@article {617, title = {Predicting human genes susceptible to genomic instability associated with /-mediated rearrangements.}, journal = {Genome Res}, volume = {28}, year = {2018}, month = {2018 08}, pages = {1228-1242}, abstract = {

elements, the short interspersed element numbering more than 1 million copies per human genome, can mediate the formation of copy number variants (CNVs) between substrate pairs. These /-mediated rearrangements (AAMRs) can result in pathogenic variants that cause diseases. To investigate the impact of AAMR on gene variation and human health, we first characterized s that are involved in mediating CNVs (CNV-s) and observed that these s tend to be evolutionarily younger. We then computationally generated, with the assistance of a supercomputer, a test data set consisting of 78 million pairs and predicted \~{}18\% of them are potentially susceptible to AAMR. We further determined the relative risk of AAMR in 12,074 OMIM genes using the count of predicted CNV- pairs and experimentally validated the predictions with 89 samples selected by correlating predicted hotspots with a database of CNVs identified by clinical chromosomal microarrays (CMAs) on the genomes of approximately 54,000 subjects. We fine-mapped 47 duplications, 40 deletions, and two complex rearrangements and examined a total of 52 breakpoint junctions of simple CNVs. Overall, 94\% of the candidate breakpoints were at least partially mediated. We successfully predicted all (100\%) of pairs that mediated deletions ( = 21) and achieved an 87\% positive predictive value overall when including AAMR-generated deletions and duplications. We provided a tool, AluAluCNVpredictor, for assessing AAMR hotspots and their role in human disease. These results demonstrate the utility of our predictive model and provide insights into the genomic features and molecular mechanisms underlying AAMR.

}, keywords = {Alu Elements, DNA Copy Number Variations, Gene Duplication, Genome, Human, Genomic Instability, Humans, Sequence Deletion}, issn = {1549-5469}, doi = {10.1101/gr.229401.117}, author = {Song, Xiaofei and Beck, Christine R and Du, Renqian and Campbell, Ian M and Coban-Akdemir, Zeynep and Gu, Shen and Breman, Amy M and Stankiewicz, Pawel and Ira, Grzegorz and Shaw, Chad A and Lupski, James R} } @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 {170, title = {Alu-mediated diverse and complex pathogenic copy-number variants within human chromosome 17 at p13.3.}, journal = {Hum Mol Genet}, volume = {24}, year = {2015}, month = {2015 Jul 15}, pages = {4061-77}, abstract = {

Alu repetitive elements are known to be major contributors to genome instability by generating Alu-mediated copy-number variants (CNVs). Most of the reported Alu-mediated CNVs are simple deletions and duplications, and the mechanism underlying Alu-Alu-mediated rearrangement has been attributed to non-allelic homologous recombination (NAHR). Chromosome 17 at the p13.3 genomic region lacks extensive low-copy repeat architecture; however, it is highly enriched for Alu repetitive elements, with a fraction of 30\% of total sequence annotated in the human reference genome, compared with the 10\% genome-wide and 18\% on chromosome 17. We conducted mechanistic studies of the 17p13.3 CNVs by performing high-density oligonucleotide array comparative genomic hybridization, specifically interrogating the 17p13.3 region with \~{}150 bp per probe density; CNV breakpoint junctions were mapped to nucleotide resolution by polymerase chain reaction and Sanger sequencing. Studied rearrangements include 5 interstitial deletions, 14 tandem duplications, 7 terminal deletions and 13 complex genomic rearrangements (CGRs). Within the 17p13.3 region, Alu-Alu-mediated rearrangements were identified in 80\% of the interstitial deletions, 46\% of the tandem duplications and 50\% of the CGRs, indicating that this mechanism was a major contributor for formation of breakpoint junctions. Our studies suggest that Alu repetitive elements facilitate formation of non-recurrent CNVs, CGRs and other structural aberrations of chromosome 17 at p13.3. The common observation of Alu-mediated rearrangement in CGRs and breakpoint junction sequences analysis further demonstrates that this type of mechanism is unlikely attributed to NAHR, but rather may be due to a recombination-coupled DNA replicative repair process.

}, keywords = {Alleles, Alu Elements, Base Sequence, Chromosomes, Human, Pair 17, Comparative Genomic Hybridization, DNA Copy Number Variations, Female, Gene Duplication, Gene Rearrangement, Genome, Human, Genomic Instability, Genomics, Homologous Recombination, Humans, Male, Molecular Sequence Data, Segmental Duplications, Genomic, Sequence Deletion}, issn = {1460-2083}, doi = {10.1093/hmg/ddv146}, author = {Gu, Shen and Yuan, Bo and Campbell, Ian M and Beck, Christine R and Carvalho, Claudia M B and Nagamani, Sandesh C S and Erez, Ayelet and Patel, Ankita and Bacino, Carlos A and Shaw, Chad A and Stankiewicz, Pawe{\l} and Cheung, Sau Wai and Bi, Weimin and Lupski, James R} } @article {231, title = {The Alu-rich genomic architecture of SPAST predisposes to diverse and functionally distinct disease-associated CNV alleles.}, journal = {Am J Hum Genet}, volume = {95}, year = {2014}, month = {2014 Aug 07}, pages = {143-61}, abstract = {

Intragenic copy-number variants (CNVs) contribute to the allelic spectrum of both Mendelian and complex disorders. Although pathogenic deletions and duplications in SPAST (mutations in which cause autosomal-dominant spastic paraplegia 4 [SPG4]) have been described, their origins and molecular consequences remain obscure. We mapped breakpoint junctions of 54 SPAST CNVs at nucleotide resolution. Diverse combinations of exons are deleted or duplicated, highlighting the importance of particular exons for spastin function. Of the 54 CNVs, 38 (70\%) appear to be mediated by an Alu-based mechanism, suggesting that the Alu-rich genomic architecture of SPAST renders this locus susceptible to various genome rearrangements. Analysis of breakpoint Alus further informs a model of Alu-mediated CNV formation characterized by small CNV size and potential involvement of mechanisms other than homologous recombination. Twelve deletions (22\%) overlap part of SPAST and a portion of a nearby, directly oriented gene, predicting novel chimeric genes in these subjects{\textquoteright} genomes. cDNA from a subject with a SPAST final exon deletion contained multiple SPAST:SLC30A6 fusion transcripts, indicating that SPAST CNVs can have transcriptional effects beyond the gene itself. SLC30A6 has been implicated in Alzheimer disease, so these fusion gene data could explain a report of spastic paraplegia and dementia cosegregating in a family with deletion of the final exon of SPAST. Our findings provide evidence that the Alu genomic architecture of SPAST predisposes to diverse CNV alleles with distinct transcriptional--and possibly phenotypic--consequences. Moreover, we provide further mechanistic insights into Alu-mediated copy-number change that are extendable to other loci.

}, keywords = {Adenosine Triphosphatases, Alu Elements, Base Sequence, Cation Transport Proteins, Cell Line, Transformed, DNA Copy Number Variations, Genotype, Humans, Protein Isoforms, Recombinant Fusion Proteins, Sequence Analysis, DNA, Sequence Deletion, Spastic Paraplegia, Hereditary, Spastin}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.06.014}, author = {Boone, Philip M and Yuan, Bo and Campbell, Ian M and Scull, Jennifer C and Withers, Marjorie A and Baggett, Brett C and Beck, Christine R and Shaw, Christine J and Stankiewicz, Pawel and Moretti, Paolo and Goodwin, Wendy E and Hein, Nichole and Fink, John K and Seong, Moon-Woo and Seo, Soo Hyun and Park, Sung Sup and Karbassi, Izabela D and Batish, Sat Dev and Ord{\'o}{\~n}ez-Ugalde, Andr{\'e}s and Quint{\'a}ns, Beatriz and Sobrido, Mar{\'\i}a-Jes{\'u}s and Stemmler, Susanne and Lupski, James R} } @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} } @article {229, title = {Parental somatic mosaicism is underrecognized and influences recurrence risk of genomic disorders.}, journal = {Am J Hum Genet}, volume = {95}, year = {2014}, month = {2014 Aug 07}, pages = {173-82}, abstract = {

New human mutations are thought to originate in germ cells, thus making a recurrence of the same mutation in a sibling exceedingly rare. However, increasing sensitivity of genomic technologies has anecdotally revealed mosaicism for mutations in somatic tissues of apparently healthy parents. Such somatically mosaic parents might also have germline mosaicism that can potentially cause unexpected intergenerational recurrences. Here, we show that somatic mosaicism for transmitted mutations among parents of children with simplex genetic disease is more common than currently appreciated. Using the sensitivity of individual-specific breakpoint PCR, we prospectively screened 100 families with children affected by genomic disorders due to rare deletion copy-number variants (CNVs) determined to be de novo by clinical analysis of parental DNA. Surprisingly, we identified four cases of low-level somatic mosaicism for the transmitted CNV in DNA isolated from parental blood. Integrated probabilistic modeling of gametogenesis developed in response to our observations predicts that mutations in parental blood increase recurrence risk substantially more than parental mutations confined to the germline. Moreover, despite the fact that maternally transmitted mutations are the minority of alleles, our model suggests that sexual dimorphisms in gametogenesis result in a greater proportion of somatically mosaic transmitting mothers who are thus at increased risk of recurrence. Therefore, somatic mosaicism together with sexual differences in gametogenesis might explain a considerable fraction of unexpected recurrences of X-linked recessive disease. Overall, our results underscore an important role for somatic mosaicism and mitotic replicative mutational mechanisms in transmission genetics.

}, keywords = {Cell Division, DNA Copy Number Variations, Female, Gametogenesis, Genetic Diseases, Inborn, Genomics, Germ Cells, Germ-Line Mutation, Humans, Male, Models, Genetic, Mosaicism, Mutation, Pedigree, Prospective Studies, Recurrence, Risk, Sex Characteristics, Smith-Magenis Syndrome}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.07.003}, author = {Campbell, Ian M and Yuan, Bo and Robberecht, Caroline and Pfundt, Rolph and Szafranski, Przemyslaw and McEntagart, Meriel E and Nagamani, Sandesh C S and Erez, Ayelet and Bartnik, Magdalena and Wi{\'s}niowiecka-Kowalnik, Barbara and Plunkett, Katie S and Pursley, Amber N and Kang, Sung-Hae L and Bi, Weimin and Lalani, Seema R and Bacino, Carlos A and Vast, Mala and Marks, Karen and Patton, Michael and Olofsson, Peter and Patel, Ankita and Veltman, Joris A and Cheung, Sau Wai and Shaw, Chad A and Vissers, Lisenka E L M and Vermeesch, Joris R and Lupski, James R and Stankiewicz, Pawe{\l}} } @article {301, title = {Deletions of recessive disease genes: CNV contribution to carrier states and disease-causing alleles.}, journal = {Genome Res}, volume = {23}, year = {2013}, month = {2013 Sep}, pages = {1383-94}, abstract = {

Over 1200 recessive disease genes have been described in humans. The prevalence, allelic architecture, and per-genome load of pathogenic alleles in these genes remain to be fully elucidated, as does the contribution of DNA copy-number variants (CNVs) to carrier status and recessive disease. We mined CNV data from 21,470 individuals obtained by array-comparative genomic hybridization in a clinical diagnostic setting to identify deletions encompassing or disrupting recessive disease genes. We identified 3212 heterozygous potential carrier deletions affecting 419 unique recessive disease genes. Deletion frequency of these genes ranged from one occurrence to 1.5\%. When compared with recessive disease genes never deleted in our cohort, the 419 recessive disease genes affected by at least one carrier deletion were longer and located farther from known dominant disease genes, suggesting that the formation and/or prevalence of carrier CNVs may be affected by both local and adjacent genomic features and by selection. Some subjects had multiple carrier CNVs (307 subjects) and/or carrier deletions encompassing more than one recessive disease gene (206 deletions). Heterozygous deletions spanning multiple recessive disease genes may confer carrier status for multiple single-gene disorders, for complex syndromes resulting from the combination of two or more recessive conditions, or may potentially cause clinical phenotypes due to a multiply heterozygous state. In addition to carrier mutations, we identified homozygous and hemizygous deletions potentially causative for recessive disease. We provide further evidence that CNVs contribute to the allelic architecture of both carrier and recessive disease-causing mutations. Thus, a complete recessive carrier screening method or diagnostic test should detect CNV alleles.

}, keywords = {Alleles, Comparative Genomic Hybridization, Databases, Genetic, DNA Copy Number Variations, Gene Deletion, Gene Frequency, Genes, Dominant, Genes, Recessive, Genetic Diseases, Inborn, Homozygote, Humans}, issn = {1549-5469}, doi = {10.1101/gr.156075.113}, author = {Boone, Philip M and Campbell, Ian M and Baggett, Brett C and Soens, Zachry T and Rao, Mitchell M and Hixson, Patricia M and Patel, Ankita and Bi, Weimin and Cheung, Sau Wai and Lalani, Seema R and Beaudet, Arthur L and Stankiewicz, Pawel and Shaw, Chad A and Lupski, James R} } @article {323, title = {Incidental copy-number variants identified by routine genome testing in a clinical population.}, journal = {Genet Med}, volume = {15}, year = {2013}, month = {2013 Jan}, pages = {45-54}, abstract = {

PURPOSE: Mutational load of susceptibility variants has not been studied on a genomic scale in a clinical population, nor has the potential to identify these mutations as incidental findings during clinical testing been systematically ascertained.

METHODS: Array comparative genomic hybridization, a method for genome-wide detection of DNA copy-number variants, was performed clinically on DNA from 9,005 individuals. Copy-number variants encompassing or disrupting single genes were identified and analyzed for their potential to confer predisposition to dominant, adult-onset disease. Multigene copy-number variants affecting dominant, adult-onset cancer syndrome genes were also assessed.

RESULTS: In our cohort, 83 single-gene copy-number variants affected 40 unique genes associated with dominant, adult-onset disorders and unrelated to the patients{\textquoteright} referring diagnoses (i.e., incidental) were found. Fourteen of these copy-number variants are likely disease-predisposing, 25 are likely benign, and 44 are of unknown clinical consequence. When incidental copy-number variants spanning up to 20 genes were considered, 27 copy-number variants affected 17 unique genes associated with dominant, adult-onset cancer predisposition.

CONCLUSION: Copy-number variants potentially conferring susceptibility to adult-onset disease can be identified as incidental findings during routine genome-wide testing. Some of these mutations may be medically actionable, enabling disease surveillance or prevention; however, most incidentally observed single-gene copy-number variants are currently of unclear significance to the patient.

}, keywords = {Age of Onset, Base Sequence, Chromosome Mapping, Comparative Genomic Hybridization, DNA Copy Number Variations, Female, Gene Order, Genetic Predisposition to Disease, Humans, Inheritance Patterns, Male, Reproducibility of Results}, issn = {1530-0366}, doi = {10.1038/gim.2012.95}, author = {Boone, Philip M and Soens, Zachry T and Campbell, Ian M and Stankiewicz, Pawel and Cheung, Sau Wai and Patel, Ankita and Beaudet, Arthur L and Plon, Sharon E and Shaw, Chad A and McGuire, Amy L and Lupski, James R} }