@article {998, title = {CSNK2B: A broad spectrum of neurodevelopmental disability and epilepsy severity.}, journal = {Epilepsia}, year = {2021}, month = {2021 May 26}, abstract = {

CSNK2B has recently been implicated as a disease gene for neurodevelopmental disability (NDD) and epilepsy. Information about developmental outcomes has been limited by the young age and short follow-up for many of the previously reported cases, and further delineation of the spectrum of associated phenotypes is needed. We present 25 new patients with variants in CSNK2B and refine the associated NDD and epilepsy phenotypes. CSNK2B variants were identified by research or clinical exome sequencing, and investigators from different centers were connected via GeneMatcher. Most individuals had developmental delay and generalized epilepsy with onset in the first 2 years. However, we found a broad spectrum of phenotypic severity, ranging from early normal development with pharmacoresponsive seizures to profound intellectual disability with intractable epilepsy and recurrent refractory status epilepticus. These findings suggest that CSNK2B should be considered in the diagnostic evaluation of patients with a broad range of NDD with treatable or intractable seizures.

}, issn = {1528-1167}, doi = {10.1111/epi.16931}, author = {Ernst, Michelle E and Baugh, Evan H and Thomas, Amanda and Bier, Louise and Lippa, Natalie and Stong, Nicholas and Mulhern, Maureen S and Kushary, Sulagna and Akman, Cigdem I and Heinzen, Erin L and Yeh, Raymond and Bi, Weimin and Hanchard, Neil A and Burrage, Lindsay C and Leduc, Magalie S and Chong, Josephine S C and Bend, Renee and Lyons, Michael J and Lee, Jennifer A and Suwannarat, Pim and Brilstra, Eva and Simon, Marleen and Koopmans, Marije and van Binsbergen, Ellen and Groepper, Daniel and Fleischer, Julie and Nava, Caroline and Keren, Boris and Mignot, Cyril and Mathieu, Sophie and Mancini, Grazia M S and Madan-Khetarpal, Suneeta and Infante, Elena M and Bluvstein, Judith and Seeley, Andrea and Bachman, Kristine and Klee, Eric W and Schultz-Rogers, Laura E and Hasadsri, Linda and Barnett, Sarah and Ellingson, Marissa S and Ferber, Matthew J and Narayanan, Vinodh and Ramsey, Keri and Rauch, Anita and Joset, Pascal and Steindl, Katharina and Sheehan, Theodore and Poduri, Annapurna and Vasquez, Alejandra and Ruivenkamp, Claudia and White, Susan M and Pais, Lynn and Monaghan, Kristin G and Goldstein, David B and Sands, Tristan T and Aggarwal, Vimla} } @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 {891, title = {Germline mutation in : a heterogeneous, multi-systemic developmental disorder characterized by transcriptional dysregulation.}, journal = {HGG Adv}, volume = {2}, year = {2021}, month = {2021 Jan 14}, abstract = {

germline variation in was recently reported to associate with a neurodevelopmental disorder. We report twelve individuals harboring putatively pathogenic or inherited variants in , detail their phenotypes, and map all known variants to the domain structure of and crystal structure of RNA polymerase II. Affected individuals were ascertained from a local data lake, pediatric genetics clinic, and an online community of families of affected individuals. These include six affected by missense variants (including one previously reported individual), four clinical laboratory samples affected by missense variation with unknown inheritance-with yeast functional assays further supporting altered function-one affected by a in-frame deletion, and one affected by a C-terminal frameshift variant inherited from a largely asymptomatic mother. Recurrently observed phenotypes include ataxia, joint hypermobility, short stature, skin abnormalities, congenital cardiac abnormalities, immune system abnormalities, hip dysplasia, and short Achilles tendons. We report a significantly higher occurrence of epilepsy (8/12, 66.7\%) than previously reported (3/15, 20\%) (p value = 0.014196; chi-square test) and a lower occurrence of hypotonia (8/12, 66.7\%) than previously reported (14/15, 93.3\%) (p value = 0.076309). -related developmental disorders likely represent a spectrum of related, multi-systemic developmental disorders, driven by distinct mechanisms, converging at a single locus.

}, issn = {2666-2477}, doi = {10.1016/j.xhgg.2020.100014}, author = {Hansen, Adam W and Arora, Payal and Khayat, Michael M and Smith, Leah J and Lewis, Andrea M and Rossetti, Linda Z and Jayaseelan, Joy and Cristian, Ingrid and Haynes, Devon and DiTroia, Stephanie and Meeks, Naomi and Delgado, Mauricio R and Rosenfeld, Jill A and Pais, Lynn and White, Susan M and Meng, Qingchang and Pehlivan, Davut and Liu, Pengfei and Gingras, Marie-Claude and Wangler, Michael F and Muzny, Donna M and Lupski, James R and Kaplan, Craig D and Gibbs, Richard A} } @article {957, title = {Multiomic analysis elucidates Complex I deficiency caused by a deep intronic variant in NDUFB10.}, journal = {Hum Mutat}, volume = {42}, year = {2021}, month = {2021 Jan}, pages = {19-24}, abstract = {

The diagnosis of Mendelian disorders following uninformative exome and genome sequencing remains a challenging and often unmet need. Following uninformative exome and genome sequencing of a family quartet including two siblings with suspected mitochondrial disorder, RNA sequencing (RNAseq) was pursued in one sibling. Long-read amplicon sequencing was used to determine and quantify transcript structure. Immunoblotting studies and quantitative proteomics were performed to demonstrate functional impact. Differential expression analysis of RNAseq data identified significantly decreased expression of the mitochondrial OXPHOS Complex I subunit NDUFB10 associated with a cryptic exon in intron 1 of NDUFB10, that included an in-frame stop codon. The cryptic exon contained a rare intronic variant that was homozygous in both affected siblings. Immunoblot and quantitative proteomic analysis of fibroblasts revealed decreased abundance of Complex I subunits, providing evidence of isolated Complex I deficiency. Through multiomic analysis we present data implicating a deep intronic variant in NDUFB10 as the cause of mitochondrial disease in two individuals, providing further support of the gene-disease association. This study highlights the importance of transcriptomic and proteomic analyses as complementary diagnostic tools in patients undergoing genome-wide diagnostic evaluation.

}, issn = {1098-1004}, doi = {10.1002/humu.24135}, author = {Helman, Guy and Compton, Alison G and Hock, Daniella H and Walkiewicz, Marzena and Brett, Gemma R and Pais, Lynn and Tan, Tiong Y and De Paoli-Iseppi, Ricardo and Clark, Michael B and Christodoulou, John and White, Susan M and Thorburn, David R and Stroud, David A and Stark, Zornitza and Simons, Cas} } @article {1012, title = {Pathogenic variants in , a chromatin remodeler, cause a range of syndromic neurodevelopmental features.}, journal = {Sci Adv}, volume = {7}, year = {2021}, month = {2021 May}, abstract = {

Intellectual disability encompasses a wide spectrum of neurodevelopmental disorders, with many linked genetic loci. However, the underlying molecular mechanism for more than 50\% of the patients remains elusive. We describe pathogenic variants in , encoding the ATPase motor of the ISWI chromatin remodeler, as a cause of a previously unidentified neurodevelopmental disorder, identifying 12 individuals with de novo or dominantly segregating rare heterozygous variants. Accompanying phenotypes include mild developmental delay, frequent postnatal short stature and microcephaly, and recurrent dysmorphic features. Loss of function of the SMARCA5 ortholog led to smaller body size, reduced sensory dendrite complexity, and tiling defects in larvae. In adult flies, Iswi neural knockdown caused decreased brain size, aberrant mushroom body morphology, and abnormal locomotor function. loss of function was rescued by wild-type but not mutant SMARCA5. Our results demonstrate that pathogenic variants cause a neurodevelopmental syndrome with mild facial dysmorphia.

}, issn = {2375-2548}, doi = {10.1126/sciadv.abf2066}, author = {Li, Dong and Wang, Qin and Gong, Naihua N and Kurolap, Alina and Feldman, Hagit Baris and Boy, Nikolas and Brugger, Melanie and Grand, Katheryn and McWalter, Kirsty and Guillen Sacoto, Maria J and Wakeling, Emma and Hurst, Jane and March, Michael E and Bhoj, Elizabeth J and Nowaczyk, Ma{\l}gorzata J M and Gonzaga-Jauregui, Claudia and Mathew, Mariam and Dava-Wala, Ashita and Siemon, Amy and Bartholomew, Dennis and Huang, Yue and Lee, Hane and Martinez-Agosto, Julian A and Schwaibold, Eva M C and Brunet, Theresa and Choukair, Daniela and Pais, Lynn S and White, Susan M and Christodoulou, John and Brown, Dana and Lindstrom, Kristin and Grebe, Theresa and Tiosano, Dov and Kayser, Matthew S and Tan, Tiong Yang and Deardorff, Matthew A and Song, Yuanquan and Hakonarson, Hakon} } @article {779, title = {Bi-allelic ADARB1 Variants Associated with Microcephaly, Intellectual Disability, and Seizures.}, journal = {Am J Hum Genet}, volume = {106}, year = {2020}, month = {2020 04 02}, pages = {467-483}, abstract = {

The RNA editing enzyme ADAR2 is essential for the recoding of brain transcripts. Impaired ADAR2 editing leads to early-onset epilepsy and premature death in a mouse model. Here, we report bi-allelic variants in ADARB1, the gene encoding ADAR2, in four unrelated individuals with microcephaly, intellectual disability, and epilepsy. In one individual, a homozygous variant in one of the double-stranded RNA-binding domains (dsRBDs) was identified. In the others, variants were situated in or around the deaminase domain. To evaluate the effects of these variants on ADAR2 enzymatic activity, we performed in~vitro assays with recombinant proteins in HEK293T cells and ex~vivo assays with fibroblasts derived from one of the individuals. We demonstrate that these ADAR2 variants lead to reduced editing activity on a known ADAR2 substrate. We also demonstrate that one variant leads to changes in splicing of ADARB1 transcript isoforms. These findings reinforce the importance of RNA editing in brain development and introduce ADARB1 as a genetic etiology in individuals with intellectual disability, microcephaly, and epilepsy.

}, keywords = {Adenosine Deaminase, Alleles, Alternative Splicing, Child, Child, Preschool, Genetic Predisposition to Disease, Genetic Variation, HEK293 Cells, Humans, Intellectual Disability, Male, Microcephaly, RNA Splicing, RNA-Binding Proteins, Seizures}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2020.02.015}, author = {Tan, Tiong Yang and Sedm{\'\i}k, Ji{\v r}{\'\i} and Fitzgerald, Mark P and Halevy, Rivka Sukenik and Keegan, Liam P and Helbig, Ingo and Basel-Salmon, Lina and Cohen, Lior and Straussberg, Rachel and Chung, Wendy K and Helal, Mayada and Maroofian, Reza and Houlden, Henry and Juusola, Jane and Sadedin, Simon and Pais, Lynn and Howell, Katherine B and White, Susan M and Christodoulou, John and O{\textquoteright}Connell, Mary A} } @article {962, title = {Bi-allelic Variations of SMO in Humans Cause a Broad Spectrum of Developmental Anomalies Due to Abnormal Hedgehog Signaling.}, journal = {Am J Hum Genet}, volume = {106}, year = {2020}, month = {2020 06 04}, pages = {779-792}, abstract = {

The evolutionarily conserved hedgehog (Hh) pathway is essential for organogenesis and plays critical roles in postnatal tissue maintenance and renewal. A unique feature of the vertebrate Hh pathway is that signal transduction requires the primary cilium (PC) where major pathway components are dynamically enriched. These factors include smoothened (SMO) and patched, which constitute the core reception system for sonic hedgehog (SHH) as well as GLI transcription factors, the key mediators of the pathway. Here, we report bi-allelic loss-of-function variations in SMO in seven individuals from five independent families; these variations cause a wide phenotypic spectrum of developmental anomalies affecting the brain (hypothalamic hamartoma and microcephaly), heart (atrioventricular septal defect), skeleton (postaxial polydactyly, narrow chest, and shortening of long bones), and enteric nervous system (aganglionosis). Cells derived from affected individuals showed normal ciliogenesis but severely altered Hh-signal transduction as a result of either altered PC trafficking or abnormal activation of the pathway downstream of SMO. In addition, Hh-independent GLI2 accumulation at the PC tip in cells from the affected individuals suggests a potential function of SMO in regulating basal ciliary trafficking of GLI2 when the pathway is off. Thus, loss of SMO function results in abnormal PC dynamics of key components of the Hh signaling pathway and leads to a large continuum of malformations in humans.

}, keywords = {Alleles, Base Sequence, Child, Child, Preschool, Cilia, Developmental Disabilities, Female, Hedgehog Proteins, Humans, Infant, Male, Models, Molecular, Neoplasms, Nerve Tissue Proteins, Nuclear Proteins, Pedigree, Signal Transduction, Smoothened Receptor, Zinc Finger Protein Gli2, Zinc Finger Protein Gli3}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2020.04.010}, author = {Le, Thuy-Linh and Sribudiani, Yunia and Dong, Xiaomin and Huber, Celine and Kois, Chelsea and Baujat, Genevi{\`e}ve and Gordon, Christopher T and Mayne, Valerie and Galmiche, Louise and Serre, Val{\'e}rie and Goudin, Nicolas and Zarhrate, Mohammed and Bole-Feysot, Christine and Masson, Cecile and Nitschk{\'e}, Patrick and Verheijen, Frans W and Pais, Lynn and Pelet, Anna and Sadedin, Simon and Pugh, John A and Shur, Natasha and White, Susan M and El Chehadeh, Salima and Christodoulou, John and Cormier-Daire, Val{\'e}rie and Hofstra, R M W and Lyonnet, Stanislas and Tan, Tiong Yang and Atti{\'e}-Bitach, Tania and Kerstjens-Frederikse, Wilhelmina S and Amiel, Jeanne and Thomas, Sophie} } @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 {913, title = {Missense variant contribution to USP9X-female syndrome.}, journal = {NPJ Genom Med}, volume = {5}, year = {2020}, month = {2020 Dec 09}, pages = {53}, abstract = {

USP9X is an X-chromosome gene that escapes X-inactivation. Loss or compromised function of USP9X leads to neurodevelopmental disorders in males and females. While males are impacted primarily by hemizygous partial loss-of-function missense variants, in females de novo heterozygous complete loss-of-function mutations predominate, and give rise to the clinically recognisable USP9X-female syndrome. Here we provide evidence of the contribution of USP9X missense and small in-frame deletion variants in USP9X-female syndrome also. We scrutinise the pathogenicity of eleven such variants, ten of which were novel. Combined application of variant prediction algorithms, protein structure modelling, and assessment under clinically relevant guidelines universally support their pathogenicity. The core phenotype of this cohort overlapped with previous descriptions of USP9X-female syndrome, but exposed heightened variability. Aggregate phenotypic information of 35 currently known females with predicted pathogenic variation in USP9X reaffirms the clinically recognisable USP9X-female syndrome, and highlights major differences when compared to USP9X-male associated neurodevelopmental disorders.

}, issn = {2056-7944}, doi = {10.1038/s41525-020-00162-9}, author = {Jolly, Lachlan A and Parnell, Euan and Gardner, Alison E and Corbett, Mark A and P{\'e}rez-Jurado, Luis A and Shaw, Marie and Lesca, Gaetan and Keegan, Catherine and Schneider, Michael C and Griffin, Emily and Maier, Felicitas and Kiss, Courtney and Guerin, Andrea and Crosby, Kathleen and Rosenbaum, Kenneth and Tanpaiboon, Pranoot and Whalen, Sandra and Keren, Boris and McCarrier, Julie and Basel, Donald and Sadedin, Simon and White, Susan M and Delatycki, Martin B and Kleefstra, Tjitske and K{\"u}ry, S{\'e}bastien and Brusco, Alfredo and Sukarova-Angelovska, Elena and Trajkova, Slavica and Yoon, Sehoun and Wood, Stephen A and Piper, Michael and Penzes, Peter and Gecz, Jozef} } @article {912, title = {Phenotypic spectrum and transcriptomic profile associated with germline variants in TRAF7.}, journal = {Genet Med}, volume = {22}, year = {2020}, month = {2020 07}, pages = {1215-1226}, abstract = {

PURPOSE: Somatic variants in tumor necrosis factor receptor-associated factor 7 (TRAF7) cause meningioma, while germline variants have recently been identified in seven patients with developmental delay and cardiac, facial, and digital anomalies. We aimed to define the clinical and mutational spectrum associated with TRAF7 germline variants in a large series of patients, and to determine the molecular effects of the variants through transcriptomic analysis of patient fibroblasts.

METHODS: We performed exome, targeted capture, and Sanger sequencing of patients with undiagnosed developmental disorders, in multiple independent diagnostic or research centers. Phenotypic and mutational comparisons were facilitated through data exchange platforms. Whole-transcriptome sequencing was performed on RNA from patient- and control-derived fibroblasts.

RESULTS: We identified heterozygous missense variants in TRAF7 as the cause of a developmental delay-malformation syndrome in 45 patients. Major features include a recognizable facial gestalt (characterized in particular by blepharophimosis), short neck, pectus carinatum, digital deviations, and patent ductus arteriosus. Almost all variants occur in the WD40 repeats and most are recurrent. Several differentially expressed genes were identified in patient fibroblasts.

CONCLUSION: We provide the first large-scale analysis of the clinical and mutational spectrum associated with the TRAF7 developmental syndrome, and we shed light on its molecular etiology through transcriptome studies.

}, keywords = {Exome, Germ Cells, Humans, Intellectual Disability, Mutation, Missense, Phenotype, Transcriptome, Tumor Necrosis Factor Receptor-Associated Peptides and Proteins}, issn = {1530-0366}, doi = {10.1038/s41436-020-0792-7}, author = {Castilla-Vallmanya, Laura and Selmer, Kaja K and Dimartino, Cl{\'e}mantine and Rabionet, Raquel and Blanco-S{\'a}nchez, Bernardo and Yang, Sandra and Reijnders, Margot R F and van Essen, Antonie J and Oufadem, Myriam and Vigeland, Magnus D and Stadheim, Barbro and Houge, Gunnar and Cox, Helen and Kingston, Helen and Clayton-Smith, Jill and Innis, Jeffrey W and Iascone, Maria and Cereda, Anna and Gabbiadini, Sara and Chung, Wendy K and Sanders, Victoria and Charrow, Joel and Bryant, Emily and Millichap, John and Vitobello, Antonio and Thauvin, Christel and Mau-Them, Frederic Tran and Faivre, Laurence and Lesca, Gaetan and Labalme, Audrey and Rougeot, Christelle and Chatron, Nicolas and Sanlaville, Damien and Christensen, Katherine M and Kirby, Amelia and Lewandowski, Raymond and Gannaway, Rachel and Aly, MAH and Lehman, Anna and Clarke, Lorne and Graul-Neumann, Luitgard and Zweier, Christiane and Lessel, Davor and Lozic, Bernarda and Aukrust, Ingvild and Peretz, Ryan and Stratton, Robert and Smol, Thomas and Dieux-Co{\"e}slier, Anne and Meira, Joanna and Wohler, Elizabeth and Sobreira, Nara and Beaver, Erin M and Heeley, Jennifer and Briere, Lauren C and High, Frances A and Sweetser, David A and Walker, Melissa A and Keegan, Catherine E and Jayakar, Parul and Shinawi, Marwan and Kerstjens-Frederikse, Wilhelmina S and Earl, Dawn L and Siu, Victoria M and Reesor, Emma and Yao, Tony and Hegele, Robert A and Vaske, Olena M and Rego, Shannon and Shapiro, Kevin A and Wong, Brian and Gambello, Michael J and McDonald, Marie and Karlowicz, Danielle and Colombo, Roberto and Serretti, Alessandro and Pais, Lynn and O{\textquoteright}Donnell-Luria, Anne and Wray, Alison and Sadedin, Simon and Chong, Belinda and Tan, Tiong Y and Christodoulou, John and White, Susan M and Slavotinek, Anne and Barbouth, Deborah and Morel Swols, Dayna and Parisot, M{\'e}lanie and Bole-Feysot, Christine and Nitschk{\'e}, Patrick and Pingault, V{\'e}ronique and Munnich, Arnold and Cho, Megan T and Cormier-Daire, Val{\'e}rie and Balcells, Susanna and Lyonnet, Stanislas and Grinberg, Daniel and Amiel, Jeanne and Urreizti, Roser and Gordon, Christopher T} } @article {582, title = {Cerebral hypomyelination associated with biallelic variants of FIG4.}, journal = {Hum Mutat}, volume = {40}, year = {2019}, month = {2019 05}, pages = {619-630}, abstract = {

The lipid phosphatase gene FIG4 is responsible for Yunis-Var{\'o}n syndrome and Charcot-Marie-Tooth disease Type 4J, a peripheral neuropathy. We now describe four families with FIG4 variants and prominent abnormalities of central nervous system (CNS) white matter (leukoencephalopathy), with onset in early childhood, ranging from severe hypomyelination to mild undermyelination, in addition to peripheral neuropathy. Affected individuals inherited biallelic FIG4 variants from heterozygous parents. Cultured fibroblasts exhibit enlarged vacuoles characteristic of FIG4 dysfunction. Two unrelated families segregate the same G > A variant in the +1 position of intron 21 in the homozygous state in one family and compound heterozygous in the other. This mutation in the splice donor site of exon 21 results in read-through from exon 20 into intron 20 and truncation of the final 115 C-terminal amino acids of FIG4, with retention of partial function. The observed CNS white matter disorder in these families is consistent with the myelination defects in the FIG4 null mouse and the known role of FIG4 in oligodendrocyte maturation. The families described here the expanded clinical spectrum of FIG4 deficiency to include leukoencephalopathy.

}, issn = {1098-1004}, doi = {10.1002/humu.23720}, author = {Lenk, Guy M and Berry, Ian R and Stutterd, Chloe A and Blyth, Moira and Green, Lydia and Vadlamani, Gayatri and Warren, Daniel and Craven, Ian and Fanjul-Fernandez, Miriam and Rodriguez-Casero, Victoria and Lockhart, Paul J and Vanderver, Adeline and Simons, Cas and Gibb, Susan and Sadedin, Simon and White, Susan M and Christodoulou, John and Skibina, Olga and Ruddle, Jonathan and Tan, Tiong Y and Leventer, Richard J and Livingston, John H and Meisler, Miriam H} } @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} }