med Genet A}, volume = {170}, year = {2016}, month = {2016 10}, pages = {2551-8}, abstract = {

Toriello and Carey described a provisionally-unique syndrome comprised of agenesis of the corpus callosum, Pierre Robin anomaly, and a characteristic facial phenotype. Because the condition affected siblings, this entity was postulated to be an autosomal recessive multiple anomaly syndrome. Several patients were subsequently reported, and over time, it became apparent that the Toriello-Carey syndrome was etiologically heterogeneous. Based on previous reports, it is estimated that at least 20\% of patients with a clinical diagnosis of Toriello-Carey syndrome have a chromosomal anomaly as the basis of the phenotype. However, no basis for the non-chromosomal cases has been found. This review summarizes the literature to date and provides speculation regarding the possible explanations for failing to find the cause of Toriello-Carey syndrome. {\textcopyright} 2016 Wiley Periodicals, Inc.

}, keywords = {Agenesis of Corpus Callosum, Chromosome Aberrations, Craniofacial Abnormalities, Female, Genetic Association Studies, Heart Defects, Congenital, Humans, Limb Deformities, Congenital, Male, Phenotype, Pierre Robin Syndrome, Urogenital Abnormalities}, issn = {1552-4833}, doi = {10.1002/ajmg.a.37735}, author = {Toriello, Helga V and Colley, Chelsey and Bamshad, Michael} } @article {176, title = {PacBio-LITS: a large-insert targeted sequencing method for characterization of human disease-associated chromosomal structural variations.}, journal = {BMC Genomics}, volume = {16}, year = {2015}, month = {2015 Mar 19}, pages = {214}, abstract = {

BACKGROUND: Generation of long (>5 Kb) DNA sequencing reads provides an approach for interrogation of complex regions in the human genome. Currently, large-insert whole genome sequencing (WGS) technologies from Pacific Biosciences (PacBio) enable analysis of chromosomal structural variations (SVs), but the cost to achieve the required sequence coverage across the entire human genome is high.

RESULTS: We developed a method (termed PacBio-LITS) that combines oligonucleotide-based DNA target-capture enrichment technologies with PacBio large-insert library preparation to facilitate SV studies at specific chromosomal regions. PacBio-LITS provides deep sequence coverage at the specified sites at substantially reduced cost compared with PacBio WGS. The efficacy of PacBio-LITS is illustrated by delineating the breakpoint junctions of low copy repeat (LCR)-associated complex structural rearrangements on chr17p11.2 in patients diagnosed with Potocki-Lupski syndrome (PTLS; MIM$\#$610883). We successfully identified previously determined breakpoint junctions in three PTLS cases, and also were able to discover novel junctions in repetitive sequences, including LCR-mediated breakpoints. The new information has enabled us to propose mechanisms for formation of these structural variants.

CONCLUSIONS: The new method leverages the cost efficiency of targeted capture-sequencing as well as the mappability and scaffolding capabilities of long sequencing reads generated by the PacBio platform. It is therefore suitable for studying complex SVs, especially those involving LCRs, inversions, and the generation of chimeric Alu elements at the breakpoints. Other genomic research applications, such as haplotype phasing and small insertion and deletion validation could also benefit from this technology.

}, keywords = {Chromosome Aberrations, Gene Library, Gene Rearrangement, Genetic Association Studies, Genomics, High-Throughput Nucleotide Sequencing, Humans, Workflow}, issn = {1471-2164}, doi = {10.1186/s12864-015-1370-2}, author = {Wang, Min and Beck, Christine R and English, Adam C and Meng, Qingchang and Buhay, Christian and Han, Yi and Doddapaneni, Harsha V and Yu, Fuli and Boerwinkle, Eric and Lupski, James R and Muzny, Donna M and Gibbs, Richard A} } @article {222, title = {Parent of origin, mosaicism, and recurrence risk: probabilistic modeling explains the broken symmetry of transmission genetics.}, journal = {Am J Hum Genet}, volume = {95}, year = {2014}, month = {2014 Oct 02}, pages = {345-59}, abstract = {

Most new mutations are observed to arise in fathers, and increasing paternal age positively correlates with the risk of new variants. Interestingly, new mutations in X-linked recessive disease show elevated familial recurrence rates. In male offspring, these mutations must be inherited from mothers. We previously developed a simulation model to consider parental mosaicism as a source of transmitted mutations. In this paper, we extend and formalize the model to provide analytical results and flexible formulas. The results implicate parent of origin and parental mosaicism as central variables in recurrence risk. Consistent with empirical data, our model predicts that more transmitted mutations arise in fathers and that this tendency increases as fathers age. Notably, the lack of expansion later in the male germline determines relatively lower variance in the proportion of mutants, which decreases with paternal age. Subsequently, observation of a transmitted mutation has less impact on the expected risk for future offspring. Conversely, for the female germline, which arrests after clonal expansion in early development, variance in the mutant proportion is higher, and observation of a transmitted mutation dramatically increases the expected risk of recurrence in another pregnancy. Parental somatic mosaicism considerably elevates risk for both parents. These findings have important implications for genetic counseling and for understanding patterns of recurrence in transmission genetics. We provide a convenient online tool and source code implementing our analytical results. These tools permit varying the underlying parameters that influence recurrence risk and could be useful for analyzing risk in diverse family structures.

}, keywords = {Adult, Aged, Aged, 80 and over, Chromosome Aberrations, DNA Copy Number Variations, Fathers, Female, Gametogenesis, Genetic Diseases, Inborn, Genomics, Germ Cells, Germ-Line Mutation, Humans, Inheritance Patterns, Male, Middle Aged, Models, Theoretical, Mosaicism, Mothers, Pregnancy, Recurrence, Risk Factors, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.08.010}, author = {Campbell, Ian M and Stewart, Jonathan R and James, Regis A and Lupski, James R and Stankiewicz, Pawe{\l} and Olofsson, Peter and Shaw, Chad A} }