scholarly journals Early onset non-syndromic retinal degeneration due to variants in INPP5E: phenotypic expansion of the ciliary gene previously associated with Joubert syndrome

2020 ◽  
Author(s):  
Riccardo Sangermano ◽  
Iris Deitch ◽  
Virginie G Peter ◽  
Rola Ba-Abbad ◽  
Emily M Place ◽  
...  
Keyword(s):  
Retinal Degeneration ◽  
Early Onset ◽  
Joubert Syndrome ◽  
Phenotypic Correlation ◽  
Cone Dystrophy ◽  
Genetic Modifiers ◽  
Retinal Degenerations ◽  
Pathogenic Variants ◽  
Systemic Disorder ◽  
The Impact

Purpose: Pathogenic variants in INPP5E cause Joubert syndrome, a systemic disorder that can manifest with retinal degeneration among other clinical features. We aimed to evaluate the role of INPP5E variants in non-syndromic inherited retinal degenerations (IRDs) of varying severity. Methods: Targeted or genome sequencing were performed in 12 unrelated non-syndromic IRD families from multiple research hospitals. Detailed clinical examination was conducted in all probands. The impact of new likely pathogenic variants was modeled on a tertiary INPP5E protein structure and all the new and published variants were analyzed for their deleteriousness and phenotypic correlation. Results: Fourteen INPP5E rare alleles were detected, 12 of which were novel. Retinal degeneration in all 12 probands was clinically distinguishable on the basis of onset and severity into Leber congenital amaurosis (n=4) and a milder, later-onset rod-cone dystrophy (n=8). Two probands showed mild ciliopathy features that resolved in childhood. Analysis of the combined impact of both alleles in syndromic and non-syndromic INPP5E patients did not reveal clear genotype-phenotype correlation, suggesting involvement of genetic modifiers. Conclusions: The study expands the phenotypic spectrum of disorders due to pathogenic variants in INPP5E and describes a new disease association with previously underdiagnosed forms of early-onset non-syndromic IRD.

scholarly journals Broadening INPP5E phenotypic spectrum: detection of rare variants in syndromic and non-syndromic IRD

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Riccardo Sangermano ◽  
Iris Deitch ◽  
Virginie G. Peter ◽  
Rola Ba-Abbad ◽  
Emily M. Place ◽  
...  
Keyword(s):  
Early Onset ◽  
Rare Variants ◽  
Joubert Syndrome ◽  
Phenotypic Correlation ◽  
Genetic Modifiers ◽  
Pathogenic Variants ◽  
Phenotypic Spectrum ◽  
Spectrum Detection ◽  
Sequencing Studies ◽  
Sporadic Cases

AbstractPathogenic variants in INPP5E cause Joubert syndrome (JBTS), a ciliopathy with retinal involvement. However, despite sporadic cases in large cohort sequencing studies, a clear association with non-syndromic inherited retinal degenerations (IRDs) has not been made. We validate this association by reporting 16 non-syndromic IRD patients from ten families with bi-allelic mutations in INPP5E. Additional two patients showed early onset IRD with limited JBTS features. Detailed phenotypic description for all probands is presented. We report 14 rare INPP5E variants, 12 of which have not been reported in previous studies. We present tertiary protein modeling and analyze all INPP5E variants for deleteriousness and phenotypic correlation. We observe that the combined impact of INPP5E variants in JBTS and non-syndromic IRD patients does not reveal a clear genotype–phenotype correlation, suggesting the involvement of genetic modifiers. Our study cements the wide phenotypic spectrum of INPP5E disease, adding proof that sequence defects in this gene can lead to early-onset non-syndromic IRD.

scholarly journals Genotype-phenotype correlations in patients with de novo KCNQ2 pathogenic variants

2020 ◽  
Vol 6 (6) ◽  
pp. e528
Author(s):  
Federica Malerba ◽  
Giulio Alberini ◽  
Ganna Balagura ◽  
Francesca Marchese ◽  
Elisabetta Amadori ◽  
...  
Keyword(s):  
De Novo ◽  
Cognitive Outcome ◽  
Single Mutation ◽  
Genetic Modifiers ◽  
Seizure Onset ◽  
Pathogenic Variants ◽  
Intellectual Outcome ◽  
The Mean ◽  
Patients With Epilepsy ◽  
The Impact

ObjectiveEarly identification of de novo KCNQ2 variants in patients with epilepsy raises prognostic issues toward optimal management. We analyzed the clinical and genetic information from a cohort of patients with de novo KCNQ2 pathogenic variants to dissect genotype-phenotype correlations.MethodsPatients with de novo KCNQ2 pathogenic variants were identified from Italy, Denmark, and Belgium. Atomic resolution Kv7.2 structures were also generated using homology modeling to map the variants.ResultsWe included 34 patients with a mean age of 4.7 years. Median seizure onset was 2 days, mainly with focal seizures with autonomic signs. Twenty-two patients (65%) were seizure free at the mean age of 1.2 years. More than half of the patients (17/32) displayed severe/profound intellectual disability; however, 4 (13%) of them had a normal cognitive outcome.A total of 28 de novo pathogenic variants were identified, most missense (25/28), and clustered in conserved regions of the protein; 6 variants recurred, and 7 were novel. We did not identify a relationship between variant position and seizure offset or cognitive outcome in patients harboring missense variants. Besides, recurrent variants were associated with overlapping epilepsy features but also variable evolution regarding the intellectual outcome.ConclusionsWe highlight the complexity of variant interpretation to assess the impact of a class of de novo KCNQ2 mutations. Genetic modifiers could be implicated, but the study paradigms to successfully address the impact of each single mutation need to be developed.

scholarly journals Ciliary Genes arl13b, ahi1 and cc2d2a Differentially Modify Expression of Visual Acuity Phenotypes but do not Enhance Retinal Degeneration due to Mutation of cep290 in Zebrafish

2019 ◽  
Author(s):  
Emma M. Lessieur ◽  
Ping Song ◽  
Gabrielle C. Nivar ◽  
Ellen M. Piccillo ◽  
Joseph Fogerty ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Retinal Degeneration ◽  
Joubert Syndrome ◽  
Genetic Modifiers ◽  
Photoreceptor Degeneration ◽  
Optokinetic Response ◽  
Bardet Biedl Syndrome ◽  
Leber Congenital Amaurosis ◽  
Outer Segments ◽  
Rhodopsin Kinase

ABSTRACTMutations in the gene Centrosomal Protein 290 kDa (CEP290) result in multiple ciliopathies ranging from the neonatal lethal disorder Meckel-Gruber Syndrome to multi-systemic disorders such as Joubert Syndrome and Bardet-Biedl Syndrome to nonsyndromic diseases like Leber Congenital Amaurosis (LCA) and retinitis pigmentosa. Results from model organisms and human genetics studies, have suggest that mutations in genes encoding protein components of the transition zone (TZ) and other cilia-associated proteins can function as genetic modifiers and be a source for CEP290 pleiotropy. We investigated the zebrafish cep290fh297/fh297 mutant, which encodes a nonsense mutation (p.Q1217*). This mutant is viable as adults, exhibits scoliosis, and undergoes a slow, progressive cone degeneration. The cep290fh297/fh297 mutants showed partial mislocalization of the transmembrane protein rhodopsin but not of the prenylated proteins rhodopsin kinase (GRK1) or the rod transducin subunit GNB1. Surprisingly, photoreceptor degeneration did not trigger proliferation of Müller glia, but proliferation of rod progenitors in the outer nuclear layer was significantly increased. To determine if heterozygous mutations in other cilia genes could exacerbate retinal degeneration, we bred cep290fh297/fh297 mutants to arl13b, ahi1, and cc2d2a mutant zebrafish lines. While cep290fh297/fh297 mutants lacking a single allele of these genes did not exhibit accelerated photoreceptor degeneration, loss of one alleles of arl13b or ahi1 reduced visual performance in optokinetic response assays at 5 days post fertilization. Our results indicate that the cep290fh297/fh297 mutant is a useful model to study the role of genetic modifiers on photoreceptor degeneration in zebrafish and to explore how progressive photoreceptor degeneration influences regeneration in adult zebrafish.Nonstandard abbreviationsBBSBardet-Biedl SyndromeCOScone outer segmentsDpfDays post fertilizationGNB1rod transducin β subunitGRK1rhodopsin kinaseJTBSJoubert SyndromeLCALeber Congenital AmaurosisMKSMeckel SyndromeNPHPnephronophthisisOKRoptokinetic responsePNApeanut agglutinin lectinROSrod outer segmentsRP2Retinitis Pigmentosa 2

scholarly journals Identification of Four Novel Variants and Determination of Genotype–Phenotype Correlations for ABCA4 Variants Associated With Inherited Retinal Degenerations

2021 ◽  
Vol 9 ◽  
Author(s):  
Qing Zhu ◽  
Xue Rui ◽  
Ya Li ◽  
Ya You ◽  
Xun-Lun Sheng ◽  
...  
Keyword(s):  
Splice Site Mutation ◽  
Missense Variant ◽  
Cone Dystrophy ◽  
Missense Mutations ◽  
Site Mutation ◽  
Targeted Next Generation Sequencing ◽  
Retinal Degenerations ◽  
Pathogenic Variants ◽  
Physico Chemical ◽  
Type 3

PurposeThe purpose of the study is to describe the genetic and clinical features of 17 patients with ABCA4-related inherited retinal degenerations (IRDs) and define the phenotype–genotype correlations.MethodsIn this multicenter retrospective study, 17 patients from 16 families were enrolled, and ABCA4 gene variants were detected using targeted next-generation sequencing using a custom designed panel for IRDs. Sanger sequencing and co-segregation analysis of the suspected pathogenic variants were performed with the family members. The pathogenicities of variants were evaluated according to the American College of Medical Genetics and Genomics guidelines (ACMG). Protein structure modifications mediated by the variants were studied using bioinformatic analyses.ResultsThe probands were diagnosed with Stargardt disease 1 (7), cone-rod dystrophy type 3 (8), cone dystrophy (1), and retinitis pigmentosa 19 (1). Onset of symptoms occurred between 5 and 27 years of age (median age = 12.4 years). A total of 30 unique ABCA4 suspicious pathogenic variations were observed, including 18 missense mutations, seven frameshift mutations, two nonsense mutations, one canonical splice site mutation, one small in-frame deletion, and one insertion. Four novel ABCA4 variants were identified. Two novel frameshift variants, c.1290dupC (p.W431fs), and c.2967dupT (G990fs), were determined to be pathogenic. A novel missense variant c.G5761T (p.V1921L) was likely pathogenic, and another novel missense c.C170G (p.P57R) variant was of undetermined significance. All ABCA4 variants tested in this study inordinately changed the physico-chemical parameters and structure of protein based on in silico analysis.ConclusionABCA4-related IRD is genetically and clinically highly heterogeneous. Four novel ABCA4 variants were identified. This study will expand the spectrum of disease-causing variants in ABCA4, which will further facilitate genetic counseling.

scholarly journals Genetic analysis of 10 pedigrees with inherited retinal degeneration by exome sequencing and phenotype-genotype association

2017 ◽  
Vol 49 (4) ◽  
pp. 216-229 ◽  
Author(s):  
Pooja Biswas ◽  
Jacque L. Duncan ◽  
Bruno Maranhao ◽  
Igor Kozak ◽  
Kari Branham ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Retinal Degeneration ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Control Sample ◽  
Compound Heterozygous ◽  
Illumina Hiseq ◽  
Retinal Degenerations ◽  
Pathogenic Variants ◽  
Causal Variants

Our purpose was to identify causative mutations and characterize the phenotype associated with the genotype in 10 unrelated families with autosomal recessive retinal degeneration. Ophthalmic evaluation and DNA isolation were carried out in 10 pedigrees with inherited retinal degenerations (IRD). Exomes of probands from eight pedigrees were captured using Nimblegen V2/V3 or Agilent V5+UTR kits, and sequencing was performed on Illumina HiSeq. The DHDDS gene was screened for mutations in the remaining two pedigrees with Ashkenazi Jewish ancestry. Exome variants were filtered to detect candidate causal variants using exomeSuite software. Segregation and ethnicity-matched control sample analysis were performed by dideoxy sequencing. Retinal histology of a patient with DHDDS mutation was studied by microscopy. Genetic analysis identified six known mutations in ABCA4 (p.Gly1961Glu, p.Ala1773Val, c.5461–10T>C), RPE65 (p.Tyr249Cys, p.Gly484Asp), PDE6B (p.Lys706Ter) and DHDDS (p.Lys42Glu) and ten novel potentially pathogenic variants in CERKL (p.Met323Val fsX20), RPE65 (p.Phe252Ser, Thr454Leu fsX31), ARL6 (p.Arg121His), USH2A (p.Gly3142Ter, p.Cys3294Trp), PDE6B (p.Gln652Ter), and DHDDS (p.Thr206Ala) genes. Among these, variants/mutations in two separate genes were observed to segregate with IRD in two pedigrees. Retinal histopathology of a patient with a DHDDS mutation showed severe degeneration of retinal layers with relative preservation of the retinal pigment epithelium. Analysis of exome variants in ten pedigrees revealed nine novel potential disease-causing variants and nine previously reported homozygous or compound heterozygous mutations in the CERKL, ABCA4, RPE65, ARL6, USH2A, PDE6B, and DHDDS genes. Mutations that could be sufficient to cause pathology were observed in more than one gene in one pedigree.

scholarly journals AB0008 THE IMPACT OF STAT4 RS7574865, IL6 RS1800795, IL6R RS2228145 AND RS4845618 ON RHEUMATOID ARTHRITIS SUSCEPTIBILITY IN BELARUSIAN POPULATION

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1307.1-1308
Author(s):  
E. Siniauskaya ◽  
T. Kuzhir ◽  
V. Yagur ◽  
R. Goncharova
Keyword(s):  
Rheumatoid Arthritis ◽  
Blood Donors ◽  
Genetic Model ◽  
Online Tool ◽  
Genotype Frequencies ◽  
Systemic Disorder ◽  
Autoimmune Pathogenesis ◽  
The Impact ◽  
Arthritis Susceptibility

Background:Rheumatoid arthritis (RA) is a chronic systemic disorder of the connective tissue of still unknown aetiology and complex autoimmune pathogenesis that primarily affects small joints. HLA alleles provide for 11-37% of the RA heritability, suggesting the substantial role of the non-HLA loci in genetic predisposition to RA. Among non-HLA loci,IL6, IL6RandSTAT4genes attract attention, however, the data concerning their influence on RA risk are somewhat contradictory.Objectives:The aim of the study was to analyze the involvement of four SNPs (STAT4rs7574865,IL6rs1800795,IL6Rrs2228145 and rs4845618) in RA susceptibility.Methods:187 patients diagnosed with RA (mean age 58.2 ± 11.9), and 380 healthy blood donors (mean age 37.18 ± 10.69 years) were included into the study. DNA extraction from peripheral blood samples was performed using the phenol-chloroform method. SNPs were genotyped using the real-time PCR with fluorescent probes. The allele and genotype frequencies were compared using the χ2 test. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using the VassarStats online tool.Results:Utilizing recessive genetic model we found an association between TT genotype ofSTAT4rs7574865 (OR = 2.362; 95%CI [1.0378 – 5.376], p = 0.038) and RA. ForIL6rs1800795, it was found that CC genotype had significantly higher frequency among patients with rheumatoid arthritis as compared to that in controls (OR = 1.52; 95%CI [1.02 – 2.27], p = 0.0456). No associations ofIL6Rrs2228145 and rs4845618 SNPs with risk of RA were found in the total group of patients vs. controls. It was also shown thatIL6rs1800795 CC genotype frequency was significantly higher among the patients with RF-negative status (p = 0.0019).Conclusion:Thus, we provide evidence for association of theSTAT4rs7574865 andIL6rs1800795 variants with risk of RA in the Belarusian population, some features of interplay being revealed between gene polymorphisms analyzed and RA antibody status. Abovementioned SNPs may contribute to RA genetic susceptibility in the Belarusian population.Disclosure of Interests:None declared

scholarly journals Myopia-26, the female-limited form of early-onset high myopia, occurring in a European family

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Noémi Széll ◽  
Tamás Fehér ◽  
Zoltán Maróti ◽  
Tibor Kalmár ◽  
Dóra Latinovics ◽  
...  
Keyword(s):  
Middle Ages ◽  
Early Onset ◽  
Colour Vision ◽  
High Myopia ◽  
Field Testing ◽  
Cone Dystrophy ◽  
Ophthalmological Examination ◽  
Whole Exome ◽  
Caucasian Family ◽  
Cone System

Abstract Background Female-limited early-onset high myopia, also called Myopia-26 is a rare monogenic disorder characterized by severe short sightedness starting in early childhood and progressing to blindness potentially by the middle ages. Despite the X-linked locus of the mutated ARR3 gene, the disease paradoxically affects females only, with males being asymptomatic carriers. Previously, this disease has only been observed in Asian families and has not gone through detailed investigation concerning collateral symptoms or pathogenesis. Results We found a large Hungarian family displaying female-limited early-onset high myopia. Whole exome sequencing of two individuals identified a novel nonsense mutation (c.214C>T, p.Arg72*) in the ARR3 gene. We carried out basic ophthalmological testing for 18 family members, as well as detailed ophthalmological examination (intraocular pressure, axial length, fundus appearance, optical coherence tomography, visual field- testing) as well as colour vision- and electrophysiology tests (standard and multifocal electroretinography, pattern electroretinography and visual evoked potentials) for eight individuals. Ophthalmological examinations did not reveal any signs of cone dystrophy as opposed to animal models. Electrophysiology and colour vision tests similarly did not evidence a general cone system alteration, rather a central macular dysfunction affecting both the inner and outer (postreceptoral and receptoral) retinal structures in all patients with ARR3 mutation. Conclusions This is the first description of a Caucasian family displaying Myopia-26. We present two hypotheses that could potentially explain the pathomechanism of this disease.

scholarly journals Novel deep intronic mutation in PLA2G6 causing early-onset Parkinson’s disease with brain iron accumulation through pseudo-exon activation

Neurogenetics ◽  
2021 ◽  
Author(s):  
Chiara Cavestro ◽  
Celeste Panteghini ◽  
Chiara Reale ◽  
Alessia Nasca ◽  
Silvia Fenu ◽  
...  
Keyword(s):  
Early Onset ◽  
Cerebellar Atrophy ◽  
Iron Accumulation ◽  
Brain Iron ◽  
Causative Gene ◽  
Coding Regions ◽  
Aberrant Transcript ◽  
Pathogenic Variants ◽  
Intronic Mutation ◽  
Mrna Analysis

AbstractPLA2G6 is the causative gene for a group of autosomal recessive neurodegenerative disorders known as PLA2G6-associated neurodegeneration (PLAN). We present a case with early-onset parkinsonism, ataxia, cognitive decline, cerebellar atrophy, and brain iron accumulation. Sequencing of PLA2G6 coding regions identified only a heterozygous nonsense variant, but mRNA analysis revealed the presence of an aberrant transcript isoform due to a novel deep intronic variant (c.2035-274G > A) leading to activation of an intronic pseudo-exon. These results expand the genotypic spectrum of PLAN, showing the paramount importance of detecting possible pathogenic variants in deep intronic regions in undiagnosed patients.

scholarly journals High likelihood of actionable pathogenic variant detection in breast cancer genes in women with very early onset breast cancer

2021 ◽  
pp. jmedgenet-2020-107347
Author(s):  
D Gareth Evans ◽  
Elke Maria van Veen ◽  
Helen J Byers ◽  
Sarah J Evans ◽  
George J Burghel ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Early Onset ◽  
Ductal Carcinoma ◽  
Cancer Genes ◽  
Early Onset Breast Cancer ◽  
Younger Women ◽  
Pathogenic Variants ◽  
Younger Age ◽  
Predisposition Genes

BackgroundWhile the likelihood of identifying constitutional breast cancer-associated BRCA1, BRCA2 and TP53 pathogenic variants (PVs) increases with earlier diagnosis age, little is known about the correlation with age at diagnosis in other predisposition genes. Here, we assessed the contribution of known breast cancer-associated genes to very early onset disease.MethodsSequencing of BRCA1, BRCA2, TP53 and CHEK2 c.1100delC was undertaken in women with breast cancer diagnosed ≤30 years. Those testing negative were screened for PVs in a minimum of eight additional breast cancer-associated genes. Rates of PVs were compared with cases ≤30 years from the Prospective study of Outcomes in Sporadic vs Hereditary breast cancer (POSH) study.ResultsTesting 379 women with breast cancer aged ≤30 years identified 75 PVs (19.7%) in BRCA1, 35 (9.2%) in BRCA2, 22 (5.8%) in TP53 and 2 (0.5%) CHEK2 c.1100delC. Extended screening of 184 PV negative women only identified eight additional actionable PVs. BRCA1/2 PVs were more common in women aged 26–30 years than in younger women (p=0.0083) although the younger age group had rates more similar to those in the POSH cohort. Out of 26 women with ductal carcinoma in situ (DCIS) alone, most were high-grade and 11/26 (42.3%) had a PV (TP53=6, BRCA2=2, BRCA1=2, PALB2=1). This PV yield is similar to the 61 (48.8%) BRCA1/2 PVs identified in 125 women with triple-negative breast cancer. The POSH cohort specifically excluded pure DCIS which may explain lower TP53 PV rates in this group (1.7%).ConclusionThe rates of BRCA1, BRCA2 and TP53 PVs are high in very early onset breast cancer, with limited benefit from testing of additional breast cancer-associated genes.

scholarly journals Genetic and immunologic findings in children with recurrent aphthous stomatitis with systemic inflammation

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Martina Girardelli ◽  
Erica Valencic ◽  
Valentina Moressa ◽  
Roberta Margagliotta ◽  
Alessandra Tesser ◽  
...  
Keyword(s):  
Clinical Diagnosis ◽  
Systemic Inflammation ◽  
Lupus Erythematosus ◽  
Early Onset ◽  
Disease Onset ◽  
Recurrent Aphthous Stomatitis ◽  
Aphthous Stomatitis ◽  
Monogenic Disorders ◽  
Pathogenic Variants ◽  
Targeted Treatments

Abstract Background Recurrent aphthous stomatitis with systemic signs of inflammation can be encountered in inflammatory bowel disease, Behçet’s disease (BD), Systemic Lupus Erythematosus (SLE). In addition, it has been proposed that cases with very early onset in childhood can be underpinned by rare monogenic defects of immunity, which may require targeted treatments. Thus, subjects with early onset recurrent aphthous stomatitis receiving a clinical diagnosis of BD-like or SLE-like disease may deserve a further diagnostic workout, including immunologic and genetic investigations. Objective To investigate how an immunologic, genetic and transcriptomics assessment of interferon inflammation may improve diagnosis and care in children with recurrent aphthous stomatitis with systemic inflammation. Methods Subjects referred to the pediatric rheumatologist for recurrent aphthous stomatitis associated with signs of systemic inflammation from January 2015 to January 2020 were enrolled in the study and underwent analysis of peripheral lymphocyte subsets, sequencing of a 17-genes panel and measure of interferon score. Results We enrolled 15 subjects (12 females, median age at disease onset 4 years). The clinical diagnosis was BD in 8, incomplete BD in 5, BD/SLE overlap in 1, SLE in 1. Pathogenic genetic variants were detected in 3 patients, respectively 2 STAT1 gain of function variants in two patients classified as BD/SLE overlap and SLE, and 1 TNFAIP3 mutation (A20 haploinsufficiency) in patients with BD. Moreover 2 likely pathogenic variants were identified in DNASE1L3 and PTPN22, both in patients with incomplete BD. Interferon score was high in the two patients with STAT1 GOF mutations, in the patient with TNFAIP3 mutation, and in 3 genetic-negative subjects. In two patients, the treatment was modified based on genetic results. Conclusions Although recurrent aphthous stomatitis associated with systemic inflammation may lead to a clinical diagnosis of BD or SLE, subjects with early disease onset in childhood deserve genetic investigation for rare monogenic disorders. A wider genetic panel may help disclosing the genetic background in the subset of children with increased interferon score, who tested negative in this study.

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