The ClinGen Syndromic Disorders Gene Curation Expert Panel: Assessing the Clinical Validity of 111 Gene-Disease Relationships
Broeren E, Gitau V, Byrne A, Ajuyah P, Balzotti M, Berg J, Bluske K, Bowen BM, Brown MP, Buchanan A, Burns B, Burns NJ, Chandrasekhar A, Chawla A, Chong J, Chopra M, Clause A, DiStefano M, DiTroia S, Elnagheeb M, Girod A, Goel H, Golden-Grant K, Ha T, Hamosh A, Huang J, Hughes M, Jamuar S, Kam S, Kesari A, Koh AL, Lassiter R, Leigh S, Lemire G, Lim JY, Malhotra A, McCurry H, Milewski B, Moosa S, Murray S, Owens E, Palmer E, Palus B, Patel M, Rajkumar R, Ratliff J, Raymond FL, Assis BDRR, Sajan S, Schlachetzki Z, Schmidt S, Stark Z, Strom S, Taylor J, Thaxton C, Thrush D, Toro S, Tshering K, Vasilevsky N, Wayburn B, Webb R, O’Donnell-Luria A, Coffey AJ. The ClinGen Syndromic Disorders Gene Curation Expert Panel: Assessing the Clinical Validity of 111 Gene-Disease Relationships. medRxiv [Preprint]. 2024 Nov 20:2024
medRxiv [Preprint]. 2024 Nov 20:2024.11.19.24317561. doi: 10.1101/2024.11.19.24317561.
ABSTRACT
PURPOSE: The Clinical Genome Resource (ClinGen) Gene Curation Expert Panels (GCEPs) have historically focused on specific organ systems or phenotypes; thus, the ClinGen Syndromic Disorders GCEP (SD-GCEP) was formed to address an unmet need.
METHODS: The SD-GCEP applied ClinGen’s framework to evaluate the clinical validity of genes associated with rare syndromic disorders. 111 Gene-Disease Relationships (GDRs) associated with 100 genes spanning the clinical spectrum of syndromic disorders were curated.
RESULTS: From April 2020 through March 2024, 38 precurations were performed on genes with multiple disease relationships and were reviewed to determine if the disorders were part of a spectrum or distinct entities. 14 genes were lumped into a single disease entity and 24 were split into separate entities, of which 11 were curated by the SD-GCEP. A full review of 111 GDRs for 100 genes followed, with 78 classified as Definitive, 9 as Strong, 15 as Moderate, and 9 as Limited highlighting where further data are needed. All diseases involved two or more organ systems, while the majority (88/111 GDRs, 79.2%) had five or more organ systems affected.
CONCLUSION: The SD-GCEP addresses a critical gap in gene curation efforts, enabling inclusion of genes for syndromic disorders in clinical testing and contributing to keeping pace with the rapid discovery of new genetic syndromes.
PMID:
39606380 | PMC:
PMC11601709 | DOI:
10.1101/2024.11.19.24317561
November 27, 2024
Neurogenomics
Consolidating the Role of Mutated ATP2B2 in Neurodevelopmental and Cerebellar Pathologies
Stehr AM, Lenberg J, Friedman J, Dobbelaere D, Imbard A, Levy J, Donoghue S, Derive N, Stoeva R, Gueguen P, Zech M. Consolidating the Role of Mutated ATP2B2 in Neurodevelopmental and Cerebellar Pathologies. Clin Genet. 2024
Clin Genet. 2024 Oct 5. doi: 10.1111/cge.14622. Online ahead of print.
ABSTRACT
Plasma membrane calcium ATPases (PMCAs) encoded by ATP2B genes have been implicated in Mendelian diseases with ataxia, dystonia, and intellectual disability. Work to date has shown that ATP2B2 (encoding PMCA2) is required for synaptic function and Purkinje-cell integrity in the cerebellum. A recent case series has linked ATP2B2 to a novel entity, characterized by neurodevelopmental and movement phenotypes, in only seven individuals. We called for collaboration to collect five unpublished families affected by the new rare ATP2B2-related condition. Exome-/genome sequencing-identified genotypes included four likely pathogenic/pathogenic heterozygous de novo missense variants and one dominantly inherited end-truncating frameshift allele. The six affected individuals shared features with the described patients including developmental delay, cognitive disturbances, epilepsy, autistic traits, and motor disorders. Striking cerebellar atrophy was observed in one affected individual. In association with hearing loss and movement abnormalities, we report a recurrent p.(Glu457Lys) substitution, previously documented in a neurologically impaired ATP2B2 mouse mutant. Our study further delineates the mutational spectrum and presentation of a human syndrome caused by ATP2B2 variants, confirming the importance of PMCA2 in neurotypical and cerebellar development.
PMID:
39367743 | DOI:
10.1111/cge.14622
November 20, 2024
Neurogenomics
Biallelic variants in ERLIN1: a series of 13 individuals with spastic paraparesis
Cogan G, Zaki MS, Issa M, Keren B, Guillaud-Bataille M, Renaldo F, Isapof A, Lallemant P, Stevanin G, Guillot-Noel L, Courtin T, Buratti J, Freihuber C, Gleeson JG, Howarth R, Durr A, de Sainte Agathe JM, Mignot C. Biallelic variants in ERLIN1: a series of 13 individuals with spastic paraparesis. Hum Genet. 2024 Nov;14
Abstract
Biallelic variants in the ERLIN1 gene were recently reported as the cause of two motor neuron degeneration diseases, SPG62 and a recessive form of amyotrophic lateral sclerosis. However, only 12 individuals from five pedigrees have been identified so far. Thus, the description of the disease remains limited. Following the discovery of a homozygous pathogenic variant in a girl with SPG62, presenting with intellectual disability, and epilepsy, we gathered the largest series of SPG62 cases reported so far (13 individuals) to better understand the phenotype associated with ERLIN1. We collected molecular and clinical data for 13 individuals from six families with ERLIN1 biallelic variants. We performed RNA-seq analyses to characterize intronic variants and used Alphafold and a transcripts database to characterize the molecular consequences of the variants. We identified three new variants suspected to alter the bell-shaped ring formed by the ERLIN1/ERLIN2 complex. Affected individuals had childhood-onset paraparesis with slow progression. Six individuals presented with gait ataxia and three had superficial sensory loss. Aside from our proband, none had intellectual disability or epilepsy. Biallelic pathogenic ERLIN1 variants induce a rare, predominantly pure, spastic paraparesis, with possible cerebellar and peripheral nerve involvement.
PMID: 39367212 | DOI: 10.1007/s00439-024-02702-0
November 14, 2024
Neurogenomics
The Face and Features of RNU4-2: A New, Common, Recognizable, Yet Hidden Neurodevelopmental Disorder
Barbour K, Bainbridge MN, Wigby K, Besterman AD, Chuang NA, Tobin LE, Del Campo M, Lenberg J, Bird LM, Friedman J. The Face and Features of RNU4-2: A New, Common, Recognizable, Yet Hidden Neurodevelopmental Disorder. Pediatr Neurol. 2024 Sep 21;161:188-193. doi: 10.1016/j.pediatrneurol.2024.09.015
Pediatr Neurol. 2024 Sep 21;161:188-193. doi: 10.1016/j.pediatrneurol.2024.09.015. Online ahead of print.
ABSTRACT
BACKGROUND: RNU4-2 is a newly identified, noncoding gene responsible for a significant proportion of individuals with neurodevelopmental disorders (NDDs). Diagnosis is hampered by the inability of commonly employed clinical testing methods, including exome sequencing and currently formulated multigene panels, to detect variants in the noncoding region. The relatively high prevalence of this condition, predicted to affect thousands of undiagnosed children with NDDs, makes it even more relevant to have better tools to facilitate diagnosis. The initial report of the gene-disease association outlined aggregate phenotypic features but lacked detailed patient evaluations, potentially under-reporting phenotypic features and failing to highlight unique aspects. We aimed to identify individuals with RNU4-2 gene variants to deeply phenotype the clinical profile. We sought to define key features that may suggest the diagnosis, to highlight individuals for whom specialized testing, able to detect noncoding region variants, may be indicated.
METHODS: We reviewed genomic data from 6,734 individuals, identifying five with recurrent de novo RNU4-2 (n.64_65insT) variants. We clinically evaluated four. Findings were compared with those previously reported.
RESULTS: We identify common clinical features, a distinctive dysmorphic facial pattern, and shared imaging abnormalities. We describe novel aspects including longitudinal trajectory and treatment response.
CONCLUSIONS: Enhanced recognition of the RNU4-2 (n.64_65insT-common variant) phenotype, particularly the dysmorphic facial features, will facilitate earlier diagnosis. Distinctive characteristics will guide the selection of patients for testing able to detect RNU4-2 variants: genome sequencing or targeted gene testing. Furthermore, health and research systems may identify undiagnosed patients by querying databases for individuals exhibiting the traits described herein.
PMID:
39423747 | DOI:
10.1016/j.pediatrneurol.2024.09.015
October 30, 2024
Neurogenomics
Autosomal recessive VWA1-related disorder: comprehensive analysis of phenotypic variability and genetic mutations
Nagy S, Pagnamenta AT, Cali E, Braakman HMH, Wijntjes J, Kusters B, Gotkine M, Elpeleg O, Meiner V, Lenberg J, Wigby K, Friedman J, Perry LD, Rossor AM, Uhrova Meszarosova A, Thomasova D, Jacob S, O’Driscoll M, De Simone L, Grange DK, Sommerville R, Firoozfar Z, Alavi S, Mazaheri M, Parmar JM, Lamont PJ, Pini V, Sarkozy A, Muntoni F, Ravenscroft G, Jones E, O’Rourke D, Nel M, Heckmann JM, Kvalsund M, Kapapa MM, Wa Somwe S, Bearden DR, Çakar A, Childs AM, Horvath R, Reilly MM, Houlden H, Maroofian R. Autosomal recessive VWA1-related disorder: comprehensive analysis of phenotypic variability and genetic mutations. Brain Commun. 2024 Oct 28
Brain Commun. 2024 Oct 28;6(6):fcae377. doi: 10.1093/braincomms/fcae377. eCollection 2024.
ABSTRACT
A newly identified subtype of hereditary axonal motor neuropathy, characterized by early proximal limb involvement, has been discovered in a cohort of 34 individuals with biallelic variants in von Willebrand factor A domain-containing 1 (VWA1). This study further delineates the disease characteristics in a cohort of 20 individuals diagnosed through genome or exome sequencing, incorporating neurophysiological, laboratory and imaging data, along with data from previously reported cases across three different studies. Newly reported clinical features include hypermobility/hyperlaxity, axial weakness, dysmorphic signs, asymmetric presentation, dystonic features and, notably, upper motor neuron signs. Foot drop, foot deformities and distal leg weakness followed by early proximal leg weakness are confirmed to be initial manifestations. Additionally, this study identified 11 novel VWA1 variants, reaffirming the 10 bp insertion-induced p.Gly25ArgfsTer74 as the most prevalent disease-causing allele, with a carrier frequency of ∼1 in 441 in the UK and Western European population. Importantly, VWA1-related pathology may mimic various neuromuscular conditions, advocating for its inclusion in diverse gene panels spanning hereditary neuropathies to muscular dystrophies. The study highlights the potential of lower quality control filters in exome analysis to enhance diagnostic yield of VWA1 disease that may account for up to 1% of unexplained hereditary neuropathies.
PMID:
39502942 | PMC:
PMC11535570 | DOI:
10.1093/braincomms/fcae377
October 28, 2024
Neurogenomics
Clinical factors associated with genetic diagnosis in suspected neurogenetic disorders in a tertiary care clinic
Wong NR, Klomhaus A, Adams DJ, Schneider BN, Mehta S, DiStefano C, Wilson RB, Martinez-Agosto JA, Jeste SS, Besterman AD. Clinical factors associated with genetic diagnosis in suspected neurogenetic disorders in a tertiary care clinic. Genet Med. 2024 Oct 10
Genet Med. 2024 Oct 10:101252. doi: 10.1016/j.gim.2024.101252. Online ahead of print.
ABSTRACT
PURPOSE: This study aimed to identify phenotypic factors associated with genetic diagnoses in patients with neurodevelopmental disorders and generate a decision tree to assist clinicians in identifying patients most likely to receive a positive result on genetic testing.
METHODS: We retrospectively reviewed the charts of 316 patients evaluated in a neurodevelopmental clinic between 2014 and 2019. Patients were categorized based on genetic test results. Analyses were performed to identify variables that discriminate between patients with and without a genetic diagnosis.
RESULTS: Patients with a genetic diagnosis were more likely to be female and have a history of motor delay, hypotonia, congenital heart disease, and early intervention. Classification and regression tree analysis revealed that 75% of patients with motor delay had a genetic diagnosis. In patients without motor delay, hypotonia, age of walking, and age at initial evaluation were important indicators of a genetic diagnosis.
CONCLUSION: Our findings suggest that motor delay and hypotonia are associated with genetic diagnoses in children with neurodevelopmental disorders. The decision tree highlights patient subsets at greater risk and suggests possible phenotypic screens. Future studies could develop validated decision trees based on phenotypic data to assist clinicians in stratifying patients for genetic testing.
PMID:
39395029 | DOI:
10.1016/j.gim.2024.101252
October 10, 2024
Genetic Neurologic DiseaseNeurogenomics
Elucidating the clinical and genetic spectrum of inositol polyphosphate phosphatase INPP4A-related neurodevelopmental disorder
Rawlins LE, Maroofian R, Cannon SJ, Daana M, Zamani M, Ghani S, Leslie JS, Ubeyratna N, Khan N, Khan H, Scardamaglia A, Cloarec R, Khan SA, Umair M, Sadeghian S, Galehdari H, Al-Maawali A, Al-Kindi A, Azizimalamiri R, Shariati G, Ahmad F, Al-Futaisi A, Rodriguez Cruz PM, Salazar-Villacorta A, Ndiaye M, Diop AG, Sedaghat A, Saberi A, Hamid M, Zaki MS, Vona B, Owrang D, Alhashem AM, Obeid M, Khan A, Beydoun A, Najjar M, Tajsharghi H, Zifarelli G, Bauer P, Hakami WS, Hashem AMA, Boustany RN, Burglen L, Alavi S, Gunning AC, Owens M, Karimiani EG, Gleeson JG, Milh M, Salah S, Khan J, Haucke V, Wright CF, McGavin L, Elpeleg O, Shabbir MI, Houlden H, Ebner M, Baple EL, Crosby AH. Elucidating the clinical and genetic spectrum of inositol polyphosphate phosphatase INPP4A-related neurodevelopmental disorder. Genet Med. 2024 Sep 20
Genet Med. 2024 Sep 20:101278. doi: 10.1016/j.gim.2024.101278. Online ahead of print.
ABSTRACT
PURPOSE: Biallelic INPP4A variants have recently been associated with severe neurodevelopmental disease in single case reports. Here, we expand and elucidate the clinical-genetic spectrum and provide a pathomechanistic explanation for genotype-phenotype correlations.
METHODS: Clinical and genomic investigations of 30 individuals were undertaken alongside molecular and in silico modelling and translation reinitiation studies.
RESULTS: We characterize a clinically variable disorder with cardinal features including global developmental delay, severe-profound intellectual disability, microcephaly, limb weakness, cerebellar signs and short stature. A more severe presentation associated with biallelic INPP4A variants downstream of exon 4 has additional features of (ponto)cerebellar hypoplasia, reduced cerebral volume, peripheral spasticity, contractures, intractable seizures and cortical visual impairment. Our studies identify the likely pathomechanism of this genotype-phenotype correlation entailing translational reinitiation in exon 4 resulting in an N-terminal truncated INPP4A protein retaining partial functionality, associated with less severe disease. We also identified identical reinitiation site conservation in Inpp4a-/- mouse models displaying similar genotype-phenotype correlation. Additionally, we show fibroblasts from a single affected individual exhibit disrupted endocytic trafficking pathways, indicating the potential biological basis of the condition.
CONCLUSION: Our studies comprehensively characterise INPP4A-related neurodevelopmental disorder and suggest genotype-specific clinical assessment guidelines. We propose the potential mechanistic basis of observed genotype-phenotype correlations entails exon 4 translation reinitiation.
PMID:
39315527 | DOI:
10.1016/j.gim.2024.101278
September 20, 2024
Neurogenomics
Loss of symmetric cell division of apical neural progenitors drives DENND5A-related developmental and epileptic encephalopathy
Banks E, Francis V, Lin SJ, Kharfallah F, Fonov V, Lévesque M, Han C, Kulasekaran G, Tuznik M, Bayati A, Al-Khater R, Alkuraya FS, Argyriou L, Babaei M, Bahlo M, Bakhshoodeh B, Barr E, Bartik L, Bassiony M, Bertrand M, Braun D, Buchert R, Budetta M, Cadieux-Dion M, Calame DG, Cope H, Cushing D, Efthymiou S, Elmaksoud MA, El Said HG, Froukh T, Gill HK, Gleeson JG, Gogoll L, Goh ES, Gowda VK, Haack TB, Hashem MO, Hauser S, Hoffman TL, Hogue JS, Hosokawa A, Houlden H, Huang K, Huynh S, Karimiani EG, Kaulfuß S, Korenke GC, Kritzer A, Lee H, Lupski JR, Marco EJ, McWalter K, Minassian A, Minassian BA, Murphy D, Neira-Fresneda J, Northrup H, Nyaga DM, Oehl-Jaschkowitz B, Osmond M, Person R, Pehlivan D, Petree C, Sadleir LG, Saunders C, Schoels L, Shashi V, Spillmann RC, Srinivasan VM, Torbati PN, Tos T; Undiagnosed Diseases Network; Zaki MS, Zhou D, Zweier C, Trempe JF, Durcan TM, Gan-Or Z, Avoli M, Alves C, Varshney GK, Maroofian R, Rudko DA, McPherson PS.
Nat Commun. 2024 Aug 22;15(1):7239. doi: 10.1038/s41467-024-51310-z.
ABSTRACT
Developmental and epileptic encephalopathies (DEEs) feature altered brain development, developmental delay and seizures, with seizures exacerbating developmental delay. Here we identify a cohort with biallelic variants in DENND5A, encoding a membrane trafficking protein, and develop animal models with phenotypes like the human syndrome. We demonstrate that DENND5A interacts with Pals1/MUPP1, components of the Crumbs apical polarity complex required for symmetrical division of neural progenitor cells. Human induced pluripotent stem cells lacking DENND5A fail to undergo symmetric cell division with an inherent propensity to differentiate into neurons. These phenotypes result from misalignment of the mitotic spindle in apical neural progenitors. Cells lacking DENND5A orient away from the proliferative apical domain surrounding the ventricles, biasing daughter cells towards a more fate-committed state, ultimately shortening the period of neurogenesis. This study provides a mechanism for DENND5A-related DEE that may be generalizable to other developmental conditions and provides variant-specific clinical information for physicians and families.
PMID:
39174524 | DOI:
10.1038/s41467-024-51310-z
August 22, 2024
Neurogenomics
Severe Acute Motor Exacerbations (SAME) across Metabolic, Developmental and Genetic Disorders
Couto B, Galosi S, Steel D, Kurian MA, Friedman J, Gorodetsky C, Lang AE.
Mov Disord. 2024 Aug 9. doi: 10.1002/mds.29905. Online ahead of print.
ABSTRACT
Acute presentation of severe motor disorders is a diagnostic and management challenge. We define severe acute motor exacerbations (SAME) as acute/subacute motor symptoms that persist for hours-to-days with a severity that compromise vital signs (temperature, breath, and heart rate) and bulbar function (swallowing/dysphagia). Phenomenology includes dystonia, choreoathetosis, combined movement disorders, weakness, and hemiplegic attacks. SAME can develop in diverse diseases and can be preceded by triggers or catabolic states. Recent descriptions of SAME in complex neurodevelopmental and epileptic encephalopathies have broadened appreciation of this presentation beyond inborn errors of metabolism. A high degree of clinical suspicion is required to identify appropriately targeted investigations and management. We conducted a comprehensive literature analysis of etiologies. Reported triggers are described and classified as per pathophysiological mechanism. A video of six cases displaying multiple SAME with diverse outcomes is provided. We identified 50 different conditions that manifest SAME, some associated with developmental regression. Etiologies include disorders of metabolism: energy substrate, amino acids, complex molecules, vitamins/cofactors, minerals, and neurotransmitters/synaptic vesicle cycling. Non-metabolic neurodegenerative and genetic disorders that present with movement disorders and epilepsy can additionally manifest SAME. A limited number of triggers are grouped here, together with an approach to investigations and general management strategies. Several neurogenetic and neurometabolic disorders manifest SAME. Identifying triggers can help in certain cases narrow the differential diagnosis and guide the expeditious application of targeted therapies to minimize adverse developmental and neurological consequences. This process may inform pathogenesis and eventually improve our understanding of the mechanisms that lead to the development of SAME. © 2024 International Parkinson and Movement Disorder Society.
PMID:
39119747 | DOI:
10.1002/mds.29905
August 9, 2024
Neurogenomics
Genome Sequencing for Diagnosing Rare Diseases
Wojcik MH, Lemire G, Berger E, Zaki MS, Wissmann M, Win W, White SM, Weisburd B, Wieczorek D, Waddell LB, Verboon JM, VanNoy GE, Töpf A, Tan TY, Syrbe S, Strehlow V, Straub V, Stenton SL, Snow H, Singer-Berk M, Silver J, Shril S, Seaby EG, Schneider R, Sankaran VG, Sanchis-Juan A, Russell KA, Reinson K, Ravenscroft G, Radtke M, Popp D, Polster T, Platzer K, Pierce EA, Place EM, Pajusalu S, Pais L, Õunap K, Osei-Owusu I, Opperman H, Okur V, Oja KT, O’Leary M, O’Heir E, Morel CF, Merkenschlager A, Marchant RG, Mangilog BE, Madden JA, MacArthur D, Lovgren A, Lerner-Ellis JP, Lin J, Laing N, Hildebrandt F, Hentschel J, Groopman E, Goodrich J, Gleeson JG, Ghaoui R, Genetti CA, Gburek-Augustat J, Gazda HT, Ganesh VS, Ganapathi M, Gallacher L, Fu JM, Evangelista E, England E, Donkervoort S, DiTroia S, Cooper ST, Chung WK, Christodoulou J, Chao KR, Cato LD, Bujakowska KM, Bryen SJ, Brand H, Bönnemann CG, Beggs AH, Baxter SM, Bartolomaeus T, Agrawal PB, Talkowski M, Austin-Tse C, Abou Jamra R, Rehm HL, O’Donnell-Luria A.
N Engl J Med. 2024 Jun 6;390(21):1985-1997. doi: 10.1056/NEJMoa2314761.
ABSTRACT
BACKGROUND: Genetic variants that cause rare disorders may remain elusive even after expansive testing, such as exome sequencing. The diagnostic yield of genome sequencing, particularly after a negative evaluation, remains poorly defined.
METHODS: We sequenced and analyzed the genomes of families with diverse phenotypes who were suspected to have a rare monogenic disease and for whom genetic testing had not revealed a diagnosis, as well as the genomes of a replication cohort at an independent clinical center.
RESULTS: We sequenced the genomes of 822 families (744 in the initial cohort and 78 in the replication cohort) and made a molecular diagnosis in 218 of 744 families (29.3%). Of the 218 families, 61 (28.0%) – 8.2% of families in the initial cohort – had variants that required genome sequencing for identification, including coding variants, intronic variants, small structural variants, copy-neutral inversions, complex rearrangements, and tandem repeat expansions. Most families in which a molecular diagnosis was made after previous nondiagnostic exome sequencing (63.5%) had variants that could be detected by reanalysis of the exome-sequence data (53.4%) or by additional analytic methods, such as copy-number variant calling, to exome-sequence data (10.8%). We obtained similar results in the replication cohort: in 33% of the families in which a molecular diagnosis was made, or 8% of the cohort, genome sequencing was required, which showed the applicability of these findings to both research and clinical environments.
CONCLUSIONS: The diagnostic yield of genome sequencing in a large, diverse research cohort and in a small clinical cohort of persons who had previously undergone genetic testing was approximately 8% and included several types of pathogenic variation that had not previously been detected by means of exome sequencing or other techniques. (Funded by the National Human Genome Research Institute and others.).
PMID:
38838312 | DOI:
10.1056/NEJMoa2314761
June 6, 2024
NeurogenomicsRare Disease
