1
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Zhang Y, Wei WB, Zhao J, Xu X, Wang F. Spectrum and tissue distribution of RB1 pathogenic alleles in mosaic retinoblastoma patients. Ophthalmic Genet 2022; 43:795-805. [PMID: 35938543 DOI: 10.1080/13816810.2022.2098985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To characterize the spectrum of mosaic RB1 pathogenic alleles and map the distribution of mutant cells in available tissues from mosaic patients. Next-generation sequencing was performed on blood samples from 263 retinoblastoma families to identify mosaic RB1 variant alleles. A variety of available tissues were sampled to determine tissue distribution and fraction of mutant cells in five mosaic patients who consented to participate in mosaic pathogenic allele research. Twelve identified mosaic RB1 variants were all "null" pathogenic alleles and displayed reduced expressivity. The use of next-generation deep sequencing increased the sensitivity of mosaicism detection to 0.03% in the case of tissue DNA. In the five mosaic participants, we observed coherent but uneven, bilateral asymmetrical distribution of mutant cells across various tissues. They all carried early-embryonic mosaic pathogenic alleles and had significantly higher variant fractions in blood than in other tissues. Variant fractions of ipsilateral tissue samples were not concordant higher or lower compared with the contralateral side. Only ipsilateral conjunctival and oral epithelial cells showed concordance in mosaicism levels. No associations were observed between the laterality of affected eyes and variant fractions of any tissue type. NGS allows the detection of low-level mosaicism. Mosaic RB1 pathogenic alleles are prone to occur at very early stages of human embryonic development. With respect to genetic counseling, risk prediction should take into account unrecognized mosaicism. The underlying tissue distribution patterns of mosaic RB1 variant alleles remain to be determined.
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Affiliation(s)
- Yan Zhang
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Wen-Bin Wei
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Junyang Zhao
- Department of Ophthalmology, Pediatric Oncology Center, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Xiaolin Xu
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Fufeng Wang
- Nanjing Geneseeq Technology Inc, Nanjing, China
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2
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Zemet R, Van den Veyver IB, Stankiewicz P. Parental mosaicism for apparent de novo genetic variants: Scope, detection, and counseling challenges. Prenat Diagn 2022; 42:811-821. [PMID: 35394072 PMCID: PMC9995893 DOI: 10.1002/pd.6144] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 04/04/2022] [Accepted: 04/04/2022] [Indexed: 11/07/2022]
Abstract
The disease burden of de novo mutations (DNMs) has been evidenced only recently when the common application of next-generation sequencing technologies enabled their reliable and affordable detection through family-based clinical exome or genome sequencing. Implementation of exome sequencing into prenatal diagnostics revealed that up to 63% of pathogenic or likely pathogenic variants associated with fetal structural anomalies are apparently de novo, primarily for autosomal dominant disorders. Apparent DNMs have been considered to primarily occur as germline or zygotic events, with consequently negligible recurrence risks. However, there is now evidence that a considerable proportion of them are in fact inherited from a parent mosaic for the variant. Here, we review the burden of DNMs in prenatal diagnostics and the influence of parental mosaicism on the interpretation of apparent DNMs and discuss the challenges with detecting and quantifying parental mosaicism and its effect on recurrence risk. We also describe new bioinformatic and technological tools developed to assess mosaicism and discuss how they improve the accuracy of reproductive risk counseling when parental mosaicism is detected.
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Affiliation(s)
- Roni Zemet
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Ignatia B Van den Veyver
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas, USA.,Texas Children's Hospital, Houston, Texas, USA
| | - Paweł Stankiewicz
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
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3
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Lupski JR. Clan genomics: From OMIM phenotypic traits to genes and biology. Am J Med Genet A 2021; 185:3294-3313. [PMID: 34405553 PMCID: PMC8530976 DOI: 10.1002/ajmg.a.62434] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/29/2021] [Accepted: 07/04/2021] [Indexed: 12/20/2022]
Abstract
Clinical characterization of a patient phenotype has been the quintessential approach for elucidating a differential diagnosis and a hypothesis to explore a potential clinical diagnosis. This has resulted in a language of medicine and a semantic ontology, with both specialty- and subspecialty-specific lexicons, that can be challenging to translate and interpret. There is no 'Rosetta Stone' of clinical medicine such as the genetic code that can assist translation and interpretation of the language of genetics. Nevertheless, the information content embodied within a clinical diagnosis can guide management, therapeutic intervention, and potentially prognostic outlook of disease enabling anticipatory guidance for patients and families. Clinical genomics is now established firmly in medical practice. The granularity and informative content of a personal genome is immense. Yet, we are limited in our utility of much of that personal genome information by the lack of functional characterization of the overwhelming majority of computationally annotated genes in the haploid human reference genome sequence. Whereas DNA and the genetic code have provided a 'Rosetta Stone' to translate genetic variant information, clinical medicine, and clinical genomics provide the context to understand human biology and disease. A path forward will integrate deep phenotyping, such as available in a clinical synopsis in the Online Mendelian Inheritance in Man (OMIM) entries, with personal genome analyses.
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Affiliation(s)
- James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Hospital, Houston, Texas, USA
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4
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Sandal P, Jong CJ, Merrill RA, Song J, Strack S. Protein phosphatase 2A - structure, function and role in neurodevelopmental disorders. J Cell Sci 2021; 134:270819. [PMID: 34228795 DOI: 10.1242/jcs.248187] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Neurodevelopmental disorders (NDDs), including intellectual disability (ID), autism and schizophrenia, have high socioeconomic impact, yet poorly understood etiologies. A recent surge of large-scale genome or exome sequencing studies has identified a multitude of mostly de novo mutations in subunits of the protein phosphatase 2A (PP2A) holoenzyme that are strongly associated with NDDs. PP2A is responsible for at least 50% of total Ser/Thr dephosphorylation in most cell types and is predominantly found as trimeric holoenzymes composed of catalytic (C), scaffolding (A) and variable regulatory (B) subunits. PP2A can exist in nearly 100 different subunit combinations in mammalian cells, dictating distinct localizations, substrates and regulatory mechanisms. PP2A is well established as a regulator of cell division, growth, and differentiation, and the roles of PP2A in cancer and various neurodegenerative disorders, such as Alzheimer's disease, have been reviewed in detail. This Review summarizes and discusses recent reports on NDDs associated with mutations of PP2A subunits and PP2A-associated proteins. We also discuss the potential impact of these mutations on the structure and function of the PP2A holoenzymes and the etiology of NDDs.
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Affiliation(s)
- Priyanka Sandal
- Department of Neuroscience and Pharmacology, and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242, USA
| | - Chian Ju Jong
- Department of Neuroscience and Pharmacology, and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242, USA
| | - Ronald A Merrill
- Department of Neuroscience and Pharmacology, and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242, USA
| | - Jianing Song
- Department of Neuroscience and Pharmacology, and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242, USA
| | - Stefan Strack
- Department of Neuroscience and Pharmacology, and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242, USA
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5
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Evaluating the Role of MAST1 as an Intellectual Disability Disease Gene: Identification of a Novel De Novo Variant in a Patient with Developmental Disabilities. J Mol Neurosci 2021; 70:320-327. [PMID: 31721002 DOI: 10.1007/s12031-019-01415-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Intellectual disability (ID) is one of the most common developmental disorders characterized by a congenital limitation in intellectual functioning and adaptive behavior. More than 800 genes have been implicated so far in the pathogenesis of syndromic and non-syndromic ID conditions with the actual number is expected to be over two thousand. The advent of next-generation sequencing resulted in the identification of many novel ID genes with new genes are being reported on weekly basis. The level of evidence on ID genes varies with some of them being preliminary. MAST1 have been hinted at as being causative of ID but the evidence has been very sketchy. Extensive search of the literature identified three heterozygous de novo missense variants in MAST1 as possible causes of syndromic ID in three individuals where intellectual disability has been a major feature. Using exome sequencing, we identified a novel missense variant c.3539T>G, p.(Leu1180Arg) in MAST1 in an Emirati patient with intellectual disability, microcephaly, and dysmorphic features. In silico pathogenicity prediction analyses predict that all the four missense variants reported in this study are likely to be damaging. Immunostaining of cells expressing human MAST1 showed that majority large proportion of the expressed protein is colocalized the microtubule filaments in the cytoplasm. However, the identified variant c.3539T>G, p.(Leu1180Arg) as well as the other three variants seem to localize in a similar pattern to wild-type indicating a disease mechanism not involving mis-targeting. We, therefore, suggest that mutations in MAST1 should be considered as strong candidates for intellectual disability in humans.
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6
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Posey JE, O'Donnell-Luria AH, Chong JX, Harel T, Jhangiani SN, Coban Akdemir ZH, Buyske S, Pehlivan D, Carvalho CMB, Baxter S, Sobreira N, Liu P, Wu N, Rosenfeld JA, Kumar S, Avramopoulos D, White JJ, Doheny KF, Witmer PD, Boehm C, Sutton VR, Muzny DM, Boerwinkle E, Günel M, Nickerson DA, Mane S, MacArthur DG, Gibbs RA, Hamosh A, Lifton RP, Matise TC, Rehm HL, Gerstein M, Bamshad MJ, Valle D, Lupski JR. Insights into genetics, human biology and disease gleaned from family based genomic studies. Genet Med 2019; 21:798-812. [PMID: 30655598 PMCID: PMC6691975 DOI: 10.1038/s41436-018-0408-7] [Citation(s) in RCA: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 12/05/2018] [Indexed: 12/16/2022] Open
Abstract
Identifying genes and variants contributing to rare disease phenotypes and Mendelian conditions informs biology and medicine, yet potential phenotypic consequences for variation of >75% of the ~20,000 annotated genes in the human genome are lacking. Technical advances to assess rare variation genome-wide, particularly exome sequencing (ES), enabled establishment in the United States of the National Institutes of Health (NIH)-supported Centers for Mendelian Genomics (CMGs) and have facilitated collaborative studies resulting in novel "disease gene" discoveries. Pedigree-based genomic studies and rare variant analyses in families with suspected Mendelian conditions have led to the elucidation of hundreds of novel disease genes and highlighted the impact of de novo mutational events, somatic variation underlying nononcologic traits, incompletely penetrant alleles, phenotypes with high locus heterogeneity, and multilocus pathogenic variation. Herein, we highlight CMG collaborative discoveries that have contributed to understanding both rare and common diseases and discuss opportunities for future discovery in single-locus Mendelian disorder genomics. Phenotypic annotation of all human genes; development of bioinformatic tools and analytic methods; exploration of non-Mendelian modes of inheritance including reduced penetrance, multilocus variation, and oligogenic inheritance; construction of allelic series at a locus; enhanced data sharing worldwide; and integration with clinical genomics are explored. Realizing the full contribution of rare disease research to functional annotation of the human genome, and further illuminating human biology and health, will lay the foundation for the Precision Medicine Initiative.
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Affiliation(s)
- Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
| | - Anne H O'Donnell-Luria
- Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Boston Children's Hospital, Boston, MA, USA
| | - Jessica X Chong
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Tamar Harel
- Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Shalini N Jhangiani
- The Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Zeynep H Coban Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Steven Buyske
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
- Department of Statistics, Rutgers University, Piscataway, NJ, USA
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Claudia M B Carvalho
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Samantha Baxter
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Nara Sobreira
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Baylor Genetics Laboratory, Houston, TX, USA
| | - Nan Wu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Orthopedic Surgery, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Sushant Kumar
- Computational Biology and Bioinformatics Program, Yale University Medical School, New Haven, CT, USA
| | - Dimitri Avramopoulos
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Janson J White
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Kimberly F Doheny
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
- Center for Inherited Disease Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - P Dane Witmer
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
- Center for Inherited Disease Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Corinne Boehm
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - V Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Donna M Muzny
- The Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Eric Boerwinkle
- The Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
- Human Genetics Center, University of Texas Health Science Center, Houston, TX, USA
| | - Murat Günel
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA
- Department of Genetics, Yale School of Medicine, New Haven, CT, USA
| | | | - Shrikant Mane
- Yale Center for Genome Analysis, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Daniel G MacArthur
- Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- The Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Ada Hamosh
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Richard P Lifton
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
- Laboratory of Human Genetics and Genomics, The Rockefeller University, New York, NY, USA
| | - Tara C Matise
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
| | - Heidi L Rehm
- Analytic and Translational Genetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Mark Gerstein
- Computational Biology and Bioinformatics Program, Yale University Medical School, New Haven, CT, USA
| | - Michael J Bamshad
- Department of Pediatrics, University of Washington, Seattle, WA, USA
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - David Valle
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- The Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA.
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
- Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA.
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7
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Abstract
The precise location of variants in the human genome is of utmost importance. We present a unique approach, coverage-based single nucleotide variant (SNV) identification (COBASI), which uses only perfect matches between the reads of a sequence project and a reference genome to detect and accurately identify de novo SNVs. From the perfect matches, a representation of the read coverage per nucleotide along the genome, the variation landscape, is generated. SNVs are then pinpointed as significant changes in coverage and de novo SNVs can be identified with high precision. The performance of COBASI was analyzed using simulations and experimentally validated by sequencing de novo SNVs identified from a parent–offspring trio. We propose this pipeline as a useful tool for different genomic applications. The precise determination of de novo genetic variants has enormous implications across different fields of biology and medicine, particularly personalized medicine. Currently, de novo variations are identified by mapping sample reads from a parent–offspring trio to a reference genome, allowing for a certain degree of differences. While widely used, this approach often introduces false-positive (FP) results due to misaligned reads and mischaracterized sequencing errors. In a previous study, we developed an alternative approach to accurately identify single nucleotide variants (SNVs) using only perfect matches. However, this approach could be applied only to haploid regions of the genome and was computationally intensive. In this study, we present a unique approach, coverage-based single nucleotide variant identification (COBASI), which allows the exploration of the entire genome using second-generation short sequence reads without extensive computing requirements. COBASI identifies SNVs using changes in coverage of exactly matching unique substrings, and is particularly suited for pinpointing de novo SNVs. Unlike other approaches that require population frequencies across hundreds of samples to filter out any methodological biases, COBASI can be applied to detect de novo SNVs within isolated families. We demonstrate this capability through extensive simulation studies and by studying a parent–offspring trio we sequenced using short reads. Experimental validation of all 58 candidate de novo SNVs and a selection of non-de novo SNVs found in the trio confirmed zero FP calls. COBASI is available as open source at https://github.com/Laura-Gomez/COBASI for any researcher to use.
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8
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Gambin T, Yuan B, Bi W, Liu P, Rosenfeld JA, Coban-Akdemir Z, Pursley AN, Nagamani SCS, Marom R, Golla S, Dengle L, Petrie HG, Matalon R, Emrick L, Proud MB, Treadwell-Deering D, Chao HT, Koillinen H, Brown C, Urraca N, Mostafavi R, Bernes S, Roeder ER, Nugent KM, Bader PI, Bellus G, Cummings M, Northrup H, Ashfaq M, Westman R, Wildin R, Beck AE, Immken L, Elton L, Varghese S, Buchanan E, Faivre L, Lefebvre M, Schaaf CP, Walkiewicz M, Yang Y, Kang SHL, Lalani SR, Bacino CA, Beaudet AL, Breman AM, Smith JL, Cheung SW, Lupski JR, Patel A, Shaw CA, Stankiewicz P. Identification of novel candidate disease genes from de novo exonic copy number variants. Genome Med 2017; 9:83. [PMID: 28934986 PMCID: PMC5607840 DOI: 10.1186/s13073-017-0472-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 09/01/2017] [Indexed: 12/21/2022] Open
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.
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Affiliation(s)
- Tomasz Gambin
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Institute of Computer Science, Warsaw University of Technology, Warsaw, 00-665, Poland.,Department of Medical Genetics, Institute of Mother and Child, Warsaw, 01-211, Poland
| | - Bo Yuan
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Weimin Bi
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA
| | - Zeynep Coban-Akdemir
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA
| | - Amber N Pursley
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA
| | - Sandesh C S Nagamani
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA
| | - Ronit Marom
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA
| | - Sailaja Golla
- Division of Pediatric Neurology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Lauren Dengle
- Division of Pediatric Neurology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | | | - Reuben Matalon
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, 77555, USA.,Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Lisa Emrick
- Department of Pediatric, Section of Child Neurology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Monica B Proud
- Department of Pediatric, Section of Child Neurology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Diane Treadwell-Deering
- Department of Psychiatry and Behavioral Sciences, Child and Adolescent Psychiatry Division, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Hsiao-Tuan Chao
- Department of Pediatric, Section of Child Neurology, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, 77030, USA
| | - Hannele Koillinen
- Department of Clinical Genetics, Helsinki University Hospital, Helsinki, 00029, Finland
| | - Chester Brown
- Genetics Division, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, 38105, USA.,Le Bonheur Children's Hospital, Memphis, TN, 38103, USA
| | - Nora Urraca
- Le Bonheur Children's Hospital, Memphis, TN, 38103, USA
| | | | | | - Elizabeth R Roeder
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Department of Pediatrics, Baylor College of Medicine, San Antonio, TX, 78207, USA
| | - Kimberly M Nugent
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Department of Pediatrics, Baylor College of Medicine, San Antonio, TX, 78207, USA
| | - Patricia I Bader
- Northeast Indiana Genetic Counseling Center, Wayne, IN, 46804, USA
| | - Gary Bellus
- Section of Clinical Genetics & Metabolism, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Michael Cummings
- Department of Psychiatry Erie County Medical Center, Buffalo, NY, 14215, USA
| | - Hope Northrup
- Division of Medical Genetics, Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Myla Ashfaq
- Division of Medical Genetics, Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | | | - Robert Wildin
- St. Luke's Children's Hospital, Boise, ID, 83702, USA.,The National Human Genome Research Institute, Bethesda, MD, 20892, USA
| | - Anita E Beck
- Seattle Children's Hospital, Seattle, WA, 98105, USA.,Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA, 98195, USA
| | | | - Lindsay Elton
- Child Neurology Consultants of Austin, Austin, TX, 78731, USA
| | - Shaun Varghese
- THINK Neurology for Kids/Children's Memorial Hermann Hospital, The Woodlands, TX, 77380, USA
| | - Edward Buchanan
- Division of Plastic Surgery, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Laurence Faivre
- Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs de l'Est, FHU-TRANSLAD, CHU Dijon, Dijon, France
| | - Mathilde Lefebvre
- Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs de l'Est, FHU-TRANSLAD, CHU Dijon, Dijon, France
| | - Christian P Schaaf
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, 77030, USA
| | - Magdalena Walkiewicz
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Yaping Yang
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Sung-Hae L Kang
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Seema R Lalani
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Carlos A Bacino
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Arthur L Beaudet
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Amy M Breman
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Janice L Smith
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Sau Wai Cheung
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA.,Texas Children's Hospital, Houston, TX, 77030, USA
| | - Ankita Patel
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Chad A Shaw
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA.,Baylor Genetics, Houston, TX, 77021, USA
| | - Paweł Stankiewicz
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030-3411, USA. .,Baylor Genetics, Houston, TX, 77021, USA.
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9
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Acuna-Hidalgo R, Veltman JA, Hoischen A. New insights into the generation and role of de novo mutations in health and disease. Genome Biol 2016; 17:241. [PMID: 27894357 PMCID: PMC5125044 DOI: 10.1186/s13059-016-1110-1] [Citation(s) in RCA: 276] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Aside from inheriting half of the genome of each of our parents, we are born with a small number of novel mutations that occurred during gametogenesis and postzygotically. Recent genome and exome sequencing studies of parent-offspring trios have provided the first insights into the number and distribution of these de novo mutations in health and disease, pointing to risk factors that increase their number in the offspring. De novo mutations have been shown to be a major cause of severe early-onset genetic disorders such as intellectual disability, autism spectrum disorder, and other developmental diseases. In fact, the occurrence of novel mutations in each generation explains why these reproductively lethal disorders continue to occur in our population. Recent studies have also shown that de novo mutations are predominantly of paternal origin and that their number increases with advanced paternal age. Here, we review the recent literature on de novo mutations, covering their detection, biological characterization, and medical impact.
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Affiliation(s)
- Rocio Acuna-Hidalgo
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands
| | - Joris A Veltman
- Department of Human Genetics, Donders Institute of Neuroscience, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands.
- Department of Clinical Genetics, GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, Universiteitssingel 50, 6229 ER, Maastricht, The Netherlands.
| | - Alexander Hoischen
- Department of Human Genetics, Donders Institute of Neuroscience, Radboud University Medical Center, Geert Grooteplein 10, 6525 GA, Nijmegen, The Netherlands
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10
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Masumura K, Toyoda-Hokaiwado N, Ukai A, Gondo Y, Honma M, Nohmi T. Dose-dependent de novo germline mutations detected by whole-exome sequencing in progeny of ENU-treated male gpt delta mice. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2016; 810:30-39. [DOI: 10.1016/j.mrgentox.2016.09.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 09/20/2016] [Accepted: 09/27/2016] [Indexed: 01/06/2023]
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11
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Yauk CL, Lambert IB, Meek MEB, Douglas GR, Marchetti F. Development of the adverse outcome pathway "alkylation of DNA in male premeiotic germ cells leading to heritable mutations" using the OECD's users' handbook supplement. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2015; 56:724-750. [PMID: 26010389 DOI: 10.1002/em.21954] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 03/31/2015] [Accepted: 04/01/2015] [Indexed: 06/04/2023]
Abstract
The Organisation for Economic Cooperation and Development's (OECD) Adverse Outcome Pathway (AOP) programme aims to develop a knowledgebase of all known pathways of toxicity that lead to adverse effects in humans and ecosystems. A Users' Handbook was recently released to provide supplementary guidance on AOP development. This article describes one AOP-alkylation of DNA in male premeiotic germ cells leading to heritable mutations. This outcome is an important regulatory endpoint. The AOP describes the biological plausibility and empirical evidence supporting that compounds capable of alkylating DNA cause germ cell mutations and subsequent mutations in the offspring of exposed males. Alkyl adducts are subject to DNA repair; however, at high doses the repair machinery becomes saturated. Lack of repair leads to replication of alkylated DNA and ensuing mutations in male premeiotic germ cells. Mutations that do not impair spermatogenesis persist and eventually are present in mature sperm. Thus, the mutations are transmitted to the offspring. Although there are some gaps in empirical support and evidence for essentiality of the key events for certain aspects of this AOP, the overall AOP is generally accepted as dogma and applies broadly to any species that produces sperm. The AOP was developed and used in an iterative process to test and refine the Users' Handbook, and is one of the first publicly available AOPs. It is our hope that this AOP will be leveraged to develop other AOPs in this field to advance method development, computational models to predict germ cell effects, and integrated testing strategies.
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Affiliation(s)
- Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Iain B Lambert
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - M E Bette Meek
- R. Samuel McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Ontario, Canada
| | - George R Douglas
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
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12
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Dillon LW, Kumar P, Shibata Y, Wang YH, Willcox S, Griffith JD, Pommier Y, Takeda S, Dutta A. Production of Extrachromosomal MicroDNAs Is Linked to Mismatch Repair Pathways and Transcriptional Activity. Cell Rep 2015; 11:1749-59. [PMID: 26051933 DOI: 10.1016/j.celrep.2015.05.020] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 04/20/2015] [Accepted: 05/11/2015] [Indexed: 12/15/2022] Open
Abstract
MicroDNAs are <400-base extrachromosomal circles found in mammalian cells. Tens of thousands of microDNAs have been found in all tissue types, including sperm. MicroDNAs arise preferentially from areas with high gene density, GC content, and exon density from promoters with activating chromatin modifications and in sperm from the 5'-UTR of full-length LINE-1 elements, but are depleted from lamin-associated heterochromatin. Analysis of microDNAs from a set of human cancer cell lines revealed lineage-specific patterns of microDNA origins. A survey of microDNAs from chicken cells defective in various DNA repair proteins reveals that homologous recombination and non-homologous end joining repair pathways are not required for microDNA production. Deletion of the MSH3 DNA mismatch repair protein results in a significant decrease in microDNA abundance, specifically from non-CpG genomic regions. Thus, microDNAs arise as part of normal cellular physiology—either from DNA breaks associated with RNA metabolism or from replication slippage followed by mismatch repair.
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Affiliation(s)
- Laura W Dillon
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Pankaj Kumar
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Yoshiyuki Shibata
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Yuh-Hwa Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Smaranda Willcox
- Lineberger Comprehensive Cancer Center, Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27514, USA
| | - Jack D Griffith
- Lineberger Comprehensive Cancer Center, Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27514, USA
| | - Yves Pommier
- Laboratory of Molecular Pharmacology and Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA
| | - Shunichi Takeda
- CREST Research Project, Japan Science and Technology Corporation, Radiation Genetics, Faculty of Medicine, Kyoto University, Konoe Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Anindya Dutta
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
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13
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Yauk CL, Aardema MJ, Benthem JV, Bishop JB, Dearfield KL, DeMarini DM, Dubrova YE, Honma M, Lupski JR, Marchetti F, Meistrich ML, Pacchierotti F, Stewart J, Waters MD, Douglas GR. Approaches for identifying germ cell mutagens: Report of the 2013 IWGT workshop on germ cell assays(☆). MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 783:36-54. [PMID: 25953399 DOI: 10.1016/j.mrgentox.2015.01.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 01/23/2015] [Indexed: 01/06/2023]
Abstract
This workshop reviewed the current science to inform and recommend the best evidence-based approaches on the use of germ cell genotoxicity tests. The workshop questions and key outcomes were as follows. (1) Do genotoxicity and mutagenicity assays in somatic cells predict germ cell effects? Limited data suggest that somatic cell tests detect most germ cell mutagens, but there are strong concerns that dictate caution in drawing conclusions. (2) Should germ cell tests be done, and when? If there is evidence that a chemical or its metabolite(s) will not reach target germ cells or gonadal tissue, it is not necessary to conduct germ cell tests, notwithstanding somatic outcomes. However, it was recommended that negative somatic cell mutagens with clear evidence for gonadal exposure and evidence of toxicity in germ cells could be considered for germ cell mutagenicity testing. For somatic mutagens that are known to reach the gonadal compartments and expose germ cells, the chemical could be assumed to be a germ cell mutagen without further testing. Nevertheless, germ cell mutagenicity testing would be needed for quantitative risk assessment. (3) What new assays should be implemented and how? There is an immediate need for research on the application of whole genome sequencing in heritable mutation analysis in humans and animals, and integration of germ cell assays with somatic cell genotoxicity tests. Focus should be on environmental exposures that can cause de novo mutations, particularly newly recognized types of genomic changes. Mutational events, which may occur by exposure of germ cells during embryonic development, should also be investigated. Finally, where there are indications of germ cell toxicity in repeat dose or reproductive toxicology tests, consideration should be given to leveraging those studies to inform of possible germ cell genotoxicity.
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Affiliation(s)
- Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada.
| | | | - Jan van Benthem
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Jack B Bishop
- National Institute of Environmental Health Sciences, NC, USA
| | | | | | | | | | - James R Lupski
- Department of Molecular and Human Genetics, and Department of Pediatrics, Baylor College of Medicine, USA
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | | | - Francesca Pacchierotti
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Italy
| | | | | | - George R Douglas
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada.
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14
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Copy number variation distribution in six monozygotic twin pairs discordant for schizophrenia. Twin Res Hum Genet 2014; 17:108-20. [PMID: 24556202 DOI: 10.1017/thg.2014.6] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have evaluated copy number variants (CNVs) in six monozygotic twin pairs discordant for schizophrenia. The data from Affymetrix® Human SNP 6.0 arrays™ were analyzed using Affymetrix® Genotyping Console™, Partek® Genomics Suite™, PennCNV, and Golden Helix SVS™. This yielded both program-specific and overlapping results. Only CNVs called by Affymetrix Genotyping Console, Partek Genomics Suite, and PennCNV were used in further analysis. This analysis included an assessment of calls in each of the six twin pairs towards identification of unique CNVs in affected and unaffected co-twins. Real time polymerase chain reaction (PCR) experiments confirmed one CNV loss at 7q11.21 that was found in the affected patient but not in the unaffected twin. The results identified CNVs and genes that were previously implicated in mental abnormalities in four of the six twin pairs. It included PYY (twin pairs 1 and 5), EPHA3 (twin pair 3), KIAA1211L (twin pair 4), and GPR139 (twin pair 5). They represent likely candidate genes and CNVs for the discordance of four of the six monozygotic twin pairs for this heterogeneous neurodevelopmental disorder. An explanation for these differences is ontogenetic de novo events that differentiate in the monozygotic twins during development.
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15
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Kumar K, Maiti S, Castellani CA, O'Reilly R, Singh SM. A novel deletion cluster at 13q14.2-q21.33 in an 80-year man with late onset leukemia: Clinical and molecular findings. INDIAN JOURNAL OF HUMAN GENETICS 2013; 19:96-100. [PMID: 23901202 PMCID: PMC3722640 DOI: 10.4103/0971-6866.112916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chromosomal deletions are among the most common genetic events observed in hematologic malignancies; loss of genetic material is regarded as a hallmark of putative tumor suppressor gene localization. We have identified an unusual cluster of deletions at 13q14.2-13q21.33 in an 80-year-old father of a monozygotic twin pair discordant for schizophrenia, who developed chronic leukemia (CLL) at age 69. MATERIALS AND METHODS: The breakpoints for individual deletions in this cluster was identified by Affymetrix Human Array 6.0 screening. RESULTS: The deleted segments harbours a number of genes, most associated with cancer as well as a high concentration of LINEs, SINEs and related repeats. The derived chromosome represents an intra-chromosomal re-arrangement that quickly overtook blood progenitor cells probably before age 69 as a cause of CLL. CONCLUSIONS: The study highlights the role of ongoing de novo changes at susceptible sites, such as repeat rich regions, in the human genome. Also, it argues for the involvement of genes/deletions in the 13q(14.2-21.33) region in the development of CCL.
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Affiliation(s)
- Kiran Kumar
- Department of Biology, Molecular Genetics Unit, The University of Western Ontario, London, ON, Canada
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16
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Sun Z, Liu P, Jia X, Withers MA, Jin L, Lupski JR, Zhang F. Replicative mechanisms of CNV formation preferentially occur as intrachromosomal events: evidence from Potocki-Lupski duplication syndrome. Hum Mol Genet 2012; 22:749-56. [PMID: 23161748 DOI: 10.1093/hmg/dds482] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Copy number variations (CNVs) in the human genome contribute significantly to disease. De novo CNV mutations arise via genomic rearrangements, which can occur in 'trans', i.e. via interchromosomal events, or in 'cis', i.e. via intrachromosomal events. However, what molecular mechanisms occur between chromosomes versus between or within chromatids has not been systematically investigated. We hypothesized that distinct CNV mutational mechanisms, based on their intrinsic properties, may occur in a biased intrachromosomal versus interchromosomal manner. Here, we studied 62 genomic duplications observed in association with sporadic Potocki-Lupski syndrome (PTLS), in which multiple mutational mechanisms appear to be operative. Intriguingly, more interchromosomal than intrachromosomal events were identified in recurrent PTLS duplications mediated by non-allelic homologous recombination, whereas the reciprocal distribution was found for replicative mechanisms and non-homologous end-joining, likely reflecting the differences in spacial proximity of homologous chromosomes during different mutational processes.
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Affiliation(s)
- Zhe Sun
- State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai 200433, China
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17
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Abstract
In the past decade, we have witnessed a flood of reports about mutations that cause or contribute to intellectual disability (ID). This rapid progress has been driven in large part by the implementation of chromosomal microarray analysis and next-generation sequencing methods. The findings have revealed extensive genetic heterogeneity for ID, as well as examples of a common genetic etiology for ID and other neurobehavioral/psychiatric phenotypes. Clinical diagnostic application of these new findings is already well under way, despite incomplete understanding of non-Mendelian transmission patterns that are sometimes observed.
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Affiliation(s)
- Jay W Ellison
- Signature Genomic Laboratories, PerkinElmer, Inc., Spokane, Washington 99207, USA.
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18
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Yauk CL, Lucas Argueso J, Auerbach SS, Awadalla P, Davis SR, DeMarini DM, Douglas GR, Dubrova YE, Elespuru RK, Glover TW, Hales BF, Hurles ME, Klein CB, Lupski JR, Manchester DK, Marchetti F, Montpetit A, Mulvihill JJ, Robaire B, Robbins WA, Rouleau GA, Shaughnessy DT, Somers CM, Taylor JG, Trasler J, Waters MD, Wilson TE, Witt KL, Bishop JB. Harnessing genomics to identify environmental determinants of heritable disease. Mutat Res 2012; 752:6-9. [PMID: 22935230 DOI: 10.1016/j.mrrev.2012.08.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 08/17/2012] [Accepted: 08/19/2012] [Indexed: 12/27/2022]
Abstract
Next-generation sequencing technologies can now be used to directly measure heritable de novo DNA sequence mutations in humans. However, these techniques have not been used to examine environmental factors that induce such mutations and their associated diseases. To address this issue, a working group on environmentally induced germline mutation analysis (ENIGMA) met in October 2011 to propose the necessary foundational studies, which include sequencing of parent-offspring trios from highly exposed human populations, and controlled dose-response experiments in animals. These studies will establish background levels of variability in germline mutation rates and identify environmental agents that influence these rates and heritable disease. Guidance for the types of exposures to examine come from rodent studies that have identified agents such as cancer chemotherapeutic drugs, ionizing radiation, cigarette smoke, and air pollution as germ-cell mutagens. Research is urgently needed to establish the health consequences of parental exposures on subsequent generations.
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Affiliation(s)
| | | | - Scott S Auerbach
- National Institute of Environmental Health Sciences, United States
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Kristine L Witt
- National Institute of Environmental Health Sciences, United States
| | - Jack B Bishop
- National Institute of Environmental Health Sciences, United States
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19
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Demarini DM. Declaring the existence of human germ-cell mutagens. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2012; 53:166-172. [PMID: 22351488 DOI: 10.1002/em.21685] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 01/20/2011] [Accepted: 01/23/2011] [Indexed: 05/31/2023]
Abstract
After more than 80 years of searching for human germ-cell mutagens, I think that sufficient evidence already exists for a number of agents to be so considered, and definitive confirmation seems imminent due to the application of recently developed genomic techniques. In preparation for this, an assessment panel of internationally recognized experts in germ-cell biology and genomics is required to consider either the current evidence now, or impending genomic evidence later, to declare whether an agent is a human germ-cell mutagen. I propose that such a panel be organized under the aegis of the World Health Organization and constructed similarly to the working groups assembled by the International Agency for Research on Cancer for the evaluation of human carcinogens. Support from prominent national and international organizations would be important. Many regulatory agencies already have procedures in place for assessing potential human germ-cell mutagens, and the time is approaching when definitive genomic data in humans will obligate such evaluations. In my view, application of an IARC-type of assessment using available evidence leads to the conclusion that ionizing radiation, cancer chemotherapy, cigarette smoking, and air pollution are "Group 1" human germ-cell mutagens. Consideration of the potential adverse health effects to the unexposed offspring of an exposed parent will usher in an entirely new realm of environmental health assessment. I suggest that the long search for human germ-cell mutagens is about to end, and a demonstration of the much-anticipated linkage between heritable disease and environmental factors is poised to begin.
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Affiliation(s)
- David M Demarini
- Integrated Systems Toxicology Division, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA.
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20
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Shibata Y, Kumar P, Layer R, Willcox S, Gagan JR, Griffith JD, Dutta A. Extrachromosomal microDNAs and chromosomal microdeletions in normal tissues. Science 2012; 336:82-6. [PMID: 22403181 DOI: 10.1126/science.1213307] [Citation(s) in RCA: 183] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
We have identified tens of thousands of short extrachromosomal circular DNAs (microDNA) in mouse tissues as well as mouse and human cell lines. These microDNAs are 200 to 400 base pairs long, are derived from unique nonrepetitive sequence, and are enriched in the 5'-untranslated regions of genes, exons, and CpG islands. Chromosomal loci that are enriched sources of microDNA in the adult brain are somatically mosaic for microdeletions that appear to arise from the excision of microDNAs. Germline microdeletions identified by the "Thousand Genomes" project may also arise from the excision of microDNAs in the germline lineage. We have thus identified a previously unknown DNA entity in mammalian cells and provide evidence that their generation leaves behind deletions in different genomic loci.
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Affiliation(s)
- Yoshiyuki Shibata
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA
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21
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Crow YJ. Lupus: how much "complexity" is really (just) genetic heterogeneity? ACTA ACUST UNITED AC 2012; 63:3661-4. [PMID: 22127688 DOI: 10.1002/art.30603] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Yanick J Crow
- University of Manchester, Manchester Academic Health Science Centre, and Central Manchester Foundation Trust University Hospitals, Manchester, UK.
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22
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Liu P, Erez A, Nagamani SCS, Dhar SU, Kołodziejska KE, Dharmadhikari AV, Cooper ML, Wiszniewska J, Zhang F, Withers MA, Bacino CA, Campos-Acevedo LD, Delgado MR, Freedenberg D, Garnica A, Grebe TA, Hernández-Almaguer D, Immken L, Lalani SR, McLean SD, Northrup H, Scaglia F, Strathearn L, Trapane P, Kang SHL, Patel A, Cheung SW, Hastings PJ, Stankiewicz P, Lupski JR, Bi W. Chromosome catastrophes involve replication mechanisms generating complex genomic rearrangements. Cell 2011; 146:889-903. [PMID: 21925314 DOI: 10.1016/j.cell.2011.07.042] [Citation(s) in RCA: 331] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 06/06/2011] [Accepted: 07/25/2011] [Indexed: 10/25/2022]
Abstract
Complex genomic rearrangements (CGRs) consisting of two or more breakpoint junctions have been observed in genomic disorders. Recently, a chromosome catastrophe phenomenon termed chromothripsis, in which numerous genomic rearrangements are apparently acquired in one single catastrophic event, was described in multiple cancers. Here, we show that constitutionally acquired CGRs share similarities with cancer chromothripsis. In the 17 CGR cases investigated, we observed localization and multiple copy number changes including deletions, duplications, and/or triplications, as well as extensive translocations and inversions. Genomic rearrangements involved varied in size and complexities; in one case, array comparative genomic hybridization revealed 18 copy number changes. Breakpoint sequencing identified characteristic features, including small templated insertions at breakpoints and microhomology at breakpoint junctions, which have been attributed to replicative processes. The resemblance between CGR and chromothripsis suggests similar mechanistic underpinnings. Such chromosome catastrophic events appear to reflect basic DNA metabolism operative throughout an organism's life cycle.
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Affiliation(s)
- Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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23
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Lupski JR, Belmont JW, Boerwinkle E, Gibbs RA. Clan genomics and the complex architecture of human disease. Cell 2011; 147:32-43. [PMID: 21962505 PMCID: PMC3656718 DOI: 10.1016/j.cell.2011.09.008] [Citation(s) in RCA: 267] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 09/07/2011] [Accepted: 09/09/2011] [Indexed: 01/12/2023]
Abstract
Human diseases are caused by alleles that encompass the full range of variant types, from single-nucleotide changes to copy-number variants, and these variations span a broad frequency spectrum, from the very rare to the common. The picture emerging from analysis of whole-genome sequences, the 1000 Genomes Project pilot studies, and targeted genomic sequencing derived from very large sample sizes reveals an abundance of rare and private variants. One implication of this realization is that recent mutation may have a greater influence on disease susceptibility or protection than is conferred by variations that arose in distant ancestors.
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Affiliation(s)
- James R. Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
- Texas Children’s Hospital, University of Texas Health Science Center at Houston, Houston, TX 77030-1501, USA
| | - John W. Belmont
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Eric Boerwinkle
- Human Genetics Center, University of Texas Health Science Center at Houston, Houston, TX 77030-1501, USA
- The Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Richard A. Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- The Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
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Crow YJ. Sequencing revolution. Dev Med Child Neurol 2011; 53:673-4. [PMID: 21679360 DOI: 10.1111/j.1469-8749.2011.04016.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Boone PM, Wiszniewski W, Lupski JR. Genomic medicine and neurological disease. Hum Genet 2011; 130:103-21. [PMID: 21594611 PMCID: PMC3133694 DOI: 10.1007/s00439-011-1001-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 04/27/2011] [Indexed: 12/11/2022]
Abstract
"Genomic medicine" refers to the diagnosis, optimized management, and treatment of disease--as well as screening, counseling, and disease gene identification--in the context of information provided by an individual patient's personal genome. Genomic medicine, to some extent synonymous with "personalized medicine," has been made possible by recent advances in genome technologies. Genomic medicine represents a new approach to health care and disease management that attempts to optimize the care of a patient based upon information gleaned from his or her personal genome sequence. In this review, we describe recent progress in genomic medicine as it relates to neurological disease. Many neurological disorders either segregate as Mendelian phenotypes or occur sporadically in association with a new mutation in a single gene. Heritability also contributes to other neurological conditions that appear to exhibit more complex genetics. In addition to discussing current knowledge in this field, we offer suggestions for maximizing the utility of genomic information in clinical practice as the field of genomic medicine unfolds.
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Affiliation(s)
- Philip M Boone
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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Bonaglia MC, Giorda R, Beri S, De Agostini C, Novara F, Fichera M, Grillo L, Galesi O, Vetro A, Ciccone R, Bonati MT, Giglio S, Guerrini R, Osimani S, Marelli S, Zucca C, Grasso R, Borgatti R, Mani E, Motta C, Molteni M, Romano C, Greco D, Reitano S, Baroncini A, Lapi E, Cecconi A, Arrigo G, Patricelli MG, Pantaleoni C, D'Arrigo S, Riva D, Sciacca F, Dalla Bernardina B, Zoccante L, Darra F, Termine C, Maserati E, Bigoni S, Priolo E, Bottani A, Gimelli S, Bena F, Brusco A, di Gregorio E, Bagnasco I, Giussani U, Nitsch L, Politi P, Martinez-Frias ML, Martínez-Fernández ML, Martínez Guardia N, Bremer A, Anderlid BM, Zuffardi O. Molecular mechanisms generating and stabilizing terminal 22q13 deletions in 44 subjects with Phelan/McDermid syndrome. PLoS Genet 2011; 7:e1002173. [PMID: 21779178 PMCID: PMC3136441 DOI: 10.1371/journal.pgen.1002173] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 05/11/2011] [Indexed: 11/24/2022] Open
Abstract
In this study, we used deletions at 22q13, which represent a substantial source of human pathology (Phelan/McDermid syndrome), as a model for investigating the molecular mechanisms of terminal deletions that are currently poorly understood. We characterized at the molecular level the genomic rearrangement in 44 unrelated patients with 22q13 monosomy resulting from simple terminal deletions (72%), ring chromosomes (14%), and unbalanced translocations (7%). We also discovered interstitial deletions between 17-74 kb in 9% of the patients. Haploinsufficiency of the SHANK3 gene, confirmed in all rearrangements, is very likely the cause of the major neurological features associated with PMS. SHANK3 mutations can also result in language and/or social interaction disabilities. We determined the breakpoint junctions in 29 cases, providing a realistic snapshot of the variety of mechanisms driving non-recurrent deletion and repair at chromosome ends. De novo telomere synthesis and telomere capture are used to repair terminal deletions; non-homologous end-joining or microhomology-mediated break-induced replication is probably involved in ring 22 formation and translocations; non-homologous end-joining and fork stalling and template switching prevail in cases with interstitial 22q13.3. For the first time, we also demonstrated that distinct stabilizing events of the same terminal deletion can occur in different early embryonic cells, proving that terminal deletions can be repaired by multistep healing events and supporting the recent hypothesis that rare pathogenic germline rearrangements may have mitotic origin. Finally, the progressive clinical deterioration observed throughout the longitudinal medical history of three subjects over forty years supports the hypothesis of a role for SHANK3 haploinsufficiency in neurological deterioration, in addition to its involvement in the neurobehavioral phenotype of PMS.
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Bredenoord AL, Onland‐Moret NC, Van Delden JJ. Feedback of individual genetic results to research participants: in favor of a qualified disclosure policy. Hum Mutat 2011; 32:861-7. [DOI: 10.1002/humu.21518] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 04/19/2011] [Indexed: 01/08/2023]
Affiliation(s)
- Annelien L. Bredenoord
- Department of Medical Ethics, University Medical Center Utrecht, Division Julius Center, Utrecht, The Netherlands
| | - N. Charlotte Onland‐Moret
- Department of Epidemiology, University Medical Center Utrecht, Division Julius Center, Utrecht, The Netherlands
| | - Johannes J.M. Van Delden
- Department of Medical Ethics, University Medical Center Utrecht, Division Julius Center, Utrecht, The Netherlands
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Affiliation(s)
- Bertrand Jordan
- Marseille-Nice Génopole, case 901, Parc scientifique de Luminy, 13288 Marseille Cedex 9, France.
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