@article {738, title = {Deficiencies in vesicular transport mediated by TRAPPC4 are associated with severe syndromic intellectual disability.}, journal = {Brain}, volume = {143}, year = {2020}, month = {2020 01 01}, pages = {112-130}, abstract = {

The conserved transport protein particle (TRAPP) complexes regulate key trafficking events and are required for autophagy. TRAPPC4, like its yeast Trs23 orthologue, is a core component of the TRAPP complexes and one of the essential subunits for guanine nucleotide exchange factor activity for Rab1 GTPase. Pathogenic variants in specific TRAPP subunits are associated with neurological disorders. We undertook exome sequencing in three unrelated families of Caucasian, Turkish and French-Canadian ethnicities with seven affected children that showed features of early-onset seizures, developmental delay, microcephaly, sensorineural deafness, spastic quadriparesis and progressive cortical and cerebellar atrophy in an effort to determine the genetic aetiology underlying neurodevelopmental disorders. All seven affected subjects shared the same identical rare, homozygous, potentially pathogenic variant in a non-canonical, well-conserved splice site within TRAPPC4 (hg19:chr11:g.118890966A>G; TRAPPC4: NM_016146.5; c.454+3A>G). Single nucleotide polymorphism array analysis revealed there was no haplotype shared between the tested Turkish and Caucasian families suggestive of a variant hotspot region rather than a founder effect. In silico analysis predicted the variant to cause aberrant splicing. Consistent with this, experimental evidence showed both a reduction in full-length transcript levels and an increase in levels of a shorter transcript missing exon 3, suggestive of an incompletely penetrant splice defect. TRAPPC4 protein levels were significantly reduced whilst levels of other TRAPP complex subunits remained unaffected. Native polyacrylamide gel electrophoresis and size exclusion chromatography demonstrated a defect in TRAPP complex assembly and/or stability. Intracellular trafficking through the Golgi using the marker protein VSVG-GFP-ts045 demonstrated significantly delayed entry into and exit from the Golgi in fibroblasts derived from one of the affected subjects. Lentiviral expression of wild-type TRAPPC4 in these fibroblasts restored trafficking, suggesting that the trafficking defect was due to reduced TRAPPC4 levels. Consistent with the recent association of the TRAPP complex with autophagy, we found that the fibroblasts had a basal autophagy defect and a delay in autophagic flux, possibly due to unsealed autophagosomes. These results were validated using a yeast trs23 temperature sensitive variant that exhibits constitutive and stress-induced autophagic defects at permissive temperature and a secretory defect at restrictive temperature. In summary we provide strong evidence for pathogenicity of this variant in a member of the core TRAPP subunit, TRAPPC4 that associates with vesicular trafficking and autophagy defects. This is the first report of a TRAPPC4 variant, and our findings add to the growing number of TRAPP-associated neurological disorders.

}, keywords = {Atrophy, Autophagy, Cerebellum, Cerebral Cortex, Child, Child, Preschool, Craniofacial Abnormalities, Deafness, Developmental Disabilities, Epilepsy, Female, Fibroblasts, Hearing Loss, Sensorineural, Humans, Infant, Infant, Newborn, Intellectual Disability, Male, Microcephaly, Microscopy, Fluorescence, Muscle Spasticity, Nerve Tissue Proteins, Neurodevelopmental Disorders, Pedigree, Quadriplegia, RNA Splice Sites, Syndrome, Vesicular Transport Proteins}, issn = {1460-2156}, doi = {10.1093/brain/awz374}, author = {Van Bergen, Nicole J and Guo, Yiran and Al-Deri, Noraldin and Lipatova, Zhanna and Stanga, Daniela and Zhao, Sarah and Murtazina, Rakhilya and Gyurkovska, Valeriya and Pehlivan, Davut and Mitani, Tadahiro and Gezdirici, Alper and Antony, Jayne and Collins, Felicity and Willis, Mary J H and Coban Akdemir, Zeynep H and Liu, Pengfei and Punetha, Jaya and Hunter, Jill V and Jhangiani, Shalini N and Fatih, Jawid M and Rosenfeld, Jill A and Posey, Jennifer E and Gibbs, Richard A and Karaca, Ender and Massey, Sean and Ranasinghe, Thisara G and Sleiman, Patrick and Troedson, Chris and Lupski, James R and Sacher, Michael and Segev, Nava and Hakonarson, Hakon and Christodoulou, John} } @article {757, title = {Gomez-L{\'o}pez-Hern{\'a}ndez syndrome: A case report with clinical and molecular evaluation and literature review.}, journal = {Am J Med Genet A}, volume = {182}, year = {2020}, month = {2020 07}, pages = {1761-1766}, abstract = {

Gomez-L{\'o}pez-Hern{\'a}ndez syndrome (GLHS) is characterized by rhombencephalosynapsis (RES), alopecia, trigeminal anesthesia and a distinctive phenotype, including brachyturricephaly. It has been suggested that GLHS should be considered as part of the spectrum of RES-associated conditions that include alopecia, trigeminal anesthesia, and craniofacial anomalies, rather than a distinct entity. To the best of our knowledge, 57 patients with GLHS have been described. Despite its first description in 1979, the etiology of this syndrome remains unknown. Here, we describe, to our knowledge, the first case of a patient with GLHS who was molecularly evaluated and had been prenatally exposed to misoprostol. We also reviewed the clinical and morphological features of the patients described to date to better delineate the phenotype and focus on any evidence for adverse pregnancy outcomes or exposure, including teratogens.

}, keywords = {Abnormalities, Multiple, Alopecia, Cerebellum, Child, Child, Preschool, Craniofacial Abnormalities, Female, Growth Disorders, Humans, Magnetic Resonance Imaging, Misoprostol, Neurocutaneous Syndromes, Phenotype, Rhombencephalon, Trigeminal Nerve}, issn = {1552-4833}, doi = {10.1002/ajmg.a.61594}, author = {Perrone, Eduardo and D{\textquoteright}Almeida, V{\^a}nia and de Macena Sobreira, Nara Lygia and de Mello, Claudia Berlim and de Oliveira, Allan Chiaratti and Burlin, St{\^e}nio and Soares, Maria de F{\'a}tima de Faria and Cernach, Mirlene Cec{\'\i}lia Soares Pinho and Alvarez Perez, Ana Beatriz} } @article {770, title = {MN1 C-terminal truncation syndrome is a novel neurodevelopmental and craniofacial disorder with partial rhombencephalosynapsis.}, journal = {Brain}, volume = {143}, year = {2020}, month = {2020 01 01}, pages = {55-68}, abstract = {

MN1 encodes a transcriptional co-regulator without homology to other proteins, previously implicated in acute myeloid leukaemia and development of the palate. Large deletions encompassing MN1 have been reported in individuals with variable neurodevelopmental anomalies and non-specific facial features. We identified a cluster of de novo truncating mutations in MN1 in a cohort of 23 individuals with strikingly similar dysmorphic facial features, especially midface hypoplasia, and intellectual disability with severe expressive language delay. Imaging revealed an atypical form of rhombencephalosynapsis, a distinctive brain malformation characterized by partial or complete loss of the cerebellar vermis with fusion of the cerebellar hemispheres, in 8/10 individuals. Rhombencephalosynapsis has no previously known definitive genetic or environmental causes. Other frequent features included perisylvian polymicrogyria, abnormal posterior clinoid processes and persistent trigeminal artery. MN1 is encoded by only two exons. All mutations, including the recurrent variant p.Arg1295* observed in 8/21 probands, fall in the terminal exon or the extreme 3{\textquoteright} region of exon 1, and are therefore predicted to result in escape from nonsense-mediated mRNA decay. This was confirmed in fibroblasts from three individuals. We propose that the condition described here, MN1 C-terminal truncation (MCTT) syndrome, is not due to MN1 haploinsufficiency but rather is the result of dominantly acting C-terminally truncated MN1 protein. Our data show that MN1 plays a critical role in human craniofacial and brain development, and opens the door to understanding the biological mechanisms underlying rhombencephalosynapsis.

}, keywords = {Abnormalities, Multiple, Adolescent, Basilar Artery, Carotid Arteries, Cerebellar Vermis, Cerebellum, Child, Child, Preschool, Cohort Studies, Comparative Genomic Hybridization, Craniofacial Abnormalities, Female, Fibroblasts, Humans, Imaging, Three-Dimensional, Infant, Intellectual Disability, Language Development Disorders, Magnetic Resonance Imaging, Male, Middle Aged, Mutation, Nervous System Malformations, Nonsense Mediated mRNA Decay, Polymicrogyria, Real-Time Polymerase Chain Reaction, RNA-Seq, Syndrome, Tomography, X-Ray Computed, Trans-Activators, Tumor Suppressor Proteins, Whole Exome Sequencing, Whole Genome Sequencing}, issn = {1460-2156}, doi = {10.1093/brain/awz379}, author = {Mak, Christopher C Y and Doherty, Dan and Lin, Angela E and Vegas, Nancy and Cho, Megan T and Viot, G{\'e}raldine and Dimartino, Cl{\'e}mantine and Weisfeld-Adams, James D and Lessel, Davor and Joss, Shelagh and Li, Chumei and Gonzaga-Jauregui, Claudia and Zarate, Yuri A and Ehmke, Nadja and Horn, Denise and Troyer, Caitlin and Kant, Sarina G and Lee, Youngha and Ishak, Gisele E and Leung, Gordon and Barone Pritchard, Amanda and Yang, Sandra and Bend, Eric G and Filippini, Francesca and Roadhouse, Chelsea and Lebrun, Nicolas and Mehaffey, Michele G and Martin, Pierre-Marie and Apple, Benjamin and Millan, Francisca and Puk, Oliver and Hoffer, Mariette J V and Henderson, Lindsay B and McGowan, Ruth and Wentzensen, Ingrid M and Pei, Steven and Zahir, Farah R and Yu, Mullin and Gibson, William T and Seman, Ann and Steeves, Marcie and Murrell, Jill R and Luettgen, Sabine and Francisco, Elizabeth and Strom, Tim M and Amlie-Wolf, Louise and Kaindl, Angela M and Wilson, William G and Halbach, Sara and Basel-Salmon, Lina and Lev-El, Noa and Denecke, Jonas and Vissers, Lisenka E L M and Radtke, Kelly and Chelly, Jamel and Zackai, Elaine and Friedman, Jan M and Bamshad, Michael J and Nickerson, Deborah A and Reid, Russell R and Devriendt, Koenraad and Chae, Jong-Hee and Stolerman, Elliot and McDougall, Carey and Powis, Z{\"o}e and Bienvenu, Thierry and Tan, Tiong Y and Orenstein, Naama and Dobyns, William B and Shieh, Joseph T and Choi, Murim and Waggoner, Darrel and Gripp, Karen W and Parker, Michael J and Stoler, Joan and Lyonnet, Stanislas and Cormier-Daire, Val{\'e}rie and Viskochil, David and Hoffman, Trevor L and Amiel, Jeanne and Chung, Brian H Y and Gordon, Christopher T} } @article {966, title = {Successful treatment of intractable epilepsy with ketogenic diet therapy in twins with ALG3-CDG.}, journal = {Brain Dev}, volume = {42}, year = {2020}, month = {2020 Aug}, pages = {539-545}, abstract = {

BACKGROUND: Congenital disorders of glycosylation (CDG) is a heterogeneous group of congenital metabolic diseases with multisystem clinical involvement. ALG3-CDG is a very rare subtype with only 24 cases reported so far.

CASE: Here, we report two siblings with dysmorphic features, growth retardation, microcephaly, intractable epilepsy, and hemangioma in the frontal, occipital and lumbosacral regions.

RESULTS: We studied two siblings by whole exome sequencing. A pathogenic variant in ALG3 (NM_005787.6: c.165C~>~T; p.Gly55=) that had been previously associated with congenital glycolysis defect type 1d was identified. Their intractable seizures were controlled by ketogenic diet.

CONCLUSION: Although prominent findings of growth retardation and microcephaly seen in our patients have been extensively reported before, presence of hemangioma is a novel finding that may be used as an indication for ALG3-CDG diagnosis. Our patients are the first reported cases whose intractable seizures were controlled with ketogenic diet. This report adds ketogenic diet as an option for treatment of intractable epilepsy in ALG3-CDG.

}, keywords = {Central Nervous System Neoplasms, Congenital Disorders of Glycosylation, Craniofacial Abnormalities, Developmental Disabilities, Diet, Ketogenic, Drug Resistant Epilepsy, Female, Hemangioma, Humans, Infant, Male, Mannosyltransferases, Twins, Whole Exome Sequencing}, issn = {1872-7131}, doi = {10.1016/j.braindev.2020.04.008}, author = {Paketci, C and Edem, P and Hiz, S and Sonmezler, E and Soydemir, D and Sarikaya Uzan, G and Oktay, Y and O{\textquoteright}Heir, E and Beltran, S and Laurie, S and T{\"o}pf, A and Lochmuller, H and Horvath, R and Yis, U} } @article {580, title = {De novo and inherited TCF20 pathogenic variants are associated with intellectual disability, dysmorphic features, hypotonia, and neurological impairments with similarities to Smith-Magenis syndrome.}, journal = {Genome Med}, volume = {11}, year = {2019}, month = {2019 02 28}, pages = {12}, abstract = {

BACKGROUND: Neurodevelopmental disorders are genetically and phenotypically heterogeneous encompassing developmental delay (DD), intellectual disability (ID), autism spectrum disorders (ASDs), structural brain abnormalities, and neurological manifestations with variants in a large number of genes (hundreds) associated. To date, a few de novo mutations potentially disrupting TCF20 function in patients with ID, ASD, and hypotonia have been reported. TCF20 encodes a transcriptional co-regulator structurally related to RAI1, the dosage-sensitive gene responsible for Smith-Magenis syndrome (deletion/haploinsufficiency) and Potocki-Lupski syndrome (duplication/triplosensitivity).

METHODS: Genome-wide analyses by exome sequencing (ES) and chromosomal microarray analysis (CMA) identified individuals with heterozygous, likely damaging, loss-of-function alleles in TCF20. We implemented further molecular and clinical analyses to determine the inheritance of the pathogenic variant alleles and studied the spectrum of phenotypes.

RESULTS: We report 25 unique inactivating single nucleotide variants/indels (1 missense, 1 canonical splice-site variant, 18 frameshift, and 5 nonsense) and 4 deletions of TCF20. The pathogenic variants were detected in 32 patients and 4 affected parents from 31 unrelated families. Among cases with available parental samples, the variants were de novo in 20 instances and inherited from 4 symptomatic parents in 5, including in one set of monozygotic twins. Two pathogenic loss-of-function variants were recurrent in unrelated families. Patients presented with a phenotype characterized by developmental delay, intellectual disability, hypotonia, variable dysmorphic features, movement disorders, and sleep disturbances.

CONCLUSIONS: TCF20 pathogenic variants are associated with a novel syndrome manifesting clinical characteristics similar to those observed in Smith-Magenis syndrome. Together with previously described cases, the clinical entity of TCF20-associated neurodevelopmental disorders (TAND) emerges from a genotype-driven perspective.

}, keywords = {Adolescent, Child, Child, Preschool, Craniofacial Abnormalities, Developmental Disabilities, Female, Humans, INDEL Mutation, Infant, Intellectual Disability, Male, Muscle Hypotonia, Smith-Magenis Syndrome, Transcription Factors, Young Adult}, issn = {1756-994X}, doi = {10.1186/s13073-019-0623-0}, author = {Vetrini, Francesco and McKee, Shane and Rosenfeld, Jill A and Suri, Mohnish and Lewis, Andrea M and Nugent, Kimberly Margaret and Roeder, Elizabeth and Littlejohn, Rebecca O and Holder, Sue and Zhu, Wenmiao and Alaimo, Joseph T and Graham, Brett and Harris, Jill M and Gibson, James B and Pastore, Matthew and McBride, Kim L and Komara, Makanko and Al-Gazali, Lihadh and Al Shamsi, Aisha and Fanning, Elizabeth A and Wierenga, Klaas J and Scott, Daryl A and Ben-Neriah, Ziva and Meiner, Vardiella and Cassuto, Hanoch and Elpeleg, Orly and Holder, J Lloyd and Burrage, Lindsay C and Seaver, Laurie H and Van Maldergem, Lionel and Mahida, Sonal and Soul, Janet S and Marlatt, Margaret and Matyakhina, Ludmila and Vogt, Julie and Gold, June-Anne and Park, Soo-Mi and Varghese, Vinod and Lampe, Anne K and Kumar, Ajith and Lees, Melissa and Holder-Espinasse, Muriel and McConnell, Vivienne and Bernhard, Birgitta and Blair, Ed and Harrison, Victoria and Muzny, Donna M and Gibbs, Richard A and Elsea, Sarah H and Posey, Jennifer E and Bi, Weimin and Lalani, Seema and Xia, Fan and Yang, Yaping and Eng, Christine M and Lupski, James R and Liu, Pengfei} } @article {446, title = {WNT Signaling Perturbations Underlie the Genetic Heterogeneity of Robinow Syndrome.}, journal = {Am J Hum Genet}, volume = {102}, year = {2018}, month = {2018 01 04}, pages = {27-43}, abstract = {

Locus heterogeneity characterizes a variety of skeletal dysplasias often due to interacting or overlapping signaling pathways. Robinow syndrome is a skeletal disorder historically refractory to molecular diagnosis, potentially stemming from substantial genetic heterogeneity. All current known pathogenic variants reside in genes within the noncanonical Wnt signaling pathway including ROR2, WNT5A, and more recently, DVL1 and DVL3. However, \~{}70\% of autosomal-dominant Robinow syndrome cases remain molecularly unsolved. To investigate this missing heritability, we recruited 21 families with at least one family member clinically diagnosed with Robinow or Robinow-like phenotypes and performed genetic and genomic studies. In total, four families with variants in FZD2 were identified as well as three individuals from two families with biallelic variants in NXN that co-segregate with the phenotype. Importantly, both FZD2 and NXN are relevant protein partners in the WNT5A interactome, supporting their role in skeletal development. In addition to confirming that clustered -1 frameshifting variants in DVL1 and DVL3 are the main contributors to dominant Robinow syndrome, we also found likely pathogenic variants in candidate genes GPC4 and RAC3, both linked to the Wnt signaling pathway. These data support an initial hypothesis that Robinow syndrome results from perturbation of the Wnt/PCP pathway, suggest specific relevant domains of the proteins involved, and reveal key contributors in this signaling cascade during human embryonic development. Contrary to the view that non-allelic genetic heterogeneity hampers gene discovery, this study demonstrates the utility of rare disease genomic studies to parse gene function in human developmental pathways.

}, keywords = {Adolescent, Adult, Base Sequence, Child, Child, Preschool, Chromosome Segregation, Craniofacial Abnormalities, Diagnosis, Differential, Dwarfism, Female, Genes, Dominant, Genetic Association Studies, Genetic Heterogeneity, Humans, Limb Deformities, Congenital, Male, Middle Aged, Mutation, Missense, Phenotype, Urogenital Abnormalities, Wnt Signaling Pathway}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2017.10.002}, author = {White, Janson J and Mazzeu, Juliana F and Coban-Akdemir, Zeynep and Bayram, Yavuz and Bahrambeigi, Vahid and Hoischen, Alexander and van Bon, Bregje W M and Gezdirici, Alper and Gulec, Elif Yilmaz and Ramond, Francis and Touraine, Renaud and Thevenon, Julien and Shinawi, Marwan and Beaver, Erin and Heeley, Jennifer and Hoover-Fong, Julie and Durmaz, Ceren D and Karabulut, Halil Gurhan and Marzioglu-Ozdemir, Ebru and Cayir, Atilla and Duz, Mehmet B and Seven, Mehmet and Price, Susan and Ferreira, Barbara Merfort and Vianna-Morgante, Angela M and Ellard, Sian and Parrish, Andrew and Stals, Karen and Flores-Daboub, Josue and Jhangiani, Shalini N and Gibbs, Richard A and Brunner, Han G and Sutton, V Reid and Lupski, James R and Carvalho, Claudia M B} } @article {358, title = {Germline mutations in ABL1 cause an autosomal dominant syndrome characterized by congenital heart defects and skeletal malformations.}, journal = {Nat Genet}, volume = {49}, year = {2017}, month = {2017 Apr}, pages = {613-617}, abstract = {

ABL1 is a proto-oncogene well known as part of the fusion gene BCR-ABL1 in the Philadelphia chromosome of leukemia cancer cells. Inherited germline ABL1 changes have not been associated with genetic disorders. Here we report ABL1 germline variants cosegregating with an autosomal dominant disorder characterized by congenital heart disease, skeletal abnormalities, and failure to thrive. The variant c.734A>G (p.Tyr245Cys) was found to occur de novo or cosegregate with disease in five individuals (families 1-3). Additionally, a de novo c.1066G>A (p.Ala356Thr) variant was identified in a sixth individual (family 4). We overexpressed the mutant constructs in HEK 293T cells and observed increased tyrosine phosphorylation, suggesting increased ABL1 kinase activities associated with both the p.Tyr245Cys and p.Ala356Thr substitutions. Our clinical and experimental findings, together with previously reported teratogenic effects of selective BCR-ABL inhibitors in humans and developmental defects in Abl1 knockout mice, suggest that ABL1 has an important role during organismal development.

}, keywords = {Abnormalities, Multiple, Animals, Bone Diseases, Developmental, Cell Line, Chromosome Disorders, Craniofacial Abnormalities, Feeding and Eating Disorders, Female, Fusion Proteins, bcr-abl, Germ-Line Mutation, Heart Defects, Congenital, HEK293 Cells, Humans, Leukemia, Myelogenous, Chronic, BCR-ABL Positive, Limb Deformities, Congenital, Male, Mice, Mice, Knockout, Philadelphia Chromosome, Phosphorylation, Signal Transduction}, issn = {1546-1718}, doi = {10.1038/ng.3815}, author = {Wang, Xia and Charng, Wu-Lin and Chen, Chun-An and Rosenfeld, Jill A and Al Shamsi, Aisha and Al-Gazali, Lihadh and McGuire, Marianne and Mew, Nicholas Ah and Arnold, Georgianne L and Qu, Chunjing and Ding, Yan and Muzny, Donna M and Gibbs, Richard A and Eng, Christine M and Walkiewicz, Magdalena and Xia, Fan and Plon, Sharon E and Lupski, James R and Schaaf, Christian P and Yang, Yaping} } @article {396, title = {A novel mutation in GMPPA in siblings with apparent intellectual disability, epilepsy, dysmorphism, and autonomic dysfunction.}, journal = {Am J Med Genet A}, volume = {173}, year = {2017}, month = {2017 Aug}, pages = {2246-2250}, abstract = {

GMPPA encodes the GDP-mannose pyrophosphorylase A protein (GMPPA). The function of GMPPA is not well defined, however it is a homolog of GMPPB which catalyzes the reaction that converts mannose-1-phosphate and guanosine-5{\textquoteright}-triphosphate to GDP-mannose. Previously, biallelic mutations in GMPPA were reported to cause a disorder characterized by achalasia, alacrima, neurological deficits, and intellectual disability. In this study, we report a female proband with achalasia, alacrima, hypohydrosis, apparent intellectual disability, seizures, microcephaly, esotropia, and craniofacial dysmorphism. Exome sequencing identified a previously unreported homozygous c.853+1G>A variant in GMPPA in the proband and her affected sister. Their unaffected parents were heterozygous, and unaffected brother homozygous wild type for this variant. Lymphoblast cells from the affected sisters showed complete loss of the GMPPA protein by Western blotting, and increased levels of GDP-mannose in lymphoblasts on high performance liquid chromatography. Based on our findings and the previous report describing patients with an overlapping phenotype, we conclude that this novel variant in GMPPA, identified by exome sequencing in the proband and her affected sister, is the genetic cause of their phenotype and may expand the known phenotype of this recently described glycosylation disorder.

}, keywords = {Abnormalities, Multiple, Child, Child, Preschool, Craniofacial Abnormalities, Epilepsy, Exome, Facies, Female, Heterozygote, Humans, Intellectual Disability, Microcephaly, Muscular Atrophy, Mutation, Missense, Nucleotidyltransferases, Pedigree, Phenotype, Seizures}, issn = {1552-4833}, doi = {10.1002/ajmg.a.38292}, author = {Gold, Wendy A and Sobreira, Nara and Wiame, Elsa and Marbaix, Alexandre and Van Schaftingen, Emile and Franzka, Patricia and Riley, Lisa G and Worgan, Lisa and H{\"u}bner, Christian A and Christodoulou, John and Ad{\`e}s, Lesley C} } @article {79, title = {DVL3 Alleles Resulting in a -1 Frameshift of the Last Exon Mediate Autosomal-Dominant Robinow Syndrome.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 Mar 03}, pages = {553-561}, abstract = {

Robinow syndrome is a rare congenital disorder characterized by mesomelic limb shortening, genital hypoplasia, and distinctive facial features. Recent reports have identified, in individuals with dominant Robinow syndrome, a specific type of variant characterized by being uniformly located in the penultimate exon of DVL1 and resulting in a -1 frameshift allele with a premature termination codon that escapes nonsense-mediated decay. Here, we studied a cohort of individuals who had been clinically diagnosed with Robinow syndrome but who had not received a molecular diagnosis from variant studies of DVL1, WNT5A, and ROR2. Because of the uniform location of frameshift variants in DVL1-mediated Robinow syndrome and the functional redundancy of DVL1, DVL2, and DVL3, we elected to pursue direct Sanger sequencing of the penultimate exon of DVL1 and its paralogs DVL2 and DVL3 to search for potential disease-associated variants. Remarkably, targeted sequencing identified five unrelated individuals harboring heterozygous, de novo frameshift variants in DVL3, including two splice acceptor mutations and three 1 bp deletions. Similar to the variants observed in DVL1-mediated Robinow syndrome, all variants in DVL3 result in a -1 frameshift, indicating that these highly specific alterations might be a common cause of dominant Robinow syndrome. Here, we review the current knowledge of these peculiar variant alleles in DVL1- and DVL3-mediated Robinow syndrome and further elucidate the phenotypic features present in subjects with DVL1 and DVL3 frameshift mutations.

}, keywords = {Adaptor Proteins, Signal Transducing, Alleles, Base Sequence, Codon, Nonsense, Craniofacial Abnormalities, Dishevelled Proteins, Dwarfism, Exons, Female, Frameshift Mutation, Genetic Variation, Humans, Limb Deformities, Congenital, Male, Molecular Sequence Data, Phosphoproteins, Proto-Oncogene Proteins, Receptor Tyrosine Kinase-like Orphan Receptors, Sequence Analysis, DNA, Sequence Deletion, Urogenital Abnormalities, Wnt Proteins, Wnt-5a Protein}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.01.005}, author = {White, Janson J and Mazzeu, Juliana F and Hoischen, Alexander and Bayram, Yavuz and Withers, Marjorie and Gezdirici, Alper and Kimonis, Virginia and Steehouwer, Marloes and Jhangiani, Shalini N and Muzny, Donna M and Gibbs, Richard A and van Bon, Bregje W M and Sutton, V Reid and Lupski, James R and Brunner, Han G and Carvalho, Claudia M B} } @article {531, title = {Update on the Toriello-Carey syndrome.}, journal = {Am J Med Genet A}, volume = {170}, year = {2016}, month = {2016 10}, pages = {2551-8}, abstract = {

Toriello and Carey described a provisionally-unique syndrome comprised of agenesis of the corpus callosum, Pierre Robin anomaly, and a characteristic facial phenotype. Because the condition affected siblings, this entity was postulated to be an autosomal recessive multiple anomaly syndrome. Several patients were subsequently reported, and over time, it became apparent that the Toriello-Carey syndrome was etiologically heterogeneous. Based on previous reports, it is estimated that at least 20\% of patients with a clinical diagnosis of Toriello-Carey syndrome have a chromosomal anomaly as the basis of the phenotype. However, no basis for the non-chromosomal cases has been found. This review summarizes the literature to date and provides speculation regarding the possible explanations for failing to find the cause of Toriello-Carey syndrome. {\textcopyright} 2016 Wiley Periodicals, Inc.

}, keywords = {Agenesis of Corpus Callosum, Chromosome Aberrations, Craniofacial Abnormalities, Female, Genetic Association Studies, Heart Defects, Congenital, Humans, Limb Deformities, Congenital, Male, Phenotype, Pierre Robin Syndrome, Urogenital Abnormalities}, issn = {1552-4833}, doi = {10.1002/ajmg.a.37735}, author = {Toriello, Helga V and Colley, Chelsey and Bamshad, Michael} } @article {213, title = {Dominant De Novo Mutations in GJA1 Cause Erythrokeratodermia Variabilis et Progressiva, without Features of Oculodentodigital Dysplasia.}, journal = {J Invest Dermatol}, volume = {135}, year = {2015}, month = {2015 Jun}, pages = {1540-1547}, abstract = {

Genetic investigation of inherited skin disorders has informed the understanding of skin self-renewal, differentiation, and barrier function. Erythrokeratodermia variabilis et progressiva (EKVP) is a rare, inherited skin disease that is characterized by transient figurate patches of erythema, localized or generalized scaling, and frequent palmoplantar keratoderma. By using exome sequencing, we show that de novo missense mutations in GJA1 (gap junction protein alpha 1) cause EKVP. The severe, progressive skin disease in EKVP subjects with GJA1 mutations is distinct from limited cutaneous findings rarely found in the systemic disorder oculodentodigital dysplasia, also caused by dominant GJA1 mutations. GJA1 encodes connexin 43 (Cx43), the most widely expressed gap junction protein. We show that the GJA1 mutations in EKVP subjects lead to disruption of Cx43 membrane localization and aggregation within the Golgi. These findings reveal a critical role for Cx43 in epidermal homeostasis, and they provide evidence of organ-specific pathobiology resulting from different mutations within GJA1.

}, keywords = {Amino Acid Sequence, Cell Membrane, Child, Child, Preschool, Connexin 43, Connexins, Craniofacial Abnormalities, Disease Progression, Erythrokeratodermia Variabilis, Exome, Eye Abnormalities, Female, Foot Deformities, Congenital, Golgi Apparatus, HeLa Cells, Humans, Immunohistochemistry, Male, Molecular Sequence Data, Mutagenesis, Site-Directed, Mutation, Phenotype, Sequence Analysis, DNA, Sequence Homology, Amino Acid, Skin Diseases, Syndactyly, Tooth Abnormalities}, issn = {1523-1747}, doi = {10.1038/jid.2014.485}, author = {Boyden, Lynn M and Craiglow, Brittany G and Zhou, Jing and Hu, Ronghua and Loring, Erin C and Morel, Kimberly D and Lauren, Christine T and Lifton, Richard P and Bilguvar, Kaya and Paller, Amy S and Choate, Keith A} } @article {183, title = {DVL1 frameshift mutations clustering in the penultimate exon cause autosomal-dominant Robinow syndrome.}, journal = {Am J Hum Genet}, volume = {96}, year = {2015}, month = {2015 Apr 02}, pages = {612-22}, abstract = {

Robinow syndrome is a genetically heterogeneous disorder characterized by mesomelic limb shortening, genital hypoplasia, and distinctive facial features and for which both autosomal-recessive and autosomal-dominant inheritance patterns have been described. Causative variants in the non-canonical signaling gene WNT5A underlie a subset of autosomal-dominant Robinow syndrome (DRS) cases, but most individuals with DRS remain without a molecular diagnosis. We performed whole-exome sequencing in four unrelated DRS-affected individuals without coding mutations in WNT5A and found heterozygous DVL1 exon 14 mutations in three of them. Targeted Sanger sequencing in additional subjects with DRS uncovered DVL1 exon 14 mutations in five individuals, including a pair of monozygotic twins. In total, six distinct frameshift mutations were found in eight subjects, and all were heterozygous truncating variants within the penultimate exon of DVL1. In five families in which samples from unaffected parents were available, the variants were demonstrated to represent de novo mutations. All variant alleles are predicted to result in a premature termination codon within the last exon, escape nonsense-mediated decay (NMD), and most likely generate a C-terminally truncated protein with a distinct -1 reading-frame terminus. Study of the transcripts extracted from affected subjects{\textquoteright} leukocytes confirmed expression of both wild-type and variant alleles, supporting the hypothesis that mutant mRNA escapes NMD. Genomic variants identified in our study suggest that truncation of the C-terminal domain of DVL1, a protein hypothesized to have a downstream role in the Wnt-5a non-canonical pathway, is a common cause of DRS.

}, keywords = {Adaptor Proteins, Signal Transducing, Amino Acid Sequence, Base Sequence, Craniofacial Abnormalities, Dishevelled Proteins, DNA Primers, Dwarfism, Exome, Exons, Frameshift Mutation, Gene Components, Humans, Limb Deformities, Congenital, Molecular Sequence Data, Phosphoproteins, Sequence Analysis, DNA, Urogenital Abnormalities}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.02.015}, author = {White, Janson and Mazzeu, Juliana F and Hoischen, Alexander and Jhangiani, Shalini N and Gambin, Tomasz and Alcino, Michele Calijorne and Penney, Samantha and Saraiva, Jorge M and Hove, Hanne and Skovby, Flemming and Kayserili, H{\"u}lya and Estrella, Elicia and Vulto-van Silfhout, Anneke T and Steehouwer, Marloes and Muzny, Donna M and Sutton, V Reid and Gibbs, Richard A and Lupski, James R and Brunner, Han G and van Bon, Bregje W M and Carvalho, Claudia M B} } @article {146, title = {GeneMatcher aids in the identification of a new malformation syndrome with intellectual disability, unique facial dysmorphisms, and skeletal and connective tissue abnormalities caused by de novo variants in HNRNPK.}, journal = {Hum Mutat}, volume = {36}, year = {2015}, month = {2015 Oct}, pages = {1009-1014}, abstract = {

We report a new syndrome due to loss-of-function variants in the heterogeneous nuclear ribonucleoprotein K gene (HNRNPK). We describe two probands: one with a de novo frameshift (NM_002140.3: c.953+1dup), and the other with a de novo splice donor site variant (NM_002140.3: c.257G>A). Both probands have intellectual disability, a shared unique craniofacial phenotype, and connective tissue and skeletal abnormalities. The identification of this syndrome was made possible by a new online tool, GeneMatcher, which facilitates connections between clinicians and researchers based on shared interest in candidate genes. This report demonstrates that new Web-based approaches can be effective in helping investigators solve exome sequencing projects, and also highlights the newer paradigm of "reverse phenotyping," where characterization of syndromic features follows the identification of genetic variants.

}, keywords = {Abnormalities, Multiple, Adolescent, Child, Craniofacial Abnormalities, Databases, Genetic, Genetic Predisposition to Disease, Heterogeneous-Nuclear Ribonucleoprotein K, Humans, Information Dissemination, Intellectual Disability, Male, Muscular Atrophy, Phenotype, Polymorphism, Single Nucleotide, Ribonucleoproteins, Software, Web Browser}, issn = {1098-1004}, doi = {10.1002/humu.22837}, author = {Au, P Y Billie and You, Jing and Caluseriu, Oana and Schwartzentruber, Jeremy and Majewski, Jacek and Bernier, Francois P and Ferguson, Marcia and Valle, David and Parboosingh, Jillian S and Sobreira, Nara and Innes, A Micheil and Kline, Antonie D} } @article {227, title = {Exome sequencing identifies a recurrent de novo ZSWIM6 mutation associated with acromelic frontonasal dysostosis.}, journal = {Am J Hum Genet}, volume = {95}, year = {2014}, month = {2014 Aug 07}, pages = {235-40}, abstract = {

Acromelic frontonasal dysostosis (AFND) is a rare disorder characterized by distinct craniofacial, brain, and limb malformations, including frontonasal dysplasia, interhemispheric lipoma, agenesis of the corpus callosum, tibial hemimelia, preaxial polydactyly of the feet, and intellectual disability. Exome sequencing of one trio and two unrelated probands revealed the same heterozygous variant (c.3487C>T [p. Arg1163Trp]) in a highly conserved protein domain of ZSWIM6; this variant has not been seen in the 1000 Genomes data, dbSNP, or the Exome Sequencing Project. Sanger validation of the three trios confirmed that the variant was de novo and was also present in a fourth isolated proband. In situ hybridization of early zebrafish embryos at 24 hr postfertilization (hpf) demonstrated telencephalic expression of zswim6 and onset of midbrain, hindbrain, and retinal expression at 48 hpf. Immunohistochemistry of later-stage mouse embryos demonstrated tissue-specific expression in the derivatives of all three germ layers. qRT-PCR expression analysis of osteoblast and fibroblast cell lines available from two probands was suggestive of Hedgehog pathway activation, indicating that the ZSWIM6 mutation associated with AFND may lead to the craniofacial, brain and limb malformations through the disruption of Hedgehog signaling.

}, keywords = {Abnormalities, Multiple, Amino Acid Sequence, Animals, Base Sequence, Craniofacial Abnormalities, DNA Mutational Analysis, DNA-Binding Proteins, Exome, Face, Hedgehog Proteins, Humans, Intellectual Disability, Limb Deformities, Congenital, Mandibulofacial Dysostosis, Mice, Molecular Sequence Data, Mutation, Protein Structure, Tertiary, Zebrafish, Zinc Fingers}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.07.008}, author = {Smith, Joshua D and Hing, Anne V and Clarke, Christine M and Johnson, Nathan M and Perez, Francisco A and Park, Sarah S and Horst, Jeremy A and Mecham, Brig and Maves, Lisa and Nickerson, Deborah A and Cunningham, Michael L} } @article {281, title = {The genetic basis of DOORS syndrome: an exome-sequencing study.}, journal = {Lancet Neurol}, volume = {13}, year = {2014}, month = {2014 Jan}, pages = {44-58}, abstract = {

BACKGROUND: Deafness, onychodystrophy, osteodystrophy, mental retardation, and seizures (DOORS) syndrome is a rare autosomal recessive disorder of unknown cause. We aimed to identify the genetic basis of this syndrome by sequencing most coding exons in affected individuals.

METHODS: Through a search of available case studies and communication with collaborators, we identified families that included at least one individual with at least three of the five main features of the DOORS syndrome: deafness, onychodystrophy, osteodystrophy, intellectual disability, and seizures. Participants were recruited from 26 centres in 17 countries. Families described in this study were enrolled between Dec 1, 2010, and March 1, 2013. Collaborating physicians enrolling participants obtained clinical information and DNA samples from the affected child and both parents if possible. We did whole-exome sequencing in affected individuals as they were enrolled, until we identified a candidate gene, and Sanger sequencing to confirm mutations. We did expression studies in human fibroblasts from one individual by real-time PCR and western blot analysis, and in mouse tissues by immunohistochemistry and real-time PCR.

FINDINGS: 26 families were included in the study. We did exome sequencing in the first 17 enrolled families; we screened for TBC1D24 by Sanger sequencing in subsequent families. We identified TBC1D24 mutations in 11 individuals from nine families (by exome sequencing in seven families, and Sanger sequencing in two families). 18 families had individuals with all five main features of DOORS syndrome, and TBC1D24 mutations were identified in half of these families. The seizure types in individuals with TBC1D24 mutations included generalised tonic-clonic, complex partial, focal clonic, and infantile spasms. Of the 18 individuals with DOORS syndrome from 17 families without TBC1D24 mutations, eight did not have seizures and three did not have deafness. In expression studies, some mutations abrogated TBC1D24 mRNA stability. We also detected Tbc1d24 expression in mouse phalangeal chondrocytes and calvaria, which suggests a role of TBC1D24 in skeletogenesis.

INTERPRETATION: Our findings suggest that mutations in TBC1D24 seem to be an important cause of DOORS syndrome and can cause diverse phenotypes. Thus, individuals with DOORS syndrome without deafness and seizures but with the other features should still be screened for TBC1D24 mutations. More information is needed to understand the cellular roles of TBC1D24 and identify the genes responsible for DOORS phenotypes in individuals who do not have a mutation in TBC1D24.

FUNDING: US National Institutes of Health, the CIHR (Canada), the NIHR (UK), the Wellcome Trust, the Henry Smith Charity, and Action Medical Research.

}, keywords = {Adolescent, Carrier Proteins, Child, Child, Preschool, Craniofacial Abnormalities, Exome, Female, Hand Deformities, Congenital, Hearing Loss, Sensorineural, Humans, Infant, Intellectual Disability, Internationality, Male, Nails, Malformed, Phenotype, Sequence Analysis, DNA, Young Adult}, issn = {1474-4465}, doi = {10.1016/S1474-4422(13)70265-5}, author = {Campeau, Philippe M and Kasperaviciute, Dalia and Lu, James T and Burrage, Lindsay C and Kim, Choel and Hori, Mutsuki and Powell, Berkley R and Stewart, Fiona and F{\'e}lix, T{\^e}mis Maria and van den Ende, Jenneke and Wisniewska, Marzena and Kayserili, H{\"u}lya and Rump, Patrick and Nampoothiri, Sheela and Aftimos, Salim and Mey, Antje and Nair, Lal D V and Begleiter, Michael L and De Bie, Isabelle and Meenakshi, Girish and Murray, Mitzi L and Repetto, Gabriela M and Golabi, Mahin and Blair, Edward and Male, Alison and Giuliano, Fabienne and Kariminejad, Ariana and Newman, William G and Bhaskar, Sanjeev S and Dickerson, Jonathan E and Kerr, Bronwyn and Banka, Siddharth and Giltay, Jacques C and Wieczorek, Dagmar and Tostevin, Anna and Wiszniewska, Joanna and Cheung, Sau Wai and Hennekam, Raoul C and Gibbs, Richard A and Lee, Brendan H and Sisodiya, Sanjay M} }