@article {1008, title = {SPEN haploinsufficiency causes a neurodevelopmental disorder overlapping proximal 1p36 deletion syndrome with an episignature of X chromosomes in females.}, journal = {Am J Hum Genet}, volume = {108}, year = {2021}, month = {2021 03 04}, pages = {502-516}, abstract = {

Deletion 1p36 (del1p36) syndrome is the most common human disorder resulting from a terminal autosomal deletion. This condition is molecularly and clinically heterogeneous. Deletions involving two non-overlapping regions, known as the distal (telomeric) and proximal (centromeric) critical regions, are sufficient to cause the majority of the recurrent clinical features, although with different facial features and dysmorphisms. SPEN encodes a transcriptional repressor commonly deleted in proximal del1p36 syndrome and is located centromeric to the proximal 1p36 critical region. Here, we used clinical data from 34 individuals with truncating variants in SPEN to define a neurodevelopmental disorder presenting with features that overlap considerably with those of proximal del1p36 syndrome. The clinical profile of this disease includes developmental delay/intellectual disability, autism spectrum disorder, anxiety, aggressive behavior, attention deficit disorder, hypotonia, brain and spine anomalies, congenital heart defects, high/narrow palate, facial dysmorphisms, and obesity/increased BMI, especially in females. SPEN also emerges as a relevant gene for del1p36 syndrome by co-expression analyses. Finally, we show that haploinsufficiency of SPEN is associated with a distinctive DNA methylation episignature of the X chromosome in affected females, providing further evidence of a specific contribution of the protein to the epigenetic control of this chromosome, and a paradigm of an X chromosome-specific episignature that classifies syndromic traits. We conclude that SPEN is required for multiple developmental processes and SPEN haploinsufficiency is a major contributor to a disorder associated with deletions centromeric to the previously established 1p36 critical regions.

}, keywords = {Adolescent, Autism Spectrum Disorder, Child, Child, Preschool, Chromosome Deletion, Chromosome Disorders, Chromosomes, Human, Pair 1, Chromosomes, Human, X, DNA Methylation, DNA-Binding Proteins, Epigenesis, Genetic, Female, Haploinsufficiency, Humans, Intellectual Disability, Male, Neurodevelopmental Disorders, Phenotype, RNA-Binding Proteins, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2021.01.015}, author = {Radio, Francesca Clementina and Pang, Kaifang and Ciolfi, Andrea and Levy, Michael A and Hernandez-Garcia, Andres and Pedace, Lucia and Pantaleoni, Francesca and Liu, Zhandong and de Boer, Elke and Jackson, Adam and Bruselles, Alessandro and McConkey, Haley and Stellacci, Emilia and Lo Cicero, Stefania and Motta, Marialetizia and Carrozzo, Rosalba and Dentici, Maria Lisa and McWalter, Kirsty and Desai, Megha and Monaghan, Kristin G and Telegrafi, Aida and Philippe, Christophe and Vitobello, Antonio and Au, Margaret and Grand, Katheryn and Sanchez-Lara, Pedro A and Baez, Joanne and Lindstrom, Kristin and Kulch, Peggy and Sebastian, Jessica and Madan-Khetarpal, Suneeta and Roadhouse, Chelsea and MacKenzie, Jennifer J and Monteleone, Berrin and Saunders, Carol J and Jean Cuevas, July K and Cross, Laura and Zhou, Dihong and Hartley, Taila and Sawyer, Sarah L and Monteiro, Fabiola Paoli and Secches, Tania Vertemati and Kok, Fernando and Schultz-Rogers, Laura E and Macke, Erica L and Morava, Eva and Klee, Eric W and Kemppainen, Jennifer and Iascone, Maria and Selicorni, Angelo and Tenconi, Romano and Amor, David J and Pais, Lynn and Gallacher, Lyndon and Turnpenny, Peter D and Stals, Karen and Ellard, Sian and Cabet, Sara and Lesca, Gaetan and Pascal, Joset and Steindl, Katharina and Ravid, Sarit and Weiss, Karin and Castle, Alison M R and Carter, Melissa T and Kalsner, Louisa and de Vries, Bert B A and van Bon, Bregje W and Wevers, Marijke R and Pfundt, Rolph and Stegmann, Alexander P A and Kerr, Bronwyn and Kingston, Helen M and Chandler, Kate E and Sheehan, Willow and Elias, Abdallah F and Shinde, Deepali N and Towne, Meghan C and Robin, Nathaniel H and Goodloe, Dana and Vanderver, Adeline and Sherbini, Omar and Bluske, Krista and Hagelstrom, R Tanner and Zanus, Caterina and Faletra, Flavio and Musante, Luciana and Kurtz-Nelson, Evangeline C and Earl, Rachel K and Anderlid, Britt-Marie and Morin, Gilles and van Slegtenhorst, Marjon and Diderich, Karin E M and Brooks, Alice S and Gribnau, Joost and Boers, Ruben G and Finestra, Teresa Robert and Carter, Lauren B and Rauch, Anita and Gasparini, Paolo and Boycott, Kym M and Barakat, Tahsin Stefan and GrAHm, John M and Faivre, Laurence and Banka, Siddharth and Wang, Tianyun and Eichler, Evan E and Priolo, Manuela and Dallapiccola, Bruno and Vissers, Lisenka E L M and Sadikovic, Bekim and Scott, Daryl A and Holder, Jimmy Lloyd and Tartaglia, Marco} } @article {968, title = {Evaluating systematic reanalysis of clinical genomic data in rare disease from single center experience and literature review.}, journal = {Mol Genet Genomic Med}, volume = {8}, year = {2020}, month = {2020 11}, pages = {e1508}, abstract = {

BACKGROUND: Our primary aim was to evaluate the systematic reanalysis of singleton exome sequencing (ES) data for unsolved cases referred for any indication. A secondary objective was to undertake a literature review of studies examining the reanalysis of genomic data from unsolved cases.

METHODS: We examined data from 58 unsolved cases referred between June 2016 and March 2017. First reanalysis at 4-13~months after the initial report considered genes newly associated with disease since the original analysis; second reanalysis at 9-18~months considered all disease-associated genes. At 25-34~months we reviewed all cases and the strategies which solved them.

RESULTS: Reanalysis of existing ES data alone at two timepoints did not yield new diagnoses. Over the same timeframe, 10 new diagnoses were obtained (17\%) from additional strategies, such as microarray detection of copy number variation, repeat sequencing to improve coverage, and trio sequencing. Twenty-seven peer-reviewed articles were identified on the literature review, with a median new diagnosis rate via reanalysis of 15\% and median reanalysis timeframe of 22~months.

CONCLUSION: Our findings suggest that an interval of greater than 18~months from the original report may be optimal for reanalysis. We also recommend a multi-faceted strategy for cases remaining unsolved after singleton ES.

}, issn = {2324-9269}, doi = {10.1002/mgg3.1508}, author = {Tan, Natalie B and Stapleton, Rachel and Stark, Zornitza and Delatycki, Martin B and Yeung, Alison and Hunter, Matthew F and Amor, David J and Brown, Natasha J and Stutterd, Chloe A and McGillivray, George and Yap, Patrick and Regan, Matthew and Chong, Belinda and Fanjul Fernandez, Miriam and Marum, Justine and Phelan, Dean and Pais, Lynn S and White, Susan M and Lunke, Sebastian and Tan, Tiong Y} } @article {794, title = {Mutations disrupting neuritogenesis genes confer risk for cerebral palsy.}, journal = {Nat Genet}, volume = {52}, year = {2020}, month = {2020 10}, pages = {1046-1056}, abstract = {

In addition to commonly associated environmental factors, genomic factors may cause cerebral palsy. We performed whole-exome sequencing of 250 parent-offspring trios, and observed enrichment of damaging de novo mutations in cerebral palsy cases. Eight genes had multiple damaging de novo mutations; of these, two (TUBA1A and CTNNB1) met genome-wide significance. We identified two novel monogenic etiologies, FBXO31 and RHOB, and showed that the RHOB mutation enhances active-state Rho effector binding while the FBXO31 mutation diminishes cyclin D levels. Candidate cerebral palsy risk genes overlapped with neurodevelopmental disorder genes. Network analyses identified enrichment of Rho GTPase, extracellular matrix, focal adhesion and cytoskeleton pathways. Cerebral palsy risk genes in enriched pathways were shown to regulate neuromotor function in a Drosophila reverse genetics screen. We estimate that 14\% of cases could be attributed to an excess of damaging de novo or recessive variants. These findings provide evidence for genetically mediated dysregulation of early neuronal connectivity in cerebral palsy.

}, keywords = {Animals, beta Catenin, Cerebral Palsy, Cyclin D, Cytoskeleton, Drosophila, Exome, Extracellular Matrix, F-Box Proteins, Female, Focal Adhesions, Genetic Predisposition to Disease, Genome, Human, Humans, Male, Mutation, Neurites, rhoB GTP-Binding Protein, Risk Factors, Sequence Analysis, DNA, Signal Transduction, Tubulin, Tumor Suppressor Proteins, Whole Exome Sequencing}, issn = {1546-1718}, doi = {10.1038/s41588-020-0695-1}, author = {Jin, Sheng Chih and Lewis, Sara A and Bakhtiari, Somayeh and Zeng, Xue and Sierant, Michael C and Shetty, Sheetal and Nordlie, Sandra M and Elie, Aureliane and Corbett, Mark A and Norton, Bethany Y and van Eyk, Clare L and Haider, Shozeb and Guida, Brandon S and Magee, Helen and Liu, James and Pastore, Stephen and Vincent, John B and Brunstrom-Hernandez, Janice and Papavasileiou, Antigone and Fahey, Michael C and Berry, Jesia G and Harper, Kelly and Zhou, Chongchen and Zhang, Junhui and Li, Boyang and Zhao, Hongyu and Heim, Jennifer and Webber, Dani L and Frank, MAHlia S B and Xia, Lei and Xu, Yiran and Zhu, Dengna and Zhang, Bohao and Sheth, Amar H and Knight, James R and Castaldi, Christopher and Tikhonova, Irina R and L{\'o}pez-Gir{\'a}ldez, Francesc and Keren, Boris and Whalen, Sandra and Buratti, Julien and Doummar, Diane and Cho, Megan and Retterer, Kyle and Millan, Francisca and Wang, Yangong and Waugh, Jeff L and Rodan, Lance and Cohen, Julie S and Fatemi, Ali and Lin, Angela E and Phillips, John P and Feyma, Timothy and MacLennan, Suzanna C and Vaughan, Spencer and Crompton, Kylie E and Reid, Susan M and Reddihough, Dinah S and Shang, Qing and Gao, Chao and Novak, Iona and Badawi, Nadia and Wilson, Yana A and McIntyre, Sarah J and Mane, Shrikant M and Wang, Xiaoyang and Amor, David J and Zarnescu, Daniela C and Lu, Qiongshi and Xing, Qinghe and Zhu, Changlian and Bilguvar, Kaya and Padilla-Lopez, Sergio and Lifton, Richard P and Gecz, Jozef and MacLennan, Alastair H and Kruer, Michael C} } @article {725, title = {Bioinformatics-Based Identification of Expanded Repeats: A Non-reference Intronic Pentamer Expansion in RFC1 Causes CANVAS.}, journal = {Am J Hum Genet}, volume = {105}, year = {2019}, month = {2019 Jul 03}, pages = {151-165}, abstract = {

Genomic technologies such as next-generation sequencing (NGS) are revolutionizing molecular diagnostics and clinical medicine. However, these approaches have proven inefficient at identifying pathogenic repeat expansions. Here, we apply a collection of bioinformatics tools that can be utilized to identify either known or novel expanded repeat sequences in NGS data. We performed genetic studies of a cohort of 35 individuals from 22 families with a clinical diagnosis of cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS). Analysis of whole-genome sequence (WGS) data with five independent algorithms identified a recessively inherited intronic repeat expansion [(AAGGG)] in the gene encoding Replication Factor C1 (RFC1). This motif, not reported in the reference sequence, localized to an Alu element and replaced the reference (AAAAG) short tandem repeat. Genetic analyses confirmed the pathogenic expansion in 18 of 22 CANVAS-affected families and identified a core ancestral haplotype, estimated to have arisen in Europe more than twenty-five thousand years ago. WGS of the four RFC1-negative CANVAS-affected families identified plausible variants in three, with genomic re-diagnosis of SCA3, spastic ataxia of the Charlevoix-Saguenay type, and SCA45. This study identified the genetic basis of CANVAS and demonstrated that these improved bioinformatics tools increase the diagnostic utility of WGS to determine the genetic basis of a heterogeneous group of clinically overlapping neurogenetic disorders.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.05.016}, author = {Rafehi, Haloom and Szmulewicz, David J and Bennett, Mark F and Sobreira, Nara L M and Pope, Kate and Smith, Katherine R and Gillies, Greta and Diakumis, Peter and Dolzhenko, Egor and Eberle, Michael A and Barcina, Mar{\'\i}a Garc{\'\i}a and Breen, David P and Chancellor, Andrew M and Cremer, Phillip D and Delatycki, Martin B and Fogel, Brent L and Hackett, Anna and Halmagyi, G Michael and Kapetanovic, Solange and Lang, Anthony and Mossman, Stuart and Mu, Weiyi and Patrikios, Peter and Perlman, Susan L and Rosemergy, Ian and Storey, Elsdon and Watson, Shaun R D and Wilson, Michael A and Zee, David S and Valle, David and Amor, David J and Bahlo, Melanie and Lockhart, Paul J} } @article {709, title = {Clinical Spectrum and Functional Consequences Associated with Bi-Allelic Pathogenic Variants.}, journal = {J Clin Med}, volume = {8}, year = {2019}, month = {2019 Nov 19}, abstract = {

(PNPase-polynucleotide phosphorylase) is involved in multiple RNA processing functions in the mitochondria. Bi-allelic pathogenic variants cause heterogeneous clinical phenotypes affecting multiple organs without any established genotype-phenotype correlations. Defects in PNPase can cause variable combined respiratory chain complex defects. Recently, it has been suggested that PNPase can lead to activation of an innate immune response. To better understand the clinical and molecular spectrum of patients with bi-allelic variants, we captured detailed clinical and molecular phenotypes of all 17 patients reported in the literature, plus seven new patients, including a 78-year-old male with the longest reported survival. A functional follow-up of genomic sequencing by cDNA studies confirmed a splicing defect in a novel, apparently synonymous, variant. Patient fibroblasts showed an accumulation of mitochondrial unprocessed transcripts, while blood showed an increased interferon response. Our findings suggest that functional analyses of the RNA processing function of PNPase are more sensitive than testing downstream defects in oxidative phosphorylation (OXPHPOS) enzyme activities. This research extends our knowledge of the clinical and functional consequences of bi-allelic pathogenic variants that may guide management and further efforts into understanding the pathophysiological mechanisms for therapeutic development.

}, issn = {2077-0383}, doi = {10.3390/jcm8112020}, author = {Rius, Rocio and Van Bergen, Nicole J and Compton, Alison G and Riley, Lisa G and Kava, Maina P and Balasubramaniam, Shanti and Amor, David J and Fanjul-Fernandez, Miriam and Cowley, Mark J and Fahey, Michael C and Koenig, Mary K and Enns, Gregory M and Sadedin, Simon and Wilson, Meredith J and Tan, Tiong Y and Thorburn, David R and Christodoulou, John} } @article {732, title = {The Genetic Landscape of Diamond-Blackfan Anemia.}, journal = {Am J Hum Genet}, volume = {104}, year = {2019}, month = {2019 Feb 07}, pages = {356}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.12.011}, author = {Ulirsch, Jacob C and Verboon, Jeffrey M and Kazerounian, Shideh and Guo, Michael H and Yuan, Daniel and Ludwig, Leif S and Handsaker, Robert E and Abdulhay, Nour J and Fiorini, Claudia and Genovese, Giulio and Lim, Elaine T and Cheng, Aaron and Cummings, Beryl B and Chao, Katherine R and Beggs, Alan H and Genetti, Casie A and Sieff, Colin A and Newburger, Peter E and Niewiadomska, Edyta and Matysiak, Michal and Vlachos, Adrianna and Lipton, Jeffrey M and Atsidaftos, Eva and Glader, Bertil and Narla, Anupama and Gleizes, Pierre-Emmanuel and O{\textquoteright}Donohue, Marie-Fran{\c c}oise and Montel-Lehry, Nathalie and Amor, David J and McCarroll, Steven A and O{\textquoteright}Donnell-Luria, Anne H and Gupta, Namrata and Gabriel, Stacey B and MacArthur, Daniel G and Lander, Eric S and Lek, Monkol and Da Costa, Lydie and Nathan, David G and Korostelev, Andrei A and Do, Ron and Sankaran, Vijay G and Gazda, Hanna T} } @article {728, title = {Pathogenic Variants in GPC4 Cause Keipert Syndrome.}, journal = {Am J Hum Genet}, volume = {104}, year = {2019}, month = {2019 May 02}, pages = {914-924}, abstract = {

Glypicans are a family of cell-surface heparan sulfate proteoglycans that regulate growth-factor signaling during development and are thought to play a role in the regulation of morphogenesis. Whole-exome sequencing of the Australian family that defined Keipert syndrome (nasodigitoacoustic syndrome) identified a hemizygous truncating variant in the gene encoding glypican 4 (GPC4). This variant, located in the final exon of GPC4, results in premature termination of the protein 51 amino acid residues prior to the stop codon, and in concomitant loss of functionally important N-linked glycosylation (Asn514) and glycosylphosphatidylinositol (GPI) anchor (Ser529) sites. We subsequently identified seven affected males from five additional kindreds with novel and predicted pathogenic variants in GPC4. Segregation analysis and X-inactivation studies in carrier females provided supportive evidence that the GPC4 variants caused the condition. Furthermore, functional studies of recombinant protein suggested that the truncated proteins p.Gln506 and p.Glu496 were less stable than the wild type. Clinical features of Keipert syndrome included a prominent forehead, a flat midface, hypertelorism, a broad nose, downturned corners of mouth, and digital abnormalities, whereas cognitive impairment and deafness were variable features. Studies of Gpc4 knockout mice showed evidence of the two primary features of Keipert syndrome: craniofacial abnormalities and digital abnormalities. Phylogenetic analysis demonstrated that GPC4 is most closely related to GPC6, which is associated with a bone dysplasia that has a phenotypic overlap with Keipert syndrome. Overall, we have shown that pathogenic variants in GPC4 cause a loss of function that results in Keipert syndrome, making GPC4 the third human glypican to be linked to a genetic syndrome.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2019.02.026}, author = {Amor, David J and Stephenson, Sarah E M and Mustapha, Mirna and Mensah, Martin A and Ockeloen, Charlotte W and Lee, Wei Shern and Tankard, Rick M and Phelan, Dean G and Shinawi, Marwan and de Brouwer, Arjan P M and Pfundt, Rolph and Dowling, Cari and Toler, Tomi L and Sutton, V Reid and Agolini, Emanuele and Rinelli, Martina and Capolino, Rossella and Martinelli, Diego and Zampino, Giuseppe and Dumi{\'c}, Miroslav and Reardon, William and Shaw-Smith, Charles and Leventer, Richard J and Delatycki, Martin B and Kleefstra, Tjitske and Mundlos, Stefan and Mortier, Geert and Bahlo, Melanie and Allen, Nicola J and Lockhart, Paul J} } @article {578, title = {The Genetic Landscape of Diamond-Blackfan Anemia.}, journal = {Am J Hum Genet}, volume = {103}, year = {2018}, month = {2018 12 06}, pages = {930-947}, abstract = {

Diamond-Blackfan anemia (DBA) is a rare bone marrow failure disorder that affects 7 out of 1,000,000 live births and has been associated with mutations in components of the ribosome. In order to characterize the genetic landscape of this heterogeneous disorder, we recruited a cohort of 472 individuals with a clinical diagnosis of DBA and performed whole-exome sequencing (WES). We identified relevant rare and predicted damaging mutations for 78\% of individuals. The majority of mutations were singletons, absent from population databases, predicted to cause loss of function, and located in 1 of 19 previously reported ribosomal protein (RP)-encoding genes. Using exon coverage estimates, we identified and validated 31 deletions in RP genes. We also observed an enrichment for extended splice site mutations and validated their diverse effects using RNA sequencing in cell lines obtained from individuals with DBA. Leveraging the size of our cohort, we observed robust genotype-phenotype associations with congenital abnormalities and treatment outcomes. We further identified rare mutations in seven previously unreported RP genes that may cause DBA, as well as several distinct disorders that appear to phenocopy DBA, including nine individuals with biallelic CECR1 mutations that result in deficiency of ADA2. However, no new genes were identified at exome-wide significance, suggesting that there are no unidentified genes containing mutations readily identified by WES that explain >5\% of DBA-affected case subjects. Overall, this report should inform not only clinical practice for DBA-affected individuals, but also the design and analysis of rare variant studies for heterogeneous Mendelian disorders.

}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.10.027}, author = {Ulirsch, Jacob C and Verboon, Jeffrey M and Kazerounian, Shideh and Guo, Michael H and Yuan, Daniel and Ludwig, Leif S and Handsaker, Robert E and Abdulhay, Nour J and Fiorini, Claudia and Genovese, Giulio and Lim, Elaine T and Cheng, Aaron and Cummings, Beryl B and Chao, Katherine R and Beggs, Alan H and Genetti, Casie A and Sieff, Colin A and Newburger, Peter E and Niewiadomska, Edyta and Matysiak, Michal and Vlachos, Adrianna and Lipton, Jeffrey M and Atsidaftos, Eva and Glader, Bertil and Narla, Anupama and Gleizes, Pierre-Emmanuel and O{\textquoteright}Donohue, Marie-Fran{\c c}oise and Montel-Lehry, Nathalie and Amor, David J and McCarroll, Steven A and O{\textquoteright}Donnell-Luria, Anne H and Gupta, Namrata and Gabriel, Stacey B and MacArthur, Daniel G and Lander, Eric S and Lek, Monkol and Da Costa, Lydie and Nathan, David G and Korostelev, Andrei A and Do, Ron and Sankaran, Vijay G and Gazda, Hanna T} } @article {74, title = {Mosaic Activating Mutations in FGFR1 Cause Encephalocraniocutaneous Lipomatosis.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 Mar 03}, pages = {579-587}, abstract = {

Encephalocraniocutaneous lipomatosis (ECCL) is a sporadic condition characterized by ocular, cutaneous, and central nervous system anomalies. Key clinical features include a well-demarcated hairless fatty nevus on the scalp, benign ocular tumors, and central nervous system lipomas. Seizures, spasticity, and intellectual disability can be present, although affected individuals without seizures and with normal intellect have also been reported. Given the patchy and asymmetric nature of the malformations, ECCL has been hypothesized to be due to a post-zygotic, mosaic mutation. Despite phenotypic overlap with several other disorders associated with mutations in the RAS-MAPK and PI3K-AKT pathways, the molecular etiology of ECCL remains unknown. Using exome sequencing of DNA from multiple affected tissues from five unrelated individuals with ECCL, we identified two mosaic mutations, c.1638C>A (p.Asn546Lys) and c.1966A>G (p.Lys656Glu) within the tyrosine kinase domain of FGFR1, in two affected individuals each. These two residues are the most commonly mutated residues in FGFR1 in human cancers and are associated primarily with CNS tumors. Targeted resequencing of FGFR1 in multiple tissues from an independent cohort of individuals with ECCL identified one additional individual with a c.1638C>A (p.Asn546Lys) mutation in FGFR1. Functional studies of ECCL fibroblast cell lines show increased levels of phosphorylated FGFRs and phosphorylated FRS2, a direct substrate of FGFR1, as well as constitutive activation of RAS-MAPK signaling. In addition to identifying the molecular etiology of ECCL, our results support the emerging overlap between mosaic developmental disorders and tumorigenesis.

}, keywords = {Adolescent, Cell Line, Tumor, Central Nervous System Neoplasms, Child, Preschool, Exome, Eye, Eye Diseases, Female, Humans, Infant, Lipomatosis, Male, Mutation, Mutation, Missense, Neurocutaneous Syndromes, Phosphatidylinositol 3-Kinases, Proto-Oncogene Proteins c-akt, Receptor, Fibroblast Growth Factor, Type 1, Seizures, Sequence Analysis, DNA}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.02.006}, author = {Bennett, James T and Tan, Tiong Yang and Alcantara, Diana and T{\'e}trault, Martine and Timms, Andrew E and Jensen, Dana and Collins, Sarah and Nowaczyk, Malgorzata J M and Lindhurst, Marjorie J and Christensen, Katherine M and Braddock, Stephen R and Brandling-Bennett, Heather and Hennekam, Raoul C M and Chung, Brian and Lehman, Anna and Su, John and Ng, SuYuen and Amor, David J and Majewski, Jacek and Biesecker, Les G and Boycott, Kym M and Dobyns, William B and O{\textquoteright}Driscoll, Mark and Moog, Ute and McDonell, Laura M} } @article {258, title = {Expanding the phenotypic spectrum of ARID1B-mediated disorders and identification of altered cell-cycle dynamics due to ARID1B haploinsufficiency.}, journal = {Orphanet J Rare Dis}, volume = {9}, year = {2014}, month = {2014 Mar 27}, pages = {43}, abstract = {

BACKGROUND: Mutations in genes encoding components of the Brahma-associated factor (BAF) chromatin remodeling complex have recently been shown to contribute to multiple syndromes characterised by developmental delay and intellectual disability. ARID1B mutations have been identified as the predominant cause of Coffin-Siris syndrome and have also been shown to be a frequent cause of nonsyndromic intellectual disability. Here, we investigate the molecular basis of a patient with an overlapping but distinctive phenotype of intellectual disability, plantar fat pads and facial dysmorphism.

METHODS/RESULTS: High density microarray analysis of the patient demonstrated a heterozygous deletion at 6q25.3, which resulted in the loss of four genes including AT Rich Interactive Domain 1B (ARID1B). Subsequent quantitative real-time PCR analysis revealed ARID1B haploinsufficiency in the patient. Analysis of both patient-derived and ARID1B knockdown fibroblasts after serum starvation demonstrated delayed cell cycle re-entry associated with reduced cell number in the S1 phase. Based on the patient{\textquoteright}s distinctive phenotype, we ascertained four additional patients and identified heterozygous de novo ARID1B frameshift or nonsense mutations in all of them.

CONCLUSIONS: This study broadens the spectrum of ARID1B associated phenotypes by describing a distinctive phenotype including plantar fat pads but lacking the hypertrichosis or fifth nail hypoplasia associated with Coffin-Siris syndrome. We present the first direct evidence in patient-derived cells that alterations in cell cycle contribute to the underlying pathogenesis of syndromes associated with ARID1B haploinsufficiency.

}, keywords = {Abnormalities, Multiple, Cell Cycle, Chromatin Assembly and Disassembly, DNA-Binding Proteins, Face, Female, Hand Deformities, Congenital, Haploinsufficiency, Humans, Intellectual Disability, Male, Micrognathism, Neck, Transcription Factors}, issn = {1750-1172}, doi = {10.1186/1750-1172-9-43}, author = {Sim, Joe C H and White, Susan M and Fitzpatrick, Elizabeth and Wilson, Gabrielle R and Gillies, Greta and Pope, Kate and Mountford, Hayley S and Torring, Pernille M and McKee, Shane and Vulto-van Silfhout, Anneke T and Jhangiani, Shalini N and Muzny, Donna M and Leventer, Richard J and Delatycki, Martin B and Amor, David J and Lockhart, Paul J} } @article {273, title = {Loss-of-function HDAC8 mutations cause a phenotypic spectrum of Cornelia de Lange syndrome-like features, ocular hypertelorism, large fontanelle and X-linked inheritance.}, journal = {Hum Mol Genet}, volume = {23}, year = {2014}, month = {2014 Jun 01}, pages = {2888-900}, abstract = {

Cornelia de Lange syndrome (CdLS) is a multisystem genetic disorder with distinct facies, growth failure, intellectual disability, distal limb anomalies, gastrointestinal and neurological disease. Mutations in NIPBL, encoding a cohesin regulatory protein, account for >80\% of cases with typical facies. Mutations in the core cohesin complex proteins, encoded by the SMC1A, SMC3 and RAD21 genes, together account for \~{}5\% of subjects, often with atypical CdLS features. Recently, we identified mutations in the X-linked gene HDAC8 as the cause of a small number of CdLS cases. Here, we report a cohort of 38 individuals with an emerging spectrum of features caused by HDAC8 mutations. For several individuals, the diagnosis of CdLS was not considered prior to genomic testing. Most mutations identified are missense and de novo. Many cases are heterozygous females, each with marked skewing of X-inactivation in peripheral blood DNA. We also identified eight hemizygous males who are more severely affected. The craniofacial appearance caused by HDAC8 mutations overlaps that of typical CdLS but often displays delayed anterior fontanelle closure, ocular hypertelorism, hooding of the eyelids, a broader nose and dental anomalies, which may be useful discriminating features. HDAC8 encodes the lysine deacetylase for the cohesin subunit SMC3 and analysis of the functional consequences of the missense mutations indicates that all cause a loss of enzymatic function. These data demonstrate that loss-of-function mutations in HDAC8 cause a range of overlapping human developmental phenotypes, including a phenotypically distinct subgroup of CdLS.

}, keywords = {Amino Acid Sequence, Child, Child, Preschool, Cohort Studies, Cranial Fontanelles, De Lange Syndrome, Eye Abnormalities, Female, Genes, X-Linked, Histone Deacetylases, Humans, Hypertelorism, Infant, Male, Molecular Sequence Data, Mutation, Missense, Phenotype, Repressor Proteins, Sequence Alignment}, issn = {1460-2083}, doi = {10.1093/hmg/ddu002}, author = {Kaiser, Frank J and Ansari, Morad and Braunholz, Diana and Concepci{\'o}n Gil-Rodr{\'\i}guez, Mar{\'\i}a and Decroos, Christophe and Wilde, Jonathan J and Fincher, Christopher T and Kaur, Maninder and Bando, Masashige and Amor, David J and Atwal, Paldeep S and Bahlo, Melanie and Bowman, Christine M and Bradley, Jacquelyn J and Brunner, Han G and Clark, Dinah and Del Campo, Miguel and Di Donato, Nataliya and Diakumis, Peter and Dubbs, Holly and Dyment, David A and Eckhold, Juliane and Ernst, Sarah and Ferreira, Jose C and Francey, Lauren J and Gehlken, Ulrike and Guill{\'e}n-Navarro, Encarna and Gyftodimou, Yolanda and Hall, Bryan D and Hennekam, Raoul and Hudgins, Louanne and Hullings, Melanie and Hunter, Jennifer M and Yntema, Helger and Innes, A Micheil and Kline, Antonie D and Krumina, Zita and Lee, Hane and Leppig, Kathleen and Lynch, Sally Ann and Mallozzi, Mark B and Mannini, Linda and McKee, Shane and Mehta, Sarju G and Micule, Ieva and Mohammed, Shehla and Moran, Ellen and Mortier, Geert R and Moser, Joe-Ann S and Noon, Sarah E and Nozaki, Naohito and Nunes, Luis and Pappas, John G and Penney, Lynette S and P{\'e}rez-Ayt{\'e}s, Antonio and Petersen, Michael B and Puisac, Beatriz and Revencu, Nicole and Roeder, Elizabeth and Saitta, Sulagna and Scheuerle, Angela E and Schindeler, Karen L and Siu, Victoria M and Stark, Zornitza and Strom, Samuel P and Thiese, Heidi and Vater, Inga and Willems, Patrick and Williamson, Kathleen and Wilson, Louise C and Hakonarson, Hakon and Quintero-Rivera, Fabiola and Wierzba, Jolanta and Musio, Antonio and Gillessen-Kaesbach, Gabriele and Ramos, Feliciano J and Jackson, Laird G and Shirahige, Katsuhiko and Pi{\'e}, Juan and Christianson, David W and Krantz, Ian D and FitzPatrick, David R and Deardorff, Matthew A} }