@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 {376, title = {Identification of novel candidate disease genes from de novo exonic copy number variants.}, journal = {Genome Med}, volume = {9}, year = {2017}, month = {2017 09 21}, pages = {83}, abstract = {

BACKGROUND: Exon-targeted microarrays can detect small (<1000~bp) intragenic copy number variants (CNVs), including those that affect only a single exon. This genome-wide high-sensitivity approach increases the molecular diagnosis for conditions with known disease-associated genes, enables better genotype-phenotype correlations, and facilitates variant allele detection allowing novel disease gene discovery.

METHODS: We retrospectively analyzed data from 63,127 patients referred for clinical chromosomal microarray analysis (CMA) at Baylor Genetics laboratories, including 46,755 individuals tested using exon-targeted arrays, from 2007 to 2017. Small CNVs harboring a single gene or two to five non-disease-associated genes were identified; the genes involved were evaluated for a potential disease association.

RESULTS: In this clinical population, among rare CNVs involving any single gene reported in 7200 patients (11\%), we identified 145 de novo autosomal CNVs (117 losses and 28 intragenic gains), 257 X-linked deletion CNVs in males, and 1049 inherited autosomal CNVs (878 losses and 171 intragenic gains); 111 known disease genes were potentially disrupted by de novo autosomal or X-linked (in males) single-gene CNVs. Ninety-one genes, either recently proposed as candidate disease genes or not yet associated with diseases, were disrupted by 147 single-gene CNVs, including 37 de novo deletions and ten de novo intragenic duplications on autosomes and 100 X-linked CNVs in males. Clinical features in individuals with de novo or X-linked CNVs encompassing at most five genes (224~bp to 1.6~Mb in size) were compared to those in individuals with larger-sized deletions (up to 5~Mb in size) in the internal CMA database or loss-of-function single nucleotide variants (SNVs) detected by clinical or research whole-exome sequencing (WES). This enabled the identification of recently published genes (BPTF, NONO, PSMD12, TANGO2, and TRIP12), novel candidate disease genes (ARGLU1 and STK3), and further confirmation of disease association for two recently proposed disease genes (MEIS2 and PTCHD1). Notably, exon-targeted CMA detected several pathogenic single-exon CNVs missed by clinical WES analyses.

CONCLUSIONS: Together, these data document the efficacy of exon-targeted CMA for detection of genic and exonic CNVs, complementing and extending WES in clinical diagnostics, and the potential for discovery of novel disease genes by genome-wide assay.

}, keywords = {Cohort Studies, DNA Copy Number Variations, Exons, Genetic Diseases, Inborn, Genome, Human, Homeodomain Proteins, Humans, Intracellular Signaling Peptides and Proteins, Membrane Proteins, Neurodevelopmental Disorders, Protein-Serine-Threonine Kinases, Retrospective Studies, Transcription Factors, Whole Genome Sequencing}, issn = {1756-994X}, doi = {10.1186/s13073-017-0472-7}, author = {Gambin, Tomasz and Yuan, Bo and Bi, Weimin and Liu, Pengfei and Rosenfeld, Jill A and Coban-Akdemir, Zeynep and Pursley, Amber N and Nagamani, Sandesh C S and Marom, Ronit and Golla, Sailaja and Dengle, Lauren and Petrie, Heather G and Matalon, Reuben and Emrick, Lisa and Proud, Monica B and Treadwell-Deering, Diane and Chao, Hsiao-Tuan and Koillinen, Hannele and Brown, Chester and Urraca, Nora and Mostafavi, Roya and Bernes, Saunder and Roeder, Elizabeth R and Nugent, Kimberly M and Bader, Patricia I and Bellus, Gary and Cummings, Michael and Northrup, Hope and Ashfaq, Myla and Westman, Rachel and Wildin, Robert and Beck, Anita E and Immken, LaDonna and Elton, Lindsay and Varghese, Shaun and Buchanan, Edward and Faivre, Laurence and Lefebvre, Mathilde and Schaaf, Christian P and Walkiewicz, Magdalena and Yang, Yaping and Kang, Sung-Hae L and Lalani, Seema R and Bacino, Carlos A and Beaudet, Arthur L and Breman, Amy M and Smith, Janice L and Cheung, Sau Wai and Lupski, James R and Patel, Ankita and Shaw, Chad A and Stankiewicz, Pawe{\l}} } @article {110, title = {Molecular diagnostic experience of whole-exome sequencing in adult patients.}, journal = {Genet Med}, volume = {18}, year = {2016}, month = {2016 07}, pages = {678-85}, abstract = {

PURPOSE: Whole-exome sequencing (WES) is increasingly used as a diagnostic tool in medicine, but prior reports focus on predominantly pediatric cohorts with neurologic or developmental disorders. We describe the diagnostic yield and characteristics of WES in adults.

METHODS: We performed a retrospective analysis of consecutive WES reports for adults from a diagnostic laboratory. Phenotype composition was determined using Human Phenotype Ontology terms.

RESULTS: Molecular diagnoses were reported for 17.5\% (85/486) of adults, which is lower than that for a primarily pediatric population (25.2\%; P = 0.0003); the diagnostic rate was higher (23.9\%) for those 18-30 years of age compared to patients older than 30 years (10.4\%; P = 0.0001). Dual Mendelian diagnoses contributed to 7\% of diagnoses, revealing blended phenotypes. Diagnoses were more frequent among individuals with abnormalities of the nervous system, skeletal system, head/neck, and growth. Diagnostic rate was independent of family history information, and de novo mutations contributed to 61.4\% of autosomal dominant diagnoses.

CONCLUSION: Early WES experience in adults demonstrates molecular diagnoses in a substantial proportion of patients, informing clinical management, recurrence risk, and recommendations for relatives. A positive family history was not predictive, consistent with molecular diagnoses often revealed by de novo events, informing the Mendelian basis of genetic disease in adults.Genet Med 18 7, 678-685.

}, keywords = {Adult, Exome, Female, Genetic Diseases, Inborn, Genetic Predisposition to Disease, Genetic Testing, Genome, Human, High-Throughput Nucleotide Sequencing, Humans, Male, Pathology, Molecular}, issn = {1530-0366}, doi = {10.1038/gim.2015.142}, author = {Posey, Jennifer E and Rosenfeld, Jill A and James, Regis A and Bainbridge, Matthew and Niu, Zhiyv and Wang, Xia and Dhar, Shweta and Wiszniewski, Wojciech and Akdemir, Zeynep H C and Gambin, Tomasz and Xia, Fan and Person, Richard E and Walkiewicz, Magdalena and Shaw, Chad A and Sutton, V Reid and Beaudet, Arthur L and Muzny, Donna and Eng, Christine M and Yang, Yaping and Gibbs, Richard A and Lupski, James R and Boerwinkle, Eric and Plon, Sharon E} } @article {102, title = {Multiallelic Positions in the Human Genome: Challenges for Genetic Analyses.}, journal = {Hum Mutat}, volume = {37}, year = {2016}, month = {2016 Mar}, pages = {231-234}, abstract = {

As the amount of human genomic sequence available from personal genomes and exomes has increased, so too has the observation of genomic positions having two or more alternative alleles, so-called multiallelic sites. For portions of the haploid genome that are present in more than one copy, including segmental duplications, variation at such multisite variant positions becomes even more complex. Despite the frequency of multiallelic variants, a number of commonly used resources and tools in genomic research and diagnostics do not support these multiallelic variants all together or require special modifications. Here, we explore the frequency of multiallelic sites in large samples with whole exome sequencing and discuss potential outcomes of failing to account for multiple variant alleles. We also briefly discuss some commonly utilized resources that fully support multiallelic sites.

}, keywords = {Alleles, Exome, Genome, Human, Humans}, issn = {1098-1004}, doi = {10.1002/humu.22944}, author = {Campbell, Ian M and Gambin, Tomasz and Jhangiani, Shalini and Grove, Megan L and Veeraraghavan, Narayanan and Muzny, Donna M and Shaw, Chad A and Gibbs, Richard A and Boerwinkle, Eric and Yu, Fuli 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 {169, title = {Somatic mosaicism: implications for disease and transmission genetics.}, journal = {Trends Genet}, volume = {31}, year = {2015}, month = {2015 Jul}, pages = {382-92}, abstract = {

Nearly all of the genetic material among cells within an organism is identical. However, single-nucleotide variants (SNVs), small insertions/deletions (indels), copy-number variants (CNVs), and other structural variants (SVs) continually accumulate as cells divide during development. This process results in an organism composed of countless cells, each with its own unique personal genome. Thus, every human is undoubtedly mosaic. Mosaic mutations can go unnoticed, underlie genetic disease or normal human variation, and may be transmitted to the next generation as constitutional variants. We review the influence of the developmental timing of mutations, the mechanisms by which they arise, methods for detecting mosaic variants, and the risk of passing these mutations on to the next generation.

}, keywords = {Animals, Genetic Diseases, Inborn, Genome, Human, Humans, Mosaicism, Mutagenesis, Insertional, Mutation, Polymorphism, Single Nucleotide, Risk, Trinucleotide Repeat Expansion}, issn = {0168-9525}, doi = {10.1016/j.tig.2015.03.013}, author = {Campbell, Ian M and Shaw, Chad A and Stankiewicz, Pawel and Lupski, James R} }