@article {575, title = {De Novo SOX4 Variants Cause a Neurodevelopmental Disease Associated with Mild Dysmorphism.}, journal = {Am J Hum Genet}, volume = {104}, year = {2019}, month = {2019 02 07}, pages = {246-259}, abstract = {

SOX4, together with SOX11 and SOX12, forms group C of SRY-related (SOX) transcription factors. They play key roles, often in redundancy, in multiple developmental pathways, including neurogenesis and skeletogenesis. De novo SOX11 heterozygous mutations have been shown to cause intellectual disability, growth deficiency, and dysmorphic features compatible with mild Coffin-Siris syndrome. Using trio-based exome sequencing, we here identify de novo SOX4 heterozygous missense variants in four children who share developmental delay, intellectual disability, and mild facial and digital morphological abnormalities. SOX4 is highly expressed in areas of active neurogenesis in human fetuses, and sox4 knockdown in Xenopus embryos diminishes brain and whole-body size. The SOX4 variants cluster in the highly conserved, SOX family-specific HMG domain, but each alters a different residue. In silico tools predict that each variant affects a distinct structural feature of this DNA-binding domain, and functional assays demonstrate that these SOX4 proteins carrying these variants are unable to bind DNA in~vitro and transactivate SOX reporter genes in cultured cells. These variants are not found in the gnomAD database of individuals with presumably normal development, but 12 other SOX4 HMG-domain missense variants~are recorded and all demonstrate partial to full activity in the reporter assay. Taken together, these findings point to specific SOX4 HMG-domain missense variants as the cause of a characteristic human neurodevelopmental disorder associated with mild facial and digital dysmorphism.

}, keywords = {Abnormalities, Multiple, Amino Acid Sequence, Animals, Child, Child, Preschool, Coffin-Lowry Syndrome, Cohort Studies, Conserved Sequence, DNA, Female, Heterozygote, HMG-Box Domains, Humans, Male, Mutation, Missense, Neurodevelopmental Disorders, SOXC Transcription Factors, Transcriptional Activation, Xenopus}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.12.014}, author = {Zawerton, Ash and Yao, Baojin and Yeager, J Paige and Pippucci, Tommaso and Haseeb, Abdul and Smith, Joshua D and Wischmann, Lisa and K{\"u}hl, Susanne J and Dean, John C S and Pilz, Daniela T and Holder, Susan E and McNeill, Alisdair and Graziano, Claudio and Lefebvre, V{\'e}ronique} } @article {21, title = {Recurrent De Novo and Biallelic Variation of ATAD3A, Encoding a Mitochondrial Membrane Protein, Results in Distinct Neurological Syndromes.}, journal = {Am J Hum Genet}, volume = {99}, year = {2016}, month = {2016 Oct 06}, pages = {831-845}, abstract = {

ATPase family AAA-domain containing protein 3A (ATAD3A) is a nuclear-encoded mitochondrial membrane protein implicated in mitochondrial dynamics, nucleoid organization, protein translation, cell growth, and cholesterol metabolism. We identified a recurrent de novo ATAD3A c.1582C>T (p.Arg528Trp) variant by whole-exome sequencing (WES) in five unrelated individuals with a core phenotype of global developmental delay, hypotonia, optic atrophy, axonal neuropathy, and hypertrophic cardiomyopathy. We also describe two families with biallelic variants in ATAD3A, including a homozygous variant in two siblings, and biallelic ATAD3A deletions mediated by nonallelic homologous recombination (NAHR) between ATAD3A and gene family members ATAD3B and ATAD3C. Tissue-specific overexpression of bor, the Drosophila mutation homologous to the human c.1582C>T (p.Arg528Trp) variant, resulted in a dramatic decrease in mitochondrial content, aberrant mitochondrial morphology, and increased autophagy. Homozygous null bor larvae showed a significant decrease of mitochondria, while overexpression of bor resulted in larger, elongated mitochondria. Finally, fibroblasts of an affected individual exhibited increased mitophagy. We conclude that the p.Arg528Trp variant functions through a dominant-negative mechanism that results in small mitochondria that trigger mitophagy, resulting in a reduction in mitochondrial content. ATAD3A variation represents an additional link between mitochondrial dynamics and recognizable neurological syndromes, as seen with MFN2, OPA1, DNM1L, and STAT2 mutations.

}, keywords = {Adenosine Triphosphatases, Adult, Alleles, Animals, ATPases Associated with Diverse Cellular Activities, Axons, Cardiomyopathies, Child, Child, Preschool, Developmental Disabilities, DNA Copy Number Variations, Drosophila melanogaster, Female, Fibroblasts, Homozygote, Humans, Infant, Infant, Newborn, Male, Membrane Proteins, Mitochondria, Mitochondrial Proteins, Muscle Hypotonia, Muscles, Mutation, Nervous System Diseases, Neurons, Optic Atrophy, Phenotype, Polymorphism, Single Nucleotide, Syndrome, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2016.08.007}, author = {Harel, Tamar and Yoon, Wan Hee and Garone, Caterina and Gu, Shen and Coban-Akdemir, Zeynep and Eldomery, Mohammad K and Posey, Jennifer E and Jhangiani, Shalini N and Rosenfeld, Jill A and Cho, Megan T and Fox, Stephanie and Withers, Marjorie and Brooks, Stephanie M and Chiang, Theodore and Duraine, Lita and Erdin, Serkan and Yuan, Bo and Shao, Yunru and Moussallem, Elie and Lamperti, Costanza and Donati, Maria A and Smith, Joshua D and McLaughlin, Heather M and Eng, Christine M and Walkiewicz, Magdalena and Xia, Fan and Pippucci, Tommaso and Magini, Pamela and Seri, Marco and Zeviani, Massimo and Hirano, Michio and Hunter, Jill V and Srour, Myriam and Zanigni, Stefano and Lewis, Richard Alan and Muzny, Donna M and Lotze, Timothy E and Boerwinkle, Eric and Gibbs, Richard A and Hickey, Scott E and Graham, Brett H and Yang, Yaping and Buhas, Daniela and Martin, Donna M and Potocki, Lorraine and Graziano, Claudio and Bellen, Hugo J and Lupski, James R} } @article {196, title = {Mutations in RAD21 disrupt regulation of APOB in patients with chronic intestinal pseudo-obstruction.}, journal = {Gastroenterology}, volume = {148}, year = {2015}, month = {2015 Apr}, pages = {771-782.e11}, abstract = {

BACKGROUND \& AIMS: Chronic intestinal pseudo-obstruction (CIPO) is characterized by severe intestinal dysmotility that mimics a mechanical subocclusion with no~evidence of gut obstruction. We searched for genetic variants associated with CIPO to increase our understanding of its pathogenesis and to identify potential biomarkers.

METHODS: We performed whole-exome sequencing of genomic DNA from patients with familial CIPO syndrome. Blood and lymphoblastoid cells were collected from patients and controls (individuals without CIPO); levels of messenger RNA (mRNA) and proteins were analyzed by quantitative reverse-transcription polymerase chain reaction, immunoblot, and mobility shift assays. Complementary DNAs were transfected into HEK293 cells. Expression of rad21 was suppressed in zebrafish embryos using a splice-blocking morpholino (rad21a). Gut tissues were collected and analyzed.

RESULTS: We identified a homozygous mutation (p.622, encodes Ala>Thr) in RAD21 in patients from a consanguineous family with CIPO. Expression of RUNX1, a target of RAD21, was reduced in cells from patients with CIPO compared with controls. In zebrafish, suppression of rad21a reduced expression of runx1; this phenotype was corrected by injection of human RAD21 mRNA, but not with the mRNA from the mutated p.622 allele. rad21a Morpholino zebrafish had delayed intestinal transit and greatly reduced numbers of enteric neurons, similar to patients with CIPO. This defect was greater in zebrafish with suppressed expression of ret and rad21, indicating their interaction in the regulation of gut neurogenesis. The promoter region of APOB bound RAD21 but not RAD21 p.622 Ala>Thr; expression of wild-type RAD21 in HEK293 cells repressed expression of APOB, compared with control vector. The gut-specific isoform of APOB (APOB48) is overexpressed in sera from patients with CIPO who carry the RAD21 mutation. APOB48 also is overexpressed in sporadic CIPO in sera and gut biopsy specimens.

CONCLUSIONS: Some patients with CIPO carry mutations in RAD21 that disrupt the ability of its product to regulate genes such as RUNX1 and APOB. Reduced expression of rad21 in zebrafish, and dysregulation of these target genes, disrupts intestinal transit and the development of enteric neurons.

}, keywords = {Adult, Animals, Apolipoprotein B-100, Case-Control Studies, Cell Cycle Proteins, Chronic Disease, Core Binding Factor Alpha 2 Subunit, Enteric Nervous System, Female, Gastrointestinal Motility, Gene Expression Profiling, Gene Knockdown Techniques, HEK293 Cells, Humans, Intestinal Pseudo-Obstruction, Male, Middle Aged, Nuclear Proteins, Phosphoproteins, RNA, Messenger, Sequence Analysis, DNA, Young Adult, Zebrafish, Zebrafish Proteins}, issn = {1528-0012}, doi = {10.1053/j.gastro.2014.12.034}, author = {Bonora, Elena and Bianco, Francesca and Cordeddu, Lina and Bamshad, Michael and Francescatto, Ludmila and Dowless, Dustin and Stanghellini, Vincenzo and Cogliandro, Rosanna F and Lindberg, Greger and Mungan, Zeynel and Cefle, Kivanc and Ozcelik, Tayfun and Palanduz, Sukru and Ozturk, Sukru and Gedikbasi, Asuman and Gori, Alessandra and Pippucci, Tommaso and Graziano, Claudio and Volta, Umberto and Caio, Giacomo and Barbara, Giovanni and D{\textquoteright}Amato, Mauro and Seri, Marco and Katsanis, Nicholas and Romeo, Giovanni and De Giorgio, Roberto} }