@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 {712, title = {A diagnostic ceiling for exome sequencing in cerebellar ataxia and related neurological disorders.}, journal = {Hum Mutat}, volume = {41}, year = {2020}, month = {2020 02}, pages = {487-501}, abstract = {

Genetic ataxias are associated with mutations in hundreds of genes with high phenotypic overlap complicating the clinical diagnosis. Whole-exome sequencing (WES) has increased the overall diagnostic rate considerably. However, the upper limit of this method remains ill-defined, hindering efforts to address the remaining diagnostic gap. To further assess the role of rare coding variation in ataxic disorders, we reanalyzed our previously published exome cohort of 76 predominantly adult and sporadic-onset patients, expanded the total number of cases to 260, and introduced analyses for copy number variation and repeat expansion in a representative subset. For new cases (n = 184), our resulting clinically relevant detection rate remained stable at 47\% with 24\% classified as pathogenic. Reanalysis of the previously sequenced 76 patients modestly improved the pathogenic rate by 7\%. For the combined cohort (n = 260), the total observed clinical detection rate was 52\% with 25\% classified as pathogenic. Published studies of similar neurological phenotypes report comparable rates. This consistency across multiple cohorts suggests that, despite continued technical and analytical advancements, an approximately 50\% diagnostic rate marks a relative ceiling for current WES-based methods and a more comprehensive genome-wide assessment is needed to identify the missing causative genetic etiologies for cerebellar ataxia and related neurodegenerative diseases.

}, issn = {1098-1004}, doi = {10.1002/humu.23946}, author = {Ngo, Kathie J and Rexach, Jessica E and Lee, Hane and Petty, Lauren E and Perlman, Susan and Valera, Juliana M and Deignan, Joshua L and Mao, Yuanming and Aker, Mamdouh and Posey, Jennifer E and Jhangiani, Shalini N and Coban-Akdemir, Zeynep H and Boerwinkle, Eric and Muzny, Donna and Nelson, Alexandra B and Hassin-Baer, Sharon and Poke, Gemma and Neas, Katherine and Geschwind, Michael D and Grody, Wayne W and Gibbs, Richard and Geschwind, Daniel H and Lupski, James R and Below, Jennifer E and Nelson, Stanley F and Fogel, Brent L} } @article {920, title = {KMT2B-related disorders: expansion of the phenotypic spectrum and long-term efficacy of deep brain stimulation.}, journal = {Brain}, volume = {143}, year = {2020}, month = {2020 12 05}, pages = {3242-3261}, abstract = {

Heterozygous mutations in KMT2B are associated with an early-onset, progressive and often complex dystonia (DYT28). Key characteristics of typical disease include focal motor features at disease presentation, evolving through a caudocranial pattern into generalized dystonia, with prominent oromandibular, laryngeal and cervical involvement. Although KMT2B-related disease is emerging as one of the most common causes of early-onset genetic dystonia, much remains to be understood about the full spectrum of the disease. We describe a cohort of 53 patients with KMT2B mutations, with detailed delineation of their clinical phenotype and molecular genetic features. We report new disease presentations, including atypical patterns of dystonia evolution and a subgroup of patients with a non-dystonic neurodevelopmental phenotype. In addition to the previously reported systemic features, our study has identified co-morbidities, including the risk of status dystonicus, intrauterine growth retardation, and endocrinopathies. Analysis of this study cohort (n = 53) in tandem with published cases (n = 80) revealed that patients with chromosomal deletions and protein truncating variants had a significantly higher burden of systemic disease (with earlier onset of dystonia) than those with missense variants. Eighteen individuals had detailed longitudinal data available after insertion of deep brain stimulation for medically refractory dystonia. Median age at deep brain stimulation was 11.5 years (range: 4.5-37.0 years). Follow-up after deep brain stimulation ranged from 0.25 to 22 years. Significant improvement of motor function and disability (as assessed by the Burke Fahn Marsden{\textquoteright}s Dystonia Rating Scales, BFMDRS-M and BFMDRS-D) was evident at 6 months, 1 year and last follow-up (motor, P = 0.001, P = 0.004, and P = 0.012; disability, P = 0.009, P = 0.002 and P = 0.012). At 1 year post-deep brain stimulation, >50\% of subjects showed BFMDRS-M and BFMDRS-D improvements of >30\%. In the long-term deep brain stimulation cohort (deep brain stimulation inserted for >5 years, n = 8), improvement of >30\% was maintained in 5/8 and 3/8 subjects for the BFMDRS-M and BFMDRS-D, respectively. The greatest BFMDRS-M improvements were observed for trunk (53.2\%) and cervical (50.5\%) dystonia, with less clinical impact on laryngeal dystonia. Improvements in gait dystonia decreased from 20.9\% at 1 year to 16.2\% at last assessment; no patient maintained a fully independent gait. Reduction of BFMDRS-D was maintained for swallowing (52.9\%). Five patients developed mild parkinsonism following deep brain stimulation. KMT2B-related disease comprises an expanding continuum from infancy to adulthood, with early evidence of genotype-phenotype correlations. Except for laryngeal dysphonia, deep brain stimulation provides a significant improvement in quality of life and function with sustained clinical benefit depending on symptoms distribution.

}, keywords = {Adolescent, Adult, Child, Child, Preschool, Chromosome Deletion, Cohort Studies, Computer Simulation, Deep Brain Stimulation, Disease Progression, Dystonic Disorders, Endocrine System Diseases, Female, Fetal Growth Retardation, Gait Disorders, Neurologic, Histone-Lysine N-Methyltransferase, Humans, Laryngeal Diseases, Male, Mutation, Mutation, Missense, Phenotype, Quality of Life, Treatment Outcome, Young Adult}, issn = {1460-2156}, doi = {10.1093/brain/awaa304}, author = {Cif, Laura and Demailly, Diane and Lin, Jean-Pierre and Barwick, Katy E and Sa, Mario and Abela, Lucia and Malhotra, Sony and Chong, Wui K and Steel, Dora and Sanchis-Juan, Alba and Ngoh, Adeline and Trump, Natalie and Meyer, Esther and Vasques, Xavier and Rankin, Julia and Allain, Meredith W and Applegate, Carolyn D and Attaripour IsfAHni, Sanaz and Baleine, Julien and Balint, Bettina and Bassetti, Jennifer A and Baple, Emma L and Bhatia, Kailash P and Blanchet, Catherine and Burglen, Lydie and Cambonie, Gilles and Seng, Emilie Chan and Bastaraud, Sandra Chantot and Cyprien, Fabienne and Coubes, Christine and d{\textquoteright}Hardemare, Vincent and Doja, Asif and Dorison, Nathalie and Doummar, Diane and Dy-Hollins, Marisela E and Farrelly, Ellyn and FitzPatrick, David R and Fearon, Conor and Fieg, Elizabeth L and Fogel, Brent L and Forman, Eva B and Fox, Rachel G and Gahl, William A and Galosi, Serena and Gonzalez, Victoria and Graves, Tracey D and Gregory, Allison and Hallett, Mark and Hasegawa, Harutomo and Hayflick, Susan J and Hamosh, Ada and Hully, Marie and Jansen, Sandra and Jeong, Suh Young and Krier, Joel B and Krystal, Sidney and Kumar, Kishore R and Laurencin, Chlo{\'e} and Lee, Hane and Lesca, Gaetan and Fran{\c c}ois, Laurence Lion and Lynch, Timothy and MAHnt, Neil and Martinez-Agosto, Julian A and Milesi, Christophe and Mills, Kelly A and Mondain, Michel and Morales-Briceno, Hugo and Ostergaard, John R and Pal, Swasti and Pallais, Juan C and Pavillard, Fr{\'e}d{\'e}rique and Perrigault, Pierre-Francois and Petersen, Andrea K and Polo, Gustavo and Poulen, Gaetan and Rinne, Tuula and Roujeau, Thomas and Rogers, Caleb and Roubertie, Agathe and SAHgian, Michelle and Schaefer, Elise and Selim, Laila and Selway, Richard and Sharma, Nutan and Signer, Rebecca and Soldatos, Ariane G and Stevenson, David A and Stewart, Fiona and Tchan, Michel and Verma, Ishwar C and de Vries, Bert B A and Wilson, Jenny L and Wong, Derek A and Zaitoun, Raghda and Zhen, Dolly and Znaczko, Anna and Dale, Russell C and de Gusm{\~a}o, Claudio M and Friedman, Jennifer and Fung, Victor S C and King, Mary D and Mohammad, Shekeeb S and Rohena, Luis and Waugh, Jeff L and Toro, Camilo and Raymond, F Lucy and Topf, Maya and Coubes, Philippe and Gorman, Kathleen M and Kurian, Manju A} } @article {334, title = {A Recurrent De Novo Variant in NACC1 Causes a Syndrome Characterized by Infantile Epilepsy, Cataracts, and Profound Developmental Delay.}, journal = {Am J Hum Genet}, volume = {100}, year = {2017}, month = {2017 Feb 02}, pages = {343-351}, abstract = {

Whole-exome sequencing (WES) has increasingly enabled new pathogenic gene variant identification for undiagnosed neurodevelopmental disorders and provided insights into both gene function and disease biology. Here, we describe seven children with a neurodevelopmental disorder characterized by microcephaly, profound developmental delays and/or intellectual disability, cataracts, severe epilepsy including infantile spasms, irritability, failure to thrive, and stereotypic hand movements. Brain imaging in these individuals reveals delay in myelination and cerebral atrophy. We observe an identical recurrent de novo heterozygous c.892C>T (p.Arg298Trp) variant in the nucleus accumbens associated 1 (NACC1) gene in seven affected individuals. One of the seven individuals is mosaic for this variant. NACC1 encodes a transcriptional repressor implicated in gene expression and has not previously been associated with germline disorders. The probability of finding the same missense NACC1 variant by chance in 7 out of 17,228 individuals who~underwent WES for diagnoses of neurodevelopmental phenotypes is extremely small and achieves genome-wide significance (p~= 1.25~{\texttimes} 10). Selective constraint against missense variants in NACC1 makes this excess of an identical missense variant in all seven individuals more remarkable. Our findings are consistent with a germline recurrent mutational hotspot associated with an allele-specific neurodevelopmental phenotype in NACC1.

}, keywords = {Alleles, Amino Acid Sequence, Brain, Cataract, Child, Child, Preschool, Female, Genetic Variation, Genome-Wide Association Study, Humans, Infant, Intellectual Disability, Magnetic Resonance Imaging, Male, Microcephaly, Mutation, Missense, Neoplasm Proteins, Pedigree, Phenotype, Repressor Proteins, Spasms, Infantile}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.12.013}, author = {Schoch, Kelly and Meng, Linyan and Szelinger, Szabolcs and Bearden, David R and Stray-Pedersen, Asbjorg and Busk, Oyvind L and Stong, Nicholas and Liston, Eriskay and Cohn, Ronald D and Scaglia, Fernando and Rosenfeld, Jill A and Tarpinian, Jennifer and Skraban, Cara M and Deardorff, Matthew A and Friedman, Jeremy N and Akdemir, Zeynep Coban and Walley, Nicole and Mikati, Mohamad A and Kranz, Peter G and Jasien, Joan and McConkie-Rosell, Allyn and McDonald, Marie and Wechsler, Stephanie Burns and Freemark, Michael and Kansagra, Sujay and Freedman, Sharon and Bali, Deeksha and Millan, Francisca and Bale, Sherri and Nelson, Stanley F and Lee, Hane and Dorrani, Naghmeh and Goldstein, David B and Xiao, Rui and Yang, Yaping and Posey, Jennifer E and Martinez-Agosto, Julian A and Lupski, James R and Wangler, Michael F and Shashi, Vandana} } @article {162, title = {A second locus for Schneckenbecken dysplasia identified by a mutation in the gene encoding inositol polyphosphate phosphatase-like 1 (INPPL1).}, journal = {Am J Med Genet A}, volume = {167A}, year = {2015}, month = {2015 Oct}, pages = {2470-3}, keywords = {Exome, Gene Expression, Genetic Loci, Gestational Age, Homozygote, Humans, Hydrops Fetalis, Infant, Newborn, Male, Mutation, Osteochondrodysplasias, Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases, Phosphoric Monoester Hydrolases, Stillbirth}, issn = {1552-4833}, doi = {10.1002/ajmg.a.37173}, author = {Lee, Hane and Nevarez, Lisette and Lachman, Ralph S and Wilcox, William R and Krakow, Deborah and Cohn, Daniel H} } @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} }