scholarly journals Neurodevelopmental disease genes implicated by de novo mutation and CNV morbidity

2017 ◽  
Author(s):  
Bradley P. Coe ◽  
Holly A.F. Stessman ◽  
Arvis Sulovari ◽  
Madeleine Geisheker ◽  
Fereydoun Hormozdiari ◽  
...  
Keyword(s):  
Developmental Delay ◽  
De Novo ◽  
Gene Dosage ◽  
De Novo Mutation ◽  
Disease Genes ◽  
Missense Mutations ◽  
Genomic Disorder ◽  
Network Analyses ◽  
Neurodevelopmental Disease ◽  
Deletion Syndromes

ABSTRACTWe combined de novo mutation (DNM) data from 10,927 cases of developmental delay and autism to identify 301 candidate neurodevelopmental disease genes showing an excess of missense and/or likely gene-disruptive (LGD) mutations. 164 genes were predicted by two different DNM models, including 116 genes with an excess of LGD mutations. Among the 301 genes, 76% show DNM in both autism and intellectual disability/developmental delay cohorts where they occur in 10.3% and 28.4% of the cases, respectively. Intersecting these results with copy number variation (CNV) morbidity data identifies a significant enrichment for the intersection of our gene set and genomic disorder regions (36/301, LR+ 2.53, p=0.0005). This analysis confirms many recurrent LGD genes and CNV deletion syndromes (e.g., KANSL1, PAFAH1B1, RA1, etc.), consistent with a model of haploinsufficiency. We also identify genes with an excess of missense DNMs overlapping deletion syndromes (e.g., KIF1A and the 2q37 deletion) as well as duplication syndromes, such as recurrent MAPK3 missense mutations within the chromosome 16p11.2 duplication, recurrent CHD4 missense DNMs in the 12p13 duplication region, and recurrent WDFY4 missense DNMs in the 10q11.23 duplication region. Finally, we also identify pathogenic CNVs overlapping more than one recurrently mutated gene (e.g., Sotos and Kleefstra syndromes) raising the possibility that multiple gene-dosage imbalances may contribute to phenotypic complexity of these disorders. Network analyses of genes showing an excess of DNMs confirm previous well-known enrichments but also highlight new functional networks, including cell-specific enrichments in the D1+ and D2+ spiny neurons of the striatum for both recurrently mutated genes and genes where missense mutations cluster.

scholarly journals Case Report: A Novel de novo Mutation in DNM1L Presenting With Developmental Delay, Ataxia, and Peripheral Neuropathy

2021 ◽  
Vol 9 ◽  
Author(s):  
Yanping Wei ◽  
Min Qian
Keyword(s):  
Peripheral Neuropathy ◽  
Developmental Delay ◽  
De Novo ◽  
Refractory Epilepsy ◽  
De Novo Mutation ◽  
Global Developmental Delay ◽  
Missense Mutations ◽  
Related Protein ◽  
Resonance Imaging ◽  
Genetic Results

DNM1L encodes dynamin-related protein 1 (Drp1), which is a member of the dynamin superfamily of GTPases and mediates mitochondrial and peroxisomal fission. In humans, several de novo heterozygous missense mutations in DNM1L have been reported, which were characterized by devastating courses with refractory epilepsy, myoclonus, and brain atrophy on MRI. We describe a 4.5-year-old male child harboring a novel de novo mutation in DNM1L presenting a phenotype of developmental delay, ataxia, and peripheral neuropathy. The clinical features, magnetic resonance imaging findings, and genetic results were summarized. Meanwhile, all the cases of DNM1L mutations reported were reviewed. DNM1L variants may need to be considered in phenotypes that include global developmental delay, peripheral neuropathy, and ataxia.

scholarly journals Neurodevelopmental disease genes implicated by de novo mutation and copy number variation morbidity

2018 ◽  
Vol 51 (1) ◽  
pp. 106-116 ◽  
Author(s):  
Bradley P. Coe ◽  
Holly A. F. Stessman ◽  
Arvis Sulovari ◽  
Madeleine R. Geisheker ◽  
Trygve E. Bakken ◽  
...  
Keyword(s):  
Copy Number Variation ◽  
Copy Number ◽  
De Novo ◽  
De Novo Mutation ◽  
Disease Genes ◽  
Neurodevelopmental Disease ◽  
Number Variation

Sleep Exacerbations and Facial Twitching: Diagnostic Clues for ADCY5-Related Dyskinesias

2020 ◽  
Author(s):  
Margherita Nosadini ◽  
Gianluca D'Onofrio ◽  
Maria Federica Pelizza ◽  
Concetta Luisi ◽  
Davide Padrin ◽  
...  
Keyword(s):  
Movement Disorder ◽  
Developmental Delay ◽  
De Novo ◽  
Brain Magnetic Resonance Imaging ◽  
Neurological Impairment ◽  
De Novo Mutation ◽  
Oligoclonal Bands ◽  
Emotional Stimuli ◽  
Childhood Onset ◽  
Ataxic Gait

Abstract Background Mutations in the adenylate cyclase 5 (ADCY5) gene are associated with childhood-onset paroxysmal dyskinesia. Methods We report a new video-documented case of pediatric ADCY5-related dyskinesia with de novo ADCY5 mutation. Results A boy born to nonconsanguineous parents after an uneventful pregnancy had developmental delay and hypotonia. At the age of 7 months, he presented with paroxysmal jerky–choreic–dystonic involuntary movements in wakefulness involving limbs, trunk, and face, exacerbated by emotional stimuli. These episodes gradually worsened in duration and frequency: at the age of 2.5 years, they occurred up to six times per day, and appeared also during sleep in prolonged bouts; the boy also had basal choreoathetoid–dystonic movements, hyperactivity, paraparetic–ataxic gait, generalized hypotonia with brisk tendon reflexes, drooling, and language delay with intellectual disability. Brain magnetic resonance imaging, electroencephalogram, electromyogram, eye review, metabolic investigations, oligoclonal bands, and autoantibodies were normal. Extensive genetic testing had not let to a diagnosis, until a heterozygous de novo mutation c.1252C > T (p.Arg418Trp) was identified in the ADCY5 gene. Clonazepam had partial effectiveness. The boy walked at the age of 3.5 years. At the age of 5 years, the paroxysmal movement disorder has slightly improved. Conclusion ADCY5 mutations should be considered among the differential diagnoses of early-onset paroxysmal choreic–athetosic–myoclonic–dystonic movement disorder involving limbs, trunk, and face, in patients with global neurological impairment with hypotonia and developmental delay. Facial dyskinesias and exacerbation by drowsiness/sleep and emotional stimuli are important clues that may allow a timely recognition of the disorder and avoidance of unnecessary diagnostic investigations.

A de novo mutation affecting human TrkB associated with severe obesity and developmental delay

2004 ◽  
Vol 7 (11) ◽  
pp. 1187-1189 ◽  
Author(s):  
Giles S H Yeo ◽  
Chiao-Chien Connie Hung ◽  
Justin Rochford ◽  
Julia Keogh ◽  
Juliette Gray ◽  
...  
Keyword(s):  
Developmental Delay ◽  
Severe Obesity ◽  
De Novo ◽  
De Novo Mutation

scholarly journals Identification of three candidate mutations causing type IIA von Willebrand disease using a rapid, nonradioactive, allele-specific hybridization method

Blood ◽  
1993 ◽  
Vol 82 (3) ◽  
pp. 830-836 ◽  
Author(s):  
A Inbal ◽  
T Englender ◽  
N Kornbrot ◽  
AM Randi ◽  
G Castaman ◽  
...  
Keyword(s):  
De Novo ◽  
Screening Method ◽  
Von Willebrand Disease ◽  
Rapid Screening ◽  
De Novo Mutation ◽  
Platelet Glycoprotein ◽  
Missense Mutations ◽  
Hybridization Method ◽  
Allele Specific ◽  
Von Willebrand

Type IIA von Willebrand disease (vWD), the most common type II vWD variant, is characterized by decreased binding of von Willebrand factor (vWF) to platelet glycoprotein Ib (Gplb) and by a decrease in large and intermediate vWF multimers. Mutations reported to cause vWD type IIA are clustered within the A2 domain of vWF, which is encoded by exon 28. Genomic DNA from affected members of 12 unrelated families with type IIA vWD were screened for these mutations by a rapid, nonradioactive, allele-specific oligonucleotide (ASO) hybridization method. Oligonucleotides containing each of eight mutations were cross-linked onto a nylon membrane by UV irradiation. A fragment of vWF exon 28 was amplified from peripheral blood leukocyte DNA using biotinylated primers and hybridized to the immobilized oligonucleotides. Positive signals were detected with an avidin-alkaline phosphatase conjugate and chemiluminescent substrate. Thus, in a single hybridization reaction, a patient sample could be analyzed for a large number of mutations simultaneously. Polymerase chain reaction (PCR) products from four patients did not contain any of the tested mutations and therefore were sequenced. Three additional candidate missense mutations, two of them novel, were identified: Arg(834)-->Gln in one patient, Gly(846)-->Arg in one patient, and Val(902)-->Glu in three ostensibly unrelated patients. By ASO hybridization, the mutations were confirmed in the affected patients and excluded in unaffected relatives and 50 normal controls. In one family, the Val(902)-->Glu mutation was shown to be a de novo mutation. This rapid screening method is applicable to other subtypes of vWD for which mutations have been identified.

scholarly journals Leukoencephalopathia, demyelinating peripheral neuropathy and dural ectasia explained by a not formerly described de novo mutation in the SAMD9L gene, ends 27 years of investigations – A case report

2019 ◽  
Author(s):  
Sofia Thunström ◽  
Markus Axelsson
Keyword(s):  
Case Report ◽  
Peripheral Neuropathy ◽  
De Novo ◽  
Age Of Onset ◽  
De Novo Mutation ◽  
Missense Mutations ◽  
Dural Ectasia ◽  
Whole Exome ◽  
Demyelinating Peripheral Neuropathy ◽  
Multiple Cysts

Abstract Background: Missense mutations in SAMD9L gene is associated with ataxia-pancytopenia syndrome (ATXPC), OMIM#159550. Common clinical features in these patients include neurological and hematological symptoms. The phenotype and age of onset is variable. Case Presentation: In this case report whole exome sequencing (WES) revealed a not previously reported de novo variant c.2686T>G, p.(Phe896Val) in SAMD9L in a patient with widespread findings of slow developing pathology in the peripheral and central nervous system. The clinical picture was dominated by neurological symptoms, unlike previously described cases, and in addition dural ectasias and multiple cysts in the brain was observed using magnetic resonance imaging. Conclusions: This case underscores the effect of variable expressivity, i.e. different mutations in the same gene can cause different phenotypes. Keywords: Leukoencephalopathia, demyelinating peripheral neuropathy, dural ectasia explained, de novo mutation, the SAMD9L gene.

scholarly journals Mapping Autosomal Recessive Intellectual Disability: Combined Microarray and Exome Sequencing Identifies 26 Novel Candidate Genes in 192 Consanguineous Families

2016 ◽  
Author(s):  
Ricardo Harripaul ◽  
Nasim Vasli ◽  
Anna Mikhailov ◽  
Muhammad Arshad Rafiq ◽  
Kirti Mittal ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Exome Sequencing ◽  
Autosomal Recessive ◽  
De Novo ◽  
Clinical Diagnostics ◽  
High Yield ◽  
Disease Genes ◽  
Missense Mutations ◽  
Loss Of Function ◽  
Whole Exome

Approximately 1% of the global population is affected by intellectual disability (ID), and the majority receive no molecular diagnosis. Previous studies have indicated high levels of genetic heterogeneity, with estimates of more than 2500 autosomal ID genes, the majority of which are autosomal recessive (AR). Here, we combined microarray genotyping, homozygosity-by-descent (HBD) mapping, copy number variation (CNV) analysis, and whole exome sequencing (WES) to identify disease genes/mutations in 192 multiplex Pakistani and Iranian consanguineous families with non-syndromic ID. We identified definite or candidate mutations (or CNVs) in 51% of families in 72 different genes, including 26 not previously reported for ARID. The new ARID genes include nine with loss-of-function mutations(ABI2, MAPK8, MPDZ, PIDD1, SLAIN1, TBC1D23, TRAPPC6B, UBA7,andUSP44),and missense mutations include the first reports of variants inBDNForTET1associated with ID. The genes identified also showed overlap withde novogene sets for other neuropsychiatric disorders. Transcriptional studies showed prominent expression in the prenatal brain. The high yield of AR mutations for ID indicated that this approach has excellent clinical potential and should inform clinical diagnostics, including clinical whole exome and genome sequencing, for populations in which consanguinity is common. As with other AR disorders, the relevance will also apply to outbred populations.

scholarly journals A Novel De Novo TUBB3 Variant Causing Developmental Delay, Epilepsy and Mild Ophthalmological Symptoms in a Chinese Child.

2021 ◽  
Author(s):  
Jiao Xue ◽  
Zhenfeng Song ◽  
Shuyin Ma ◽  
Zhi Yi ◽  
Chengqing Yang ◽  
...  
Keyword(s):  
Developmental Delay ◽  
De Novo ◽  
Febrile Seizures ◽  
Extraocular Muscles ◽  
Global Developmental Delay ◽  
Missense Mutations ◽  
Brain Malformations ◽  
Heterozygous Variant ◽  
Type 3 ◽  
Congenital Fibrosis

Abstract Heterozygous missense mutations in TUBB3 have been implicated in various neurological disorders encompassing either isolated congenital fibrosis of the extraocular muscles type 3 (CFEOM3) or complex cortical dysplasia with other brain malformations 1 (CDCBM1). The description of seizures in patients with TUBB3 mutations is rare. Here, we reported a patient who had febrile seizures before and focal seizure this time, which was diagnosed as epilepsy in combination with an abnormal EEG. MRI showed hypoplastic corpus callosum. Mutation analysis showed a novel de novo heterozygous variant of TUBB3 gene (NM_006086), c.763G>A (p.V255I). He had global developmental delay, photophobia and elliptic pupil, but lacking extraocular muscles involvement and malformations of cortical development, which might be a less severe phenotype of TUBB3 mutations. This was the first report of elliptic pupil in patients with TUBB3 mutations and expanded the spectrum of TUBB3 phenotypes. It indicated that the phenotypic range of TUBB3 mutations might be more continuous than discrete, with a severity ranging from mild to severe. Further studies are needed to elucidate the complete spectrum of TUBB3-related phenotypes.

scholarly journals De novo Mutations in NALCN Cause a Syndrome of Congenital Contractures of the Limbs and Face with Hypotonia, and Developmental Delay

2015 ◽  
Author(s):  
Jessica X Chong ◽  
Margaret J McMillin ◽  
Kathryn M Shively ◽  
Anita E Beck ◽  
Colby T Marvin ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Developmental Delay ◽  
De Novo ◽  
Dominant Negative ◽  
Protein Domain ◽  
Dominant Negative Effect ◽  
Global Developmental Delay ◽  
Missense Mutations ◽  
Severe Intellectual Disability ◽  
Dominant Condition

Freeman-Sheldon syndrome, or distal arthrogryposis type 2A (DA2A), is an autosomal dominant condition caused by mutations in MYH3 and characterized by multiple congenital contractures of the face and limbs and normal cognitive development. We identified a subset of five simplex cases putatively diagnosed with “DA2A with severe neurological abnormalities” in which the proband had Congenital Contractures of the LImbs and FAce, Hypotonia, and global Developmental Delay often resulting in early death, a unique condition that we now refer to as CLIFAHDD syndrome. Exome sequencing identified missense mutations in sodium leak channel, nonselective (NALCN) in four families with CLIFAHDD syndrome. Using molecular inversion probes to screen NALCN in a cohort of 202 DA cases as well as concurrent exome sequencing of six other DA cases revealed NALCN mutations in ten additional families with “atypical” forms of DA. All fourteen mutations were missense variants predicted to alter amino acid residues in or near the S5 and S6 pore-forming segments of NALCN, highlighting the functional importance of these segments. In vitro functional studies demonstrated that mutant NALCN nearly abolished the expression of wildtype NALCN, suggesting that mutations that cause CLIFAHDD syndrome have a dominant negative effect. In contrast, homozygosity for mutations in other regions of NALCN has been reported in three families with an autosomal recessive condition characterized mainly by hypotonia and severe intellectual disability. Accordingly, mutations in NALCN can cause either a recessive or dominant condition with varied though overlapping phenotypic features perhaps depending on the type of mutation and affected protein domain(s).

Sign in / Sign up

Export Citation Format

Share Document