scholarly journals Shukla-Vernon Syndrome: A Second Family with a Novel Variant in the BCORL1 Gene

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 452
Author(s):  
Babylakshmi Muthusamy ◽  
Anikha Bellad ◽  
Satish Chandra Girimaji ◽  
Akhilesh Pandey
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
Protein Complexes ◽  
Neurodevelopmental Disorder ◽  
Missense Variant ◽  
Global Developmental Delay ◽  
Dysmorphic Features ◽  
Pathogenic Variants ◽  
Behavioral Abnormalities ◽  
Novel Variant

Shukla-Vernon syndrome (SHUVER) is an extremely rare neurodevelopmental disorder characterized by global developmental delay, intellectual disability, behavioral anomalies, and dysmorphic features. Pathogenic variants in the BCORL1 gene have been identified as the molecular cause for this disorder. The BCORL1 gene encodes for BCL-6 corepressor-like protein 1, a transcriptional corepressor that is an integral component of protein complexes involved in transcription repression. In this study, we report an Indian family with two male siblings with features of Shukla-Vernon syndrome. The patients exhibited global developmental delay, intellectual disability, kyphosis, seizures, and dysmorphic features including bushy prominent eyebrows with synophrys, sharp beaked prominent nose, protuberant lower jaw, squint, and hypoplastic ears with fused ear lobes. No behavioral abnormalities were observed. Whole exome sequencing revealed a novel potentially pathogenic arginine to cysteine substitution (p.Arg1265Cys) in the BCORL1 protein. This is the second report of Shukla-Vernon syndrome with a novel missense variant in the BCORL1 gene. Our study confirms and expands the phenotypes and genotypes described previously for this syndrome and should aid in diagnosis and genetic counselling of patients and their families.

scholarly journals Clinical characteristics of Polish patients with molecularly confirmed Mowat-Wilson syndrome

2021 ◽  
Author(s):  
Aleksandra Jakubiak ◽  
Krzysztof Szczałuba ◽  
Magdalena Badura-Stronka ◽  
Anna Kutkowska-Kaźmierczak ◽  
Anna Jakubiuk-Tomaszuk ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Congenital Anomalies ◽  
Chromosomal Region ◽  
Neurodevelopmental Disorder ◽  
Hirschsprung Disease ◽  
Psychomotor Retardation ◽  
Facial Features ◽  
Dysmorphic Features ◽  
Pathogenic Variants ◽  
Intragenic Deletions

AbstractMowat-Wilson syndrome is a rare neurodevelopmental disorder caused by pathogenic variants in the ZEB2 gene, intragenic deletions of the ZEB2 gene, and microdeletions in the critical chromosomal region 2q22-23, where the ZEB2 gene is located. Mowat-Wilson syndrome is characterized by typical facial features that change with the age, severe developmental delay with intellectual disability, and multiple congenital abnormalities. The authors describe the clinical and genetic aspects of 28th patients with Mowat-Wilson syndrome diagnosed in Poland. Characteristic dysmorphic features, psychomotor retardation, intellectual disability, and congenital anomalies were present in all cases. The incidence of most common congenital anomalies (heart defect, Hirschsprung disease, brain defects) was similar to presented in literature. Epilepsy was less common compared to previously reported cases. Although the spectrum of disorders in patients with Mowat-Wilson syndrome is wide, knowledge of characteristic dysmorphic features awareness of accompanying abnormalities, especially intellectual disability, improves detection of the syndrome.

scholarly journals OTUD5 Variants Associated With X-Linked Intellectual Disability and Congenital Malformation

2021 ◽  
Vol 9 ◽  
Author(s):  
Ken Saida ◽  
Tokiko Fukuda ◽  
Daryl A. Scott ◽  
Toru Sengoku ◽  
Kazuhiro Ogata ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
Ovarian Tumor ◽  
Brain Magnetic Resonance Imaging ◽  
Missense Variant ◽  
The Novel ◽  
Nasal Bridge ◽  
Congenital Cardiac Anomalies ◽  
Novel Variant ◽  
Long Term Prognosis

BackgroundX-linked intellectual disability (XLID), which occurs predominantly in males, is a relatively common and genetically heterogeneous disorder in which over 100 mutated genes have been reported. The OTUD5 gene at Xp11.23 encodes ovarian tumor deubiquitinase 5 protein, which is a deubiquitinating enzyme member of the ovarian tumor family. LINKage-specific-deubiquitylation-deficiency-induced embryonic defects (LINKED) syndrome, arising from pathogenic OTUD5 variants, was recently reported as a new XLID with additional congenital anomalies.MethodsWe investigated three affected males (49- and 47-year-old brothers [Individuals 1 and 2] and a 2-year-old boy [Individual 3]) from two families who showed developmental delay. Their common clinical features included developmental delay, hypotonia, short stature, and distinctive facial features, such as telecanthus and a depressed nasal bridge. Individuals 1 and 2 showed epilepsy and brain magnetic resonance imaging showed a thin corpus callosum and mild ventriculomegaly. Individual 3 showed congenital malformations, including tetralogy of Fallot, hypospadias, and bilateral cryptorchidism. To identify the genetic cause of these features, we performed whole-exome sequencing.ResultsA hemizygous OTUD5 missense variant, c.878A>T, p.Asn293Ile [NM_017602.4], was identified in one family with Individuals 1 and 2, and another missense variant, c.1210 C>T, p.Arg404Trp, in the other family with Individual 3, respectively. The former variant has not been registered in public databases and was predicted to be pathogenic by multiple in silico prediction tools. The latter variant p.Arg404Trp was previously reported as a pathogenic OTUD5 variant, and Individual 3 showed a typical LINKED syndrome phenotype. However, Individuals 1 and 2, with the novel variant (p.Asn293Ile), showed no cardiac or genitourinary malformations.ConclusionsUnlike previous reports of LINKED syndrome, which described early lethality with congenital cardiac anomalies, our three cases are still alive. Notably, the adult brothers with the novel missense OTUD5 variant have lived into their forties. This may be indicative of a milder phenotype as a possible genotype-phenotype correlation. These findings imply a possible long-term prognosis for individuals with this new XLID syndrome, and a wider phenotypic variation than initially thought.

scholarly journals X-linked neonatal-onset epileptic encephalopathy associated with a gain-of-function variant p.R660T in GRIA3

PLoS Genetics ◽  
2021 ◽  
Vol 17 (6) ◽  
pp. e1009608
Author(s):  
Jia-Hui Sun ◽  
Jiang Chen ◽  
Fernando Eduardo Ayala Valenzuela ◽  
Carolyn Brown ◽  
Diane Masser-Frye ◽  
...  
Keyword(s):  
Developmental Delay ◽  
Prolonged Exposure ◽  
De Novo ◽  
Missense Variant ◽  
Epileptic Encephalopathy ◽  
Global Developmental Delay ◽  
Decay Kinetics ◽  
Gain Of Function ◽  
Ca1 Neurons ◽  
Pathogenic Variants

The X-linked GRIA3 gene encodes the GLUA3 subunit of AMPA-type glutamate receptors. Pathogenic variants in this gene were previously reported in neurodevelopmental diseases, mostly in male patients but rarely in females. Here we report a de novo pathogenic missense variant in GRIA3 (c.1979G>C; p. R660T) identified in a 1-year-old female patient with severe epilepsy and global developmental delay. When exogenously expressed in human embryonic kidney (HEK) cells, GLUA3_R660T showed slower desensitization and deactivation kinetics compared to wildtype (wt) GLUA3 receptors. Substantial non-desensitized currents were observed with the mutant but not for wt GLUA3 with prolonged exposure to glutamate. When co-expressed with GLUA2, the decay kinetics were similarly slowed in GLUA2/A3_R660T with non-desensitized steady state currents. In cultured cerebellar granule neurons, miniature excitatory postsynaptic currents (mEPSCs) were significantly slower in R660T transfected cells than those expressing wt GLUA3. When overexpressed in hippocampal CA1 neurons by in utero electroporation, the evoked EPSCs and mEPSCs were slower in neurons expressing R660T mutant compared to those expressing wt GLUA3. Therefore our study provides functional evidence that a gain of function (GoF) variant in GRIA3 may cause epileptic encephalopathy and global developmental delay in a female subject by enhancing synaptic transmission.

scholarly journals Expanding the Phenotype of TUBB2A-Related Tubulinopathy: Three Cases of a Novel, Heterozygous TUBB2A Pathogenic Variant p.Gly98Arg

2020 ◽  
pp. 1-8
Author(s):  
Lindsey Schmidt ◽  
Karen E. Wain ◽  
Catherine Hajek ◽  
Juvianee I. Estrada-Veras ◽  
Maria J. Guillen Sacoto ◽  
...  
Keyword(s):  
Developmental Delay ◽  
Case Series ◽  
Missense Variant ◽  
Autism Spectrum ◽  
Cortical Dysplasia ◽  
Global Developmental Delay ◽  
Tubulin Genes ◽  
Pathogenic Variants ◽  
Brain Malformations ◽  
History Of

Tubulinopathies are a group of conditions caused by variants in 6 tubulin genes that present with a spectrum of brain malformations. One of these conditions is <i>TUBB2A</i>-related tubulinopathy. Currently, there are 9 reported individuals with pathogenic variants within the <i>TUBB2A</i> gene, with common manifestations including, but not limited to, global developmental delay, seizures, cortical dysplasia, and dysmorphic corpus callosum. We report 3 patients identified by exome and genome sequencing to have a novel, pathogenic, missense variant in <i>TUBB2A</i> (p.Gly98Arg). They presented similarly with intellectual disability, hypotonia, and global developmental delay and varied with respect to the type of cortical brain malformation, seizure history, diagnosis of autism spectrum disorder, and other features. This case series expands the natural history of <i>TUBB2A</i>-related tubulinopathy while describing the presentation of a novel, pathogenic, missense variant in 3 patients.

scholarly journals Delineating the molecular and phenotypic spectrum of the SETD1B-related syndrome

2021 ◽  
Author(s):  
Marjolein J. A. Weerts ◽  
Kristina Lanko ◽  
Francisco J. Guzmán-Vega ◽  
Adam Jackson ◽  
Reshmi Ramakrishnan ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
Neurodevelopmental Disorder ◽  
Epileptic Activity ◽  
Language Delay ◽  
Global Developmental Delay ◽  
Sequence Variants ◽  
Loss Of Function ◽  
Phenotypic Spectrum

Abstract Purpose Pathogenic variants in SETD1B have been associated with a syndromic neurodevelopmental disorder including intellectual disability, language delay, and seizures. To date, clinical features have been described for 11 patients with (likely) pathogenic SETD1B sequence variants. This study aims to further delineate the spectrum of the SETD1B-related syndrome based on characterizing an expanded patient cohort. Methods We perform an in-depth clinical characterization of a cohort of 36 unpublished individuals with SETD1B sequence variants, describing their molecular and phenotypic spectrum. Selected variants were functionally tested using in vitro and genome-wide methylation assays. Results Our data present evidence for a loss-of-function mechanism of SETD1B variants, resulting in a core clinical phenotype of global developmental delay, language delay including regression, intellectual disability, autism and other behavioral issues, and variable epilepsy phenotypes. Developmental delay appeared to precede seizure onset, suggesting SETD1B dysfunction impacts physiological neurodevelopment even in the absence of epileptic activity. Males are significantly overrepresented and more severely affected, and we speculate that sex-linked traits could affect susceptibility to penetrance and the clinical spectrum of SETD1B variants. Conclusion Insights from this extensive cohort will facilitate the counseling regarding the molecular and phenotypic landscape of newly diagnosed patients with the SETD1B-related syndrome.

scholarly journals Clinical and Genetic Characteristics and Prenatal Diagnosis of Rare Monogenic Global Developmental Delay and Intellectual Disability.

2020 ◽  
Author(s):  
Liling Lin ◽  
Ying Zhang ◽  
Hong Pan ◽  
Jingmin Wang ◽  
Yu Qi ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Prenatal Diagnosis ◽  
Developmental Delay ◽  
Hot Spot ◽  
Disease Onset ◽  
Genetic Diagnosis ◽  
Global Developmental Delay ◽  
Genetic Characteristics ◽  
Pathogenic Variants

Abstract Background: The estimated worldwide prevalence of global developmental delay (GDD) and intellectual disability (ID) is 1-3%. Rare monogenic GDD/ID is poorly characterized because its low prevalence limits research. In this study, we aimed to describe the diagnostic courses and clinical and genetic characteristics of a cohort with rare monogenic GDD/ID.Method:We retrospectively analyzed the diagnostic courses, clinical characteristics, and genetic spectra of rare monogenic GDD/ID patients. We also conducted a follow-up study on prenatal diagnosis in these families. Mutation pathogenicity was interpreted by molecular geneticists and clinicians according to the guidelines of the American College of Medical Genetics and Genomics. Results:Among 108 patients with rare monogenic GDD/ID, it often took 0.5-4 years and 3-5 referrals to obtain a genetic diagnosis after disease onset. Onset typically occurred before 6 years of age, and patients usually presented moderate to severe GDD/ID. The most common coexisting conditions were epilepsy (68%), facial dysmorphism (14%) and microcephaly (13%). In total, 149 different pathogenic variants were found in 81 different genes among the 108 pedigrees, and 71 variants were novel. The most common inheritance patterns in this outbred Chinese population were autosomal recessive (AR; 46.3%), autosomal dominant (AD; 37%), and X-linked (XL; 16.7%). GLB1, PLA2G6, SCN2A, SHANK3 and STXBP1 were important causal genes. Hot-spot mutations were rarely found. By the follow-up, 43 families, including 24 ARID, 13 ADID and 6 XLID families, had undergone prenatal diagnosis. The offspring of 6 ARID, 2 ADID and 2 XLID families had the same pathogenic variants as the probands.Conclusion:Rare monogenic GDD/ID is characterized by early onset, relatively severe symptoms, great clinical variability and genetic heterogeneity. Moreover, timely referrals to genetic counseling and prenatal diagnostic laboratories are important for affected families planning to have additional children.

scholarly journals Delineating the molecular and phenotypic spectrum of the SETD1B-related syndrome

2021 ◽  
Author(s):  
Marjolein J.A. Weerts ◽  
Kristina Lanko ◽  
Francisco J. Guzmán-Vega ◽  
Adam Jackson ◽  
Reshmi Ramakrishnan ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
Neurodevelopmental Disorder ◽  
Epileptic Activity ◽  
Language Delay ◽  
Global Developmental Delay ◽  
Sequence Variants ◽  
Loss Of Function ◽  
Phenotypic Spectrum

ABSTRACTPathogenic variants in SETD1B have been associated with a syndromic neurodevelopmental disorder including intellectual disability, language delay and seizures. To date, clinical features have been described for eleven patients with (likely) pathogenic SETD1B sequence variants. We perform an in-depth clinical characterization of a cohort of 36 unpublished individuals with SETD1B sequence variants, describing their molecular and phenotypic spectrum. Selected variants were functionally tested using in vitro and genome-wide methylation assays. Our data present evidence for a loss-of-function mechanism of SETD1B variants, resulting in a core clinical phenotype of global developmental delay, language delay including regression, intellectual disability, autism and other behavioral issues, and variable epilepsy phenotypes. Developmental delay appeared to precede seizure onset, suggesting SETD1B dysfunction impacts physiological neurodevelopment even in the absence of epileptic activity. Interestingly, males are significantly overrepresented and more severely affected, and we speculate that sex-linked traits could affect susceptibility to penetrance and the clinical spectrum of SETD1B variants. Finally, despite the possibility of non-redundant contributions of SETD1B and its paralogue SETD1A to epigenetic control, the clinical phenotypes of the related disorders share many similarities, indicating that elucidating shared and divergent downstream targets of both genes will help to understand the mechanism leading to the neurobehavioral phenotypes. Insights from this extensive cohort will facilitate the counseling regarding the molecular and phenotypic landscape of newly diagnosed patients with the SETD1B-related syndrome.

scholarly journals Homozygous missense WIPI2 variants cause a congenital disorder of autophagy with neurodevelopmental impairments of variable clinical severity and disease course

2021 ◽  
Author(s):  
Reza Maroofian ◽  
Andrea Gubas ◽  
Rauan Kaiyrzhanov ◽  
Marcello Scala ◽  
Khalid Hundallah ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Neurodevelopmental Disorder ◽  
Missense Variant ◽  
Clinical Severity ◽  
Global Developmental Delay ◽  
Disease Course ◽  
Single Family ◽  
Ataxic Gait ◽  
Related Disorder ◽  
Autophagy Pathway

Abstract WIPI2 is a member of the human WIPI protein family (seven-bladed b-propeller proteins binding phosphatidylinositols, PROPPINs), which play a pivotal role in autophagy and has been implicated in the pathogenesis of several neurological conditions. The homozygous WIPI2 variant c.745G&gt;A; p.(Val249Met) (NM_015610.4) has recently been associated with a neurodevelopmental disorder in a single family. Using exome sequencing and Sanger segregation analysis, here two novel homozygous WIPI2 variants (c.551T&gt;G; p.(Val184Gly) and c.724C&gt;T; p.(Arg242Trp) (NM_015610.4)) were identified in four individuals of two consanguineous families. Additionally, follow-up clinical data were sought from the previously reported family. Three non-ambulant affected siblings of the first family harboring the p.(Val184Gly) missense variant presented with microcephaly, profound global developmental delay/intellectual disability, refractory infantile/childhood-onset epilepsy, progressive tetraplegia with joint contractures, and dyskinesia. In contrast, the proband of the second family carrying the p.(Arg242Trp) missense variant, similar to the initially reported WIPI2 cases, presented with a milder phenotype, encompassing moderate intellectual disability, speech and visual impairment, autistic features, and an ataxic gait. Brain MR imaging in five patients showed prominent white matter involvement with a global reduction in volume, posterior corpus callosum hypoplasia, abnormal dentate nuclei, and hypoplasia of the inferior cerebellar vermis. To investigate the functional impact of these novel WIPI2 variants, we overexpressed both in WIPI2-knockout HEK293A cells. In comparison to wildtype, expression of the Val166Gly WIPI2b mutant resulted in a deficient rescue of LC3 lipidation whereas Arg224Trp mutant increased LC3 lipidation, in line with the previously reported Val231Met variant. These findings support a dysregulation of the early steps of the autophagy pathway. Collectively, our findings provide evidence that biallelic WIPI2 variants cause a neurodevelopmental disorder of variable severity and disease course. Our report expands the clinical spectrum and establishes WIPI2-related disorder as a congenital disorders of autophagy.

scholarly journals A novel de novo KDM5C variant in a female with global developmental delay and ataxia: a case report

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Natalie C. Lippa ◽  
Subit Barua ◽  
Vimla Aggarwal ◽  
Elaine Pereira ◽  
Jennifer M. Bain
Keyword(s):  
Case Report ◽  
Intellectual Disability ◽  
Short Stature ◽  
Developmental Delay ◽  
De Novo ◽  
Phenotypic Variability ◽  
Missense Variant ◽  
Global Developmental Delay ◽  
Related Disorder ◽  
Patient Reported

Abstract Background Pathogenic variants in KDM5C are a cause of X-linked intellectual disability in males. Other features in males include short stature, dysmorphic features, seizures and spasticity. In some instances, female relatives were noted to have learning difficulties and mild intellectual disabilities, but full phenotypic descriptions were often incomplete. Recently, detailed phenotypic features of five affected females with de novo variants were described. (Clin Genet 98:43–55, 2020) Four individuals had a protein truncating variant and 1 individual had a missense variant. All five individuals had developmental delay/intellectual disability and three neurological features. Case presentation Here we report a three-year-old female with global developmental delay, hypotonia and ataxia. Through whole exome sequencing, a de novo c.1516A > G (p.Met506Val) variant in KDM5C was identified. This missense variant is in the jumonji-C domain of this multi domain protein where other missense variants have been previously reported in KDM5C related disorder. The KDM5C gene is highly intolerant to functional variation which suggests its pathogenicity. The probands motor delays and language impairment is consistent with other reported female patients with de novo variants in KDM5C. However, other features reported in females (distinctive facial features, skeletal abnormalities, short stature and endocrine features) were absent. To the best of our knowledge, our proband is the first female patient reported with a diagnosis of ataxia. Conclusions This case report provides evidence for an emerging and phenotypic variability that adds to the literature of the role of KDM5C in females with neurodevelopmental disorders as well as movement disorders.

scholarly journals Spectrum of Movement Disorders in GNAO1 Encephalopathy: in-depth Phenotyping and Literature Review

2020 ◽  
Author(s):  
Soo Yeon Kim ◽  
YoungKyu Shim ◽  
Young Joon Ko ◽  
Soojin Park ◽  
Se Song Jang ◽  
...  
Keyword(s):  
Literature Review ◽  
Exome Sequencing ◽  
Developmental Delay ◽  
Whole Exome Sequencing ◽  
De Novo ◽  
Neurodevelopmental Disorder ◽  
Epileptic Encephalopathy ◽  
Global Developmental Delay ◽  
Pathogenic Variants ◽  
Whole Exome

Abstract Background GNAO1 encephalopathy is a rare neurodevelopmental disorder characterized by distinct movement presentations and early onset epileptic encephalopathy. Here, we report the in-depth phenotyping of genetically confirmed patients with GNAO1 encephalopathy, focusing on movement presentations. Results Six patients who participated in Korean Undiagnosed Disease Program were diagnosed to have pathogenic or likely pathogenic variants in GNAO1 using whole exome sequencing. All medical records and personal video clips were analyzed with a literature review. Three of the 6 patients were male. Mean follow-up duration was 39 months (range, 7–78 months) and age at last examination was 8.0 years (range, 3.3–16.9 years). Initial complaints were hypotonia or developmental delay in 5 and right-hand clumsiness in 1 patient, which were noticed at 20 months of age on average (range, 0–75 months). All patients showed global developmental delay and 4 had severely retarded development. Five patients (5/6, 83.3%) had many different movement symptoms with various onset and progression. The symptoms included stereotyped hands movement, non-epileptic myoclonus, dyskinesia, dystonia and choreoathetosis. Whole exome sequencing identified 6 different variants in GNAO1. Three were novel de novo variants and atypical presentation was noted in a patient. One variant turned out to be inherited from patient’s mother who had mosaic variant. Distinct phenotypes in patients with variant p.Glu246Lys and p.Arg209His were elucidated by in-depth phenotyping and literature review. Conclusions We reported 6 patients with GNAO1 encephalopathy showing an extremely diverse clinical spectrum on video. Some characteristic movement features identified by careful inspection may also provide important diagnostic insight and practice guidelines.

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