@article {1000, title = {A DNA repair disorder caused by de novo monoallelic DDB1 variants is associated with a neurodevelopmental syndrome.}, journal = {Am J Hum Genet}, volume = {108}, year = {2021}, month = {2021 04 01}, pages = {749-756}, abstract = {

The DNA damage-binding protein 1 (DDB1) is part of the CUL4-DDB1 ubiquitin E3 ligase complex (CRL4), which is essential for DNA repair, chromatin remodeling, DNA replication, and signal transduction. Loss-of-function variants in genes encoding the complex components CUL4 and PHIP have been reported to cause syndromic intellectual disability with hypotonia and obesity, but no phenotype has been reported in association with DDB1 variants. Here, we report eight unrelated individuals, identified through Matchmaker Exchange, with de novo monoallelic variants in DDB1, including one recurrent variant in four individuals. The affected individuals have a consistent phenotype of hypotonia, mild to moderate intellectual disability, and similar facies, including horizontal or slightly bowed eyebrows, deep-set eyes, full cheeks, a short nose, and large, fleshy and forward-facing earlobes, demonstrated in the composite face generated from the cohort. Digital anomalies, including brachydactyly and syndactyly, were common. Three older individuals have obesity. We show that cells derived from affected individuals have altered DDB1 function resulting in abnormal DNA damage signatures and histone methylation following UV-induced DNA damage. Overall, our study adds to the growing family of neurodevelopmental phenotypes mediated by disruption of the CRL4 ubiquitin ligase pathway and begins to delineate the phenotypic and molecular effects of DDB1 misregulation.

}, keywords = {Adolescent, Alleles, Child, Child, Preschool, DNA Repair, DNA-Binding Proteins, Female, Humans, Male, Mutation, Neurodevelopmental Disorders, Phenotype, Syndrome}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2021.03.007}, author = {White, Susan M and Bhoj, Elizabeth and Nellaker, Christoffer and Lachmeijer, Augusta M A and Marshall, Aren E and Boycott, Kym M and Li, Dong and Smith, Wendy and Hartley, Taila and McBride, Arran and Ernst, Michelle E and May, Alison S and Wieczorek, Dagmar and Abou Jamra, Rami and Koch-Hogrebe, Margarete and {\~O}unap, Katrin and Pajusalu, Sander and van Gassen, K L I and Sadedin, Simon and Ellingwood, Sara and Tan, Tiong Yang and Christodoulou, John and Barea, Jaime and Lockhart, Paul J and Nezarati, Marjan M and Kernohan, Kristin D} } @article {438, title = {ERCC4 variants identified in a cohort of patients with segmental progeroid syndromes.}, journal = {Hum Mutat}, volume = {39}, year = {2018}, month = {2018 02}, pages = {255-265}, abstract = {

Pathogenic variants in genes, which encode DNA repair and damage response proteins, result in a number of genomic instability syndromes with features of accelerated aging. ERCC4 (XPF) encodes a protein that forms a complex with ERCC1 and is required for the 5{\textquoteright} incision during nucleotide excision repair. ERCC4 is also FANCQ, illustrating a critical role in interstrand crosslink repair. Pathogenic variants in this gene cause xeroderma pigmentosum, XFE progeroid syndrome, Cockayne syndrome (CS), and Fanconi anemia. We performed massive parallel sequencing for 42 unsolved cases submitted to the International Registry of Werner Syndrome. Two cases, each carrying two novel heterozygous ERCC4 variants, were identified. The first case was a compound heterozygote for: c.2395C~>~T (p.Arg799Trp) and c.388+1164_792+795del (p.Gly130Aspfs*18). Further molecular and cellular studies indicated that the ERCC4 variants in this patient are responsible for a phenotype consistent with a variant of CS. The second case was heterozygous for two variants in cis: c.[1488A~>~T; c.2579C~>~A] (p.[Gln496His; Ala860Asp]). While the second case also had several phenotypic features of accelerated aging, we were unable to provide biological evidence supporting the pathogenic roles of the associated ERCC4 variants. Precise genetic causes and disease mechanism of the second case remains to be determined.

}, keywords = {Actins, Aged, Cockayne Syndrome, DNA Repair, DNA-Binding Proteins, Fanconi Anemia, Female, Genetic Predisposition to Disease, Humans, Lamin Type A, Male, Middle Aged, Pedigree, Xeroderma Pigmentosum}, issn = {1098-1004}, doi = {10.1002/humu.23367}, author = {Mori, Takayasu and Yousefzadeh, Matthew J and Faridounnia, Maryam and Chong, Jessica X and Hisama, Fuki M and Hudgins, Louanne and Mercado, Gabriela and Wade, Erin A and Barghouthy, Amira S and Lee, Lin and Martin, George M and Nickerson, Deborah A and Bamshad, Michael J and Niedernhofer, Laura J and Oshima, Junko} } @article {634, title = {Mutations in KEOPS-complex genes cause nephrotic syndrome with primary microcephaly.}, journal = {Nat Genet}, volume = {49}, year = {2017}, month = {2017 Oct}, pages = {1529-1538}, abstract = {

Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms.

}, keywords = {Animals, Apoptosis, Carrier Proteins, Cell Movement, CRISPR-Cas Systems, Cytoskeleton, DNA Repair, Endoplasmic Reticulum Stress, Gene Knockout Techniques, Hernia, Hiatal, Humans, Intracellular Signaling Peptides and Proteins, Metalloendopeptidases, Mice, Microcephaly, Models, Molecular, Multiprotein Complexes, Mutation, Nephrosis, Nephrotic Syndrome, Podocytes, Protein Conformation, Protein-Serine-Threonine Kinases, RNA Processing, Post-Transcriptional, RNA, Transfer, Telomere Homeostasis, Zebrafish, Zebrafish Proteins}, issn = {1546-1718}, doi = {10.1038/ng.3933}, author = {Braun, Daniela A and Rao, Jia and Mollet, Geraldine and Schapiro, David and Daugeron, Marie-Claire and Tan, Weizhen and Gribouval, Olivier and Boyer, Olivia and Revy, Patrick and Jobst-Schwan, Tilman and Schmidt, Johanna Magdalena and Lawson, Jennifer A and Schanze, Denny and Ashraf, Shazia and Ullmann, Jeremy F P and Hoogstraten, Charlotte A and Boddaert, Nathalie and Collinet, Bruno and Martin, Ga{\"e}lle and Liger, Dominique and Lovric, Svjetlana and Furlano, Monica and Guerrera, I Chiara and Sanchez-Ferras, Oraly and Hu, Jennifer F and Boschat, Anne-Claire and Sanquer, Sylvia and Menten, Bj{\"o}rn and Vergult, Sarah and De Rocker, Nina and Airik, Merlin and Hermle, Tobias and Shril, Shirlee and Widmeier, Eugen and Gee, Heon Yung and Choi, Won-Il and Sadowski, Carolin E and Pabst, Werner L and Warejko, Jillian K and Daga, Ankana and Basta, Tamara and Matejas, Verena and Scharmann, Karin and Kienast, Sandra D and Behnam, Babak and Beeson, Brendan and Begtrup, Amber and Bruce, Malcolm and Ch{\textquoteright}ng, Gaik-Siew and Lin, Shuan-Pei and Chang, Jui-Hsing and Chen, Chao-Huei and Cho, Megan T and Gaffney, Patrick M and Gipson, Patrick E and Hsu, Chyong-Hsin and Kari, Jameela A and Ke, Yu-Yuan and Kiraly-Borri, Cathy and Lai, Wai-Ming and Lemyre, Emmanuelle and Littlejohn, Rebecca Okashah and Masri, Amira and Moghtaderi, Mastaneh and Nakamura, Kazuyuki and Ozaltin, Fatih and Praet, Marleen and Prasad, Chitra and Prytula, Agnieszka and Roeder, Elizabeth R and Rump, Patrick and Schnur, Rhonda E and Shiihara, Takashi and Sinha, Manish D and Soliman, Neveen A and Soulami, Kenza and Sweetser, David A and Tsai, Wen-Hui and Tsai, Jeng-Daw and Topaloglu, Rezan and Vester, Udo and Viskochil, David H and Vatanavicharn, Nithiwat and Waxler, Jessica L and Wierenga, Klaas J and Wolf, Matthias T F and Wong, Sik-Nin and Leidel, Sebastian A and Truglio, Gessica and Dedon, Peter C and Poduri, Annapurna and Mane, Shrikant and Lifton, Richard P and Bouchard, Maxime and Kannu, Peter and Chitayat, David and Magen, Daniella and Callewaert, Bert and van Tilbeurgh, Herman and Zenker, Martin and Antignac, Corinne and Hildebrandt, Friedhelm} } @article {185, title = {Absence of heterozygosity due to template switching during replicative rearrangements.}, journal = {Am J Hum Genet}, volume = {96}, year = {2015}, month = {2015 Apr 02}, pages = {555-64}, abstract = {

We investigated complex genomic rearrangements (CGRs) consisting of triplication copy-number variants (CNVs) that were accompanied by extended regions of copy-number-neutral absence of heterozygosity (AOH) in subjects with multiple congenital abnormalities. Molecular analyses provided observational evidence that in humans, post-zygotically generated CGRs can lead to regional uniparental disomy (UPD) due to template switches between homologs versus sister chromatids by using microhomology to prime DNA replication-a prediction of the replicative repair model, MMBIR. Our findings suggest that replication-based mechanisms might underlie the formation of diverse types of genomic alterations (CGRs and AOH) implicated in constitutional disorders.

}, keywords = {Base Sequence, DNA Copy Number Variations, DNA Repair, DNA Replication, Gene Rearrangement, Humans, In Situ Hybridization, Fluorescence, Loss of Heterozygosity, Models, Genetic, Molecular Sequence Data, Netherlands, Polymerase Chain Reaction, Polymorphism, Single Nucleotide, Sequence Analysis, DNA, Uniparental Disomy}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.01.021}, author = {Carvalho, Claudia M B and Pfundt, Rolph and King, Daniel A and Lindsay, Sarah J and Zuccherato, Luciana W and Macville, Merryn V E and Liu, Pengfei and Johnson, Diana and Stankiewicz, Pawel and Brown, Chester W and Shaw, Chad A and Hurles, Matthew E and Ira, Grzegorz and Hastings, P J and Brunner, Han G and Lupski, James R} } @article {133, title = {DNA REPAIR. Mus81 and converging forks limit the mutagenicity of replication fork breakage.}, journal = {Science}, volume = {349}, year = {2015}, month = {2015 Aug 14}, pages = {742-7}, abstract = {

Most spontaneous DNA double-strand breaks (DSBs) result from replication-fork breakage. Break-induced replication (BIR), a genome rearrangement-prone repair mechanism that requires the Pol32/POLD3 subunit of eukaryotic DNA PolĪ“, was proposed to repair broken forks, but how genome destabilization is avoided was unknown. We show that broken fork repair initially uses error-prone Pol32-dependent synthesis, but that mutagenic synthesis is limited to within a few kilobases from the break by Mus81 endonuclease and a converging fork. Mus81 suppresses template switches between both homologous sequences and diverged human Alu repetitive elements, highlighting its importance for stability of highly repetitive genomes. We propose that lack of a timely converging fork or Mus81 may propel genome instability observed in cancer.

}, keywords = {Alu Elements, Base Sequence, DNA Breaks, Double-Stranded, DNA Repair, DNA Replication, DNA-Binding Proteins, DNA-Directed DNA Polymerase, Endonucleases, Genomic Instability, Humans, Molecular Sequence Data, Neoplasms, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins}, issn = {1095-9203}, doi = {10.1126/science.aaa8391}, author = {Mayle, Ryan and Campbell, Ian M and Beck, Christine R and Yu, Yang and Wilson, Marenda and Shaw, Chad A and Bjergbaek, Lotte and Lupski, James R and Ira, Grzegorz} } @article {288, title = {Replicative mechanisms for CNV formation are error prone.}, journal = {Nat Genet}, volume = {45}, year = {2013}, month = {2013 Nov}, pages = {1319-26}, abstract = {

We investigated 67 breakpoint junctions of gene copy number gains in 31 unrelated subjects. We observed a strikingly high frequency of small deletions and insertions (29\%) apparently originating from polymerase slippage events, in addition to frameshifts and point mutations in homonucleotide runs (13\%), at or flanking the breakpoint junctions of complex copy number variants. These single-nucleotide variants were generated concomitantly with the de novo complex genomic rearrangement (CGR) event. Our findings implicate low-fidelity, error-prone DNA polymerase activity in synthesis associated with DNA repair mechanisms as the cause of local increase in point mutation burden associated with human CGR.

}, keywords = {Base Sequence, DNA Breaks, DNA Copy Number Variations, DNA Repair, DNA Replication, Frameshift Mutation, Gene Rearrangement, Genetic Variation, Genotype, Humans, Sequence Analysis, DNA, Sequence Deletion}, issn = {1546-1718}, doi = {10.1038/ng.2768}, author = {Carvalho, Claudia M B and Pehlivan, Davut and Ramocki, Melissa B and Fang, Ping and Alleva, Benjamin and Franco, Luis M and Belmont, John W and Hastings, P J and Lupski, James R} }