@article {780, title = {De novo EIF2AK1 and EIF2AK2 Variants Are Associated with Developmental Delay, Leukoencephalopathy, and Neurologic Decompensation.}, journal = {Am J Hum Genet}, volume = {106}, year = {2020}, month = {2020 04 02}, pages = {570-583}, abstract = {

EIF2AK1 and EIF2AK2 encode members of the eukaryotic translation initiation factor 2 alpha kinase (EIF2AK) family that inhibits protein synthesis in response to physiologic stress conditions. EIF2AK2 is also involved in innate immune response and the regulation of signal transduction, apoptosis, cell proliferation, and differentiation. Despite these findings, human disorders associated with deleterious variants in EIF2AK1 and EIF2AK2 have not been reported. Here, we describe the identification of nine unrelated individuals with heterozygous de novo missense variants in EIF2AK1 (1/9) or EIF2AK2 (8/9). Features seen in these nine individuals include white matter alterations (9/9), developmental delay (9/9), impaired language (9/9), cognitive impairment (8/9), ataxia (6/9), dysarthria in probands with verbal ability (6/9), hypotonia (7/9), hypertonia (6/9), and involuntary movements (3/9). Individuals with EIF2AK2 variants also exhibit neurological regression in the setting of febrile illness or infection. We use mammalian cell lines and proband-derived fibroblasts to further confirm the pathogenicity of variants in these genes and found reduced kinase activity. EIF2AKs phosphorylate eukaryotic translation initiation factor 2 subunit 1 (EIF2S1, also known as EIF2α), which then inhibits EIF2B activity. Deleterious variants in genes encoding EIF2B proteins cause childhood ataxia with central nervous system hypomyelination/vanishing white matter (CACH/VWM), a leukodystrophy characterized by neurologic regression in the setting of febrile illness and other stressors. Our findings indicate that EIF2AK2 missense variants cause a neurodevelopmental syndrome that may share phenotypic and pathogenic mechanisms with CACH/VWM.

}, keywords = {Adolescent, Ataxia, Child, Child, Preschool, Developmental Disabilities, eIF-2 Kinase, Female, Genetic Variation, Hereditary Central Nervous System Demyelinating Diseases, Humans, Infant, Leukoencephalopathies, Male, Nervous System Malformations, White Matter}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2020.02.016}, author = {Mao, Dongxue and Reuter, Chloe M and Ruzhnikov, Maura R Z and Beck, Anita E and Farrow, Emily G and Emrick, Lisa T and Rosenfeld, Jill A and Mackenzie, Katherine M and Robak, Laurie and Wheeler, Matthew T and Burrage, Lindsay C and Jain, Mahim and Liu, Pengfei and Calame, Daniel and K{\"u}ry, S{\'e}bastien and Sillesen, Martin and Schmitz-Abe, Klaus and Tonduti, Davide and Spaccini, Luigina and Iascone, Maria and Genetti, Casie A and Koenig, Mary K and Graf, Madeline and Tran, Alyssa and Alejandro, Mercedes and Lee, Brendan H and Thiffault, Isabelle and Agrawal, Pankaj B and Bernstein, Jonathan A and Bellen, Hugo J and Chao, Hsiao-Tuan} } @article {810, title = {Missed diagnoses: Clinically relevant lessons learned through medical mysteries solved by the Undiagnosed Diseases Network.}, journal = {Mol Genet Genomic Med}, volume = {8}, year = {2020}, month = {2020 10}, pages = {e1397}, abstract = {

BACKGROUND: Resources within the Undiagnosed Diseases Network (UDN), such as genome sequencing (GS) and model organisms aid in diagnosis and identification of new disease genes, but are currently difficult to access by clinical providers. While these resources do contribute to diagnoses in many cases, they are not always necessary to reach diagnostic resolution. The UDN experience has been that participants can also receive diagnoses through the thoughtful and customized application of approaches and resources that are readily available in clinical settings.

METHODS: The UDN Genetic Counseling and Testing Working Group collected case vignettes that illustrated how clinically available methods resulted in diagnoses. The case vignettes were classified into three themes; phenotypic considerations, selection of genetic testing, and evaluating exome/GS variants and data.

RESULTS: We present 12 participants that illustrate how clinical practices such as phenotype-driven genomic investigations, consideration of variable expressivity, selecting the relevant tissue of interest for testing, utilizing updated testing platforms, and recognition of alternate transcript nomenclature resulted in diagnoses.

CONCLUSION: These examples demonstrate that when a diagnosis is elusive, an iterative patient-specific approach utilizing assessment options available to clinical providers may solve a portion of cases. However, this does require increased provider time commitment, a particular challenge in the current practice of genomics.

}, keywords = {Adolescent, Child, Child, Preschool, Databases, Factual, Diagnosis, Computer-Assisted, Female, Genetic Diseases, Inborn, Genetic Testing, Humans, Information Dissemination, Male, Middle Aged, Missed Diagnosis, National Institutes of Health (U.S.), Phenotype, Precision Medicine, Undiagnosed Diseases, United States, Young Adult}, issn = {2324-9269}, doi = {10.1002/mgg3.1397}, author = {Cope, Heidi and Spillmann, Rebecca and Rosenfeld, Jill A and Brokamp, Elly and Signer, Rebecca and Schoch, Kelly and Kelley, Emily G and Sullivan, Jennifer A and Macnamara, Ellen and Lincoln, Sharyn and Golden-Grant, Katie and Orengo, James P and Clark, Gary and Burrage, Lindsay C and Posey, Jennifer E and Punetha, Jaya and Robertson, Amy and Cogan, Joy and Phillips, John A and Martinez-Agosto, Julian and Shashi, Vandana} } @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 {353, title = {Corner fracture type spondylometaphyseal dysplasia: Overlap with type II collagenopathies.}, journal = {Am J Med Genet A}, volume = {173}, year = {2017}, month = {2017 Mar}, pages = {733-739}, abstract = {

Spondylometaphyseal dysplasia (SMD) corner fracture type (also known as SMD "Sutcliffe" type, MIM 184255) is a rare skeletal dysplasia that presents with mild to moderate short stature, developmental coxa vara, mild platyspondyly, corner fracture-like lesions, and metaphyseal abnormalities with sparing of the epiphyses. The molecular basis for this disorder has yet to be clarified. We describe two patients with SMD corner fracture type and heterozygous pathogenic variants in COL2A1. These two cases together with a third case of SMD corner fracture type with a heterozygous COL2A1 pathogenic variant previously described suggest that this disorder overlaps with type II collagenopathies. The finding of one of the pathogenic variants in a previously reported case of spondyloepimetaphyseal dysplasia (SEMD) Strudwick type and the significant clinical similarity suggest an overlap between SMD corner fracture and SEMD Strudwick types. {\textcopyright} 2016 Wiley Periodicals, Inc.

}, keywords = {Alleles, Amino Acid Substitution, Bone Diseases, Developmental, Child, Preschool, Collagen Type II, Diagnosis, Differential, Exome, Genetic Association Studies, Genotype, Growth Disorders, High-Throughput Nucleotide Sequencing, Hip Joint, Humans, Infant, Male, Mutation, Osteochondrodysplasias, Phenotype, Radiography, Tibial Fractures}, issn = {1552-4833}, doi = {10.1002/ajmg.a.38059}, author = {Machol, Keren and Jain, Mahim and Almannai, Mohammed and Orand, Thibault and Lu, James T and Tran, Alyssa and Chen, Yuqing and Schlesinger, Alan and Gibbs, Richard and Bonafe, Luisa and Campos-Xavier, Ana Belinda and Unger, Sheila and Superti-Furga, Andrea and Lee, Brendan H and Campeau, Philippe M and Burrage, Lindsay C} } @article {108, title = {De Novo GMNN Mutations Cause Autosomal-Dominant Primordial Dwarfism Associated with Meier-Gorlin Syndrome.}, journal = {Am J Hum Genet}, volume = {97}, year = {2015}, month = {2015 Dec 03}, pages = {904-13}, abstract = {

Meier-Gorlin syndrome (MGS) is a genetically heterogeneous primordial dwarfism syndrome known to be caused by biallelic loss-of-function mutations in one of five genes encoding pre-replication complex proteins: ORC1, ORC4, ORC6, CDT1, and CDC6. Mutations in these genes cause disruption of the origin of DNA replication initiation. To date, only an autosomal-recessive inheritance pattern has been described in individuals with this disorder, with a molecular etiology established in about three-fourths of cases. Here, we report three subjects with MGS and de novo heterozygous mutations in the 5{\textquoteright} end of GMNN, encoding the DNA replication inhibitor geminin. We identified two truncating mutations in exon 2 (the 1(st) coding exon), c.16A>T (p.Lys6(*)) and c.35_38delTCAA (p.Ile12Lysfs(*)4), and one missense mutation, c.50A>G (p.Lys17Arg), affecting the second-to-last nucleotide of exon 2 and possibly RNA splicing. Geminin is present during the S, G2, and M phases of the cell cycle and is degraded during the metaphase-anaphase transition by the anaphase-promoting complex (APC), which recognizes the destruction box sequence near the 5{\textquoteright} end of the geminin protein. All three GMNN mutations identified alter sites 5{\textquoteright} to residue Met28 of the protein, which is located within the destruction box. We present data supporting a gain-of-function mechanism, in which the GMNN mutations result in proteins lacking the destruction box and hence increased protein stability and prolonged inhibition of replication leading to autosomal-dominant MGS.

}, keywords = {Adolescent, Amino Acid Sequence, Base Sequence, Cell Cycle, Child, Preschool, Congenital Microtia, Dwarfism, Exons, Female, Geminin, Gene Expression, Genes, Dominant, Growth Disorders, Heterozygote, High-Throughput Nucleotide Sequencing, Humans, Inheritance Patterns, Male, Micrognathism, Molecular Sequence Data, Mutation, Patella, Pedigree, Protein Stability, Proteolysis, RNA Splicing, Sequence Alignment}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.11.006}, author = {Burrage, Lindsay C and Charng, Wu-Lin and Eldomery, Mohammad K and Willer, Jason R and Davis, Erica E and Lugtenberg, Dorien and Zhu, Wenmiao and Leduc, Magalie S and Akdemir, Zeynep C and Azamian, Mahshid and Zapata, Gladys and Hernandez, Patricia P and Schoots, Jeroen and de Munnik, Sonja A and Roepman, Ronald and Pearring, Jillian N and Jhangiani, Shalini and Katsanis, Nicholas and Vissers, Lisenka E L M and Brunner, Han G and Beaudet, Arthur L and Rosenfeld, Jill A and Muzny, Donna M and Gibbs, Richard A and Eng, Christine M and Xia, Fan and Lalani, Seema R and Lupski, James R and Bongers, Ernie M H F and Yang, Yaping} } @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} }