scholarly journals Collagen VI-Related Myopathies: Genetic and Clinical Findings

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Samaneh Maskani ◽  
Najmeh Ahangari ◽  
Mohammad Doosti ◽  
Reza Boostani ◽  
Paria Najarzadeh Torbati ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Prenatal Testing ◽  
Clinical Findings ◽  
Collagen Vi ◽  
Case Presentation ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Affected Family Member ◽  
Genes Encoding ◽  
Autosomal Recessive Manner

Introduction: Collagen VI-related disorders are a group of heterogeneous muscular diseases due to mutations within the COL6A1, COL6A2, and COL6A3 genes, encoding collagen VI as an essential component of the extracellular matrix. Here, we reported four patients affected by collagen VI-related disorders with genetic variants in COL6A genes. Case Presentation: After a comprehensive clinical examination, four unrelated patients with muscular dystrophy were referred for genetic counseling. Whole-exome sequencing followed by Insilco analysis was done for one affected individual from each family. The analysis of genomic data revealed four different mutations within the COL6A1, COL6A2, and COL6A3 genes in the affected individuals. Conclusions: According to the previous reports, limb-girdle muscular dystrophy is inherited as autosomal dominant, and congenital myosclerosis phenotype is inherited in an autosomal recessive manner. Carrier testing and prenatal testing are possible if pathogenic variants are recognized in an affected family member.

Clinical and Pathological Features of a Newborn With Compound Heterozygous ANKS6 Variants

2019 ◽  
Vol 23 (3) ◽  
pp. 235-239
Author(s):  
Sakil Kulkarni ◽  
Brooj Abro ◽  
Maria Laura Duque Lasio ◽  
Janis Stoll ◽  
Dorothy K Grange ◽  
...  
Keyword(s):  
Cardiac Failure ◽  
Renal Dysplasia ◽  
Cardiomyocyte Hypertrophy ◽  
Compound Heterozygous ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Genes Encoding ◽  
Cystic Renal Dysplasia ◽  
Cystic Renal Disease ◽  
Compound Heterozygous Variants

We report a term female infant born to nonconsanguineous parents who presented with renal failure at birth, hypothyroidism, cholestasis, and progressive cardiac dysfunction. Multigene next-generation sequencing panels for cholestasis, cardiomyopathy, and cystic renal disease did not reveal a unifying diagnosis. Whole exome sequencing revealed compound heterozygous pathogenic variants in ANKS6 (Ankyrin Repeat and Sterile Alpha Motif Domain Containing 6), which encodes a protein that interacts with other proteins of the Inv compartment of cilium ( NEK8, NPHP2/INVS, and NPHP3). ANKS6 has been shown to be important for early renal development and cardiac looping in animal models. Autopsy revealed cystic renal dysplasia and cardiomyocyte hypertrophy, disarray, and focal necrosis. Liver histology revealed cholestasis and centrilobular necrosis, which was likely a result of progressive cardiac failure. This is the first report of compound heterozygous variants in ANKS6 leading to a nephronopthisis-related ciliopathy-like phenotype. We conclude that pathogenic variants in ANKS6 may present early in life with severe renal and cardiac failure, similar to subjects with variants in genes encoding other proteins in the Inv compartment of the cilium.

Deoxyguanosine kinase deficiency: a report of four patients

2017 ◽  
Vol 30 (6) ◽  
pp. 697-702 ◽  
Author(s):  
Özlem Ünal ◽  
Burcu Hişmi ◽  
Mustafa Kılıç ◽  
Hayriye Hızarcıoğlu Gülşen ◽  
Turgay Coşkun ◽  
...  
Keyword(s):  
Elevated Serum ◽  
Clinical Findings ◽  
Case Presentation ◽  
Hepatic Involvement ◽  
Pathogenic Variants ◽  
Mitochondrial Dna Depletion ◽  
Laboratory Features ◽  
Deoxyguanosine Kinase ◽  
Iron Deposits ◽  
Liver Biopsies

AbstractBackground:Hepatic involvement is a common feature in childhood mitochondrial disorders. Deoxyguanosine kinase (DGUOK) deficiency is one of the mitochondrial DNA depletion syndromes associated with hepatocerebral syndrome. Hepatic disease and neurologic dysfunction occurs within weeks after birth. Low birth weight is one of the common features. This study aims to describe the clinical and laboratory features of four infants carrying four different pathogenic variants in theDGUOKgene.Case presentation:Common clinical findings were progressive cholestatic liver failure, hypoglycemia, hypotonia and rotatory nystagmus in our DGUOK deficiency patients. Lactic acidosis, elevated serum tyrosine and ferritin levels were the striking laboratory features. Cholestasis, iron deposits, microvesicular steatosis and fibrosis were the histopathological findings seen in liver biopsies of two patients. All patients died with multi-organ failure between the ages of 42 days and 6 months.Conclusions:While neurologic findings may occur later in the course of the disease, elevated serum tyrosine levels may alert the physicians to a DGUOK deficiency in a baby with hepatopathy in the presence of the mentioned signs. Early diagnosis is important not only for genetic counseling but also for a possible liver transplantation.

scholarly journals B.06 Whole exome sequencing in genetic ataxias associated with cerebellar atrophy: the Canadian experience

2019 ◽  
Vol 46 (s1) ◽  
pp. S11
Author(s):  
L Gauquelin ◽  
T Hartley ◽  
M Tarnopolsky ◽  
DA Dyment ◽  
B Brais ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Diagnostic Yield ◽  
Genetic Diseases ◽  
Genetic Diagnosis ◽  
Cerebellar Atrophy ◽  
Clinical Findings ◽  
Disease Genes ◽  
Pathogenic Variants ◽  
Whole Exome

Background: Cerebellar atrophy is characterized by loss of cerebellar tissue, with evidence on brain imaging of enlarged interfolial spaces compared to the foliae. Genetic ataxias associated with cerebellar atrophy are a heterogeneous group of disorders. We investigated the prevalence in Canada and the diagnostic yield of whole exome sequencing (WES) for this group of conditions. Methods: Between 2011 and 2017, WES was performed in 91 participants with cerebellar atrophy as part of one of two national research programs, Finding of Rare Genetic Disease Genes (FORGE) or Enhanced Care for Rare Genetic Diseases in Canada (Care4Rare). Results: A genetic diagnosis was established in 58% of cases (53/91). Pathogenic variants were found in 24 known genes, providing a diagnosis for 46/53 participants (87%), and in four novel genes, accounting for 7/53 cases (13%). 38/91 cases (42%) remained unsolved. The most common diagnoses were channelopathies in 12/53 patients (23%) and mitochondrial disorders in 9/53 (17%). Inheritance was autosomal recessive in the majority of cases. Additional clinical findings provided useful clues to some of the diagnoses. Conclusions: This is the first report on the prevalence of genetic ataxias associated with cerebellar atrophy in Canada, and the utility of WES for this group of conditions.

scholarly journals Mutations in genes encoding regulators of mRNA decapping and translation initiation: links to intellectual disability

2020 ◽  
Vol 48 (3) ◽  
pp. 1199-1211 ◽  
Author(s):  
Dominique Weil ◽  
Amélie Piton ◽  
Davor Lessel ◽  
Nancy Standart
Keyword(s):  
Intellectual Disability ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Sequencing Data ◽  
Rna Helicases ◽  
Mrna Decapping ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Genes Encoding ◽  
Post Transcriptional Regulation

Intellectual disability (ID) affects at least 1% of the population, and typically presents in the first few years of life. ID is characterized by impairments in cognition and adaptive behavior and is often accompanied by further delays in language and motor skills, as seen in many neurodevelopmental disorders (NDD). Recent widespread high-throughput approaches that utilize whole-exome sequencing or whole-genome sequencing have allowed for a considerable increase in the identification of these pathogenic variants in monogenic forms of ID. Notwithstanding this progress, the molecular and cellular consequences of the identified mutations remain mostly unknown. This is particularly important as the associated protein dysfunctions are the prerequisite to the identification of targets for novel drugs of these rare disorders. Recent Next-Generation sequencing-based studies have further established that mutations in genes encoding proteins involved in RNA metabolism are a major cause of NDD. Here, we review recent studies linking germline mutations in genes encoding factors mediating mRNA decay and regulators of translation, namely DCPS, EDC3, DDX6 helicase and ID. These RNA-binding proteins have well-established roles in mRNA decapping and/or translational repression, and the mutations abrogate their ability to remove 5′ caps from mRNA, diminish their interactions with cofactors and stabilize sub-sets of transcripts. Additional genes encoding RNA helicases with roles in translation including DDX3X and DHX30 have also been linked to NDD. Given the speed in the acquisition, analysis and sharing of sequencing data, and the importance of post-transcriptional regulation for brain development, we anticipate mutations in more such factors being identified and functionally characterized.

scholarly journals Contribution of SLC22A12 on hypouricemia and its clinical significance for screening purposes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Do Hyeon Cha ◽  
Heon Yung Gee ◽  
Raul Cachau ◽  
Jong Mun Choi ◽  
Daeui Park ◽  
...  
Keyword(s):  
Genetic Diagnosis ◽  
Kidney Injury ◽  
Genetic Identification ◽  
Diagnostic Screening ◽  
Renal Hypouricemia ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Causal Variants ◽  
Coding Variants ◽  
Independent Cohort

Abstract Differentiating between inherited renal hypouricemia and transient hypouricemic status is challenging. Here, we aimed to describe the genetic background of hypouricemia patients using whole-exome sequencing (WES) and assess the feasibility for genetic diagnosis using two founder variants in primary screening. We selected all cases (N = 31) with extreme hypouricemia (<1.3 mg/dl) from a Korean urban cohort of 179,381 subjects without underlying conditions. WES and corresponding downstream analyses were performed for the discovery of rare causal variants for hypouricemia. Two known recessive variants within SLC22A12 (p.Trp258*, pArg90His) were identified in 24 out of 31 subjects (77.4%). In an independent cohort, we identified 50 individuals with hypouricemia and genotyped the p.Trp258* and p.Arg90His variants; 47 of the 50 (94%) hypouricemia cases were explained by only two mutations. Four novel coding variants in SLC22A12, p.Asn136Lys, p.Thr225Lys, p.Arg284Gln, and p.Glu429Lys, were additionally identified. In silico studies predict these as pathogenic variants. This is the first study to show the value of genetic diagnostic screening for hypouricemia in the clinical setting. Screening of just two ethnic-specific variants (p.Trp258* and p.Arg90His) identified 87.7% (71/81) of Korean patients with monogenic hypouricemia. Early genetic identification of constitutive hypouricemia may prevent acute kidney injury by avoidance of dehydration and excessive exercise.

scholarly journals Whole-exome sequencing with targeted analysis and epilepsy after acute symptomatic neonatal seizures

2021 ◽  
Author(s):  
Adam L. Numis ◽  
Gilberto da Gente ◽  
Elliott H. Sherr ◽  
Hannah C. Glass
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
De Novo ◽  
List Type ◽  
Sequencing Analysis ◽  
Neonatal Seizures ◽  
Pathogenic Variants ◽  
Targeted Analysis ◽  
Whole Exome ◽  
Epilepsy Gene

Abstract Background The contribution of pathogenic gene variants with development of epilepsy after acute symptomatic neonatal seizures is not known. Methods Case–control study of 20 trios in children with a history of acute symptomatic neonatal seizures: 10 with and 10 without post-neonatal epilepsy. We performed whole-exome sequencing (WES) and identified pathogenic de novo, transmitted, and non-transmitted variants from established and candidate epilepsy association genes and correlated prevalence of these variants with epilepsy outcomes. We performed a sensitivity analysis with genes associated with coronary artery disease (CAD). We analyzed variants throughout the exome to evaluate for differential enrichment of functional properties using exploratory KEGG searches. Results Querying 200 established and candidate epilepsy genes, pathogenic variants were identified in 5 children with post-neonatal epilepsy yet in only 1 child without subsequent epilepsy. There was no difference in the number of trios with non-transmitted pathogenic variants in epilepsy or CAD genes. An exploratory KEGG analysis demonstrated a relative enrichment in cell death pathways in children without subsequent epilepsy. Conclusions In this pilot study, children with epilepsy after acute symptomatic neonatal seizures had a higher prevalence of coding variants with a targeted epilepsy gene sequencing analysis compared to those patients without subsequent epilepsy. Impact We performed whole-exome sequencing (WES) in 20 trios, including 10 children with epilepsy and 10 without epilepsy, both after acute symptomatic neonatal seizures. Children with post-neonatal epilepsy had a higher burden of pathogenic variants in epilepsy-associated genes compared to those without post-neonatal epilepsy. Future studies evaluating this association may lead to a better understanding of the risk of epilepsy after acute symptomatic neonatal seizures and elucidate molecular pathways that are dysregulated after brain injury and implicated in epileptogenesis.

scholarly journals Skeletal and Cardiac Muscle Disorders Caused by Mutations in Genes Encoding Intermediate Filament Proteins

2021 ◽  
Vol 22 (8) ◽  
pp. 4256
Author(s):  
Lorenzo Maggi ◽  
Manolis Mavroidis ◽  
Stelios Psarras ◽  
Yassemi Capetanaki ◽  
Giovanna Lattanzi
Keyword(s):  
Muscular Dystrophy ◽  
Cardiac Muscle ◽  
Intermediate Filament ◽  
Striated Muscle ◽  
Congenital Muscular Dystrophy ◽  
Left Ventricular ◽  
Intermediate Filament Proteins ◽  
Muscle Disorders ◽  
Genes Encoding ◽  
Molecular Aspects

Intermediate filaments are major components of the cytoskeleton. Desmin and synemin, cytoplasmic intermediate filament proteins and A-type lamins, nuclear intermediate filament proteins, play key roles in skeletal and cardiac muscle. Desmin, encoded by the DES gene (OMIM *125660) and A-type lamins by the LMNA gene (OMIM *150330), have been involved in striated muscle disorders. Diseases include desmin-related myopathy and cardiomyopathy (desminopathy), which can be manifested with dilated, restrictive, hypertrophic, arrhythmogenic, or even left ventricular non-compaction cardiomyopathy, Emery–Dreifuss Muscular Dystrophy (EDMD2 and EDMD3, due to LMNA mutations), LMNA-related congenital Muscular Dystrophy (L-CMD) and LMNA-linked dilated cardiomyopathy with conduction system defects (CMD1A). Recently, mutations in synemin (SYNM gene, OMIM *606087) have been linked to cardiomyopathy. This review will summarize clinical and molecular aspects of desmin-, lamin- and synemin-related striated muscle disorders with focus on LMNA and DES-associated clinical entities and will suggest pathogenetic hypotheses based on the interplay of desmin and lamin A/C. In healthy muscle, such interplay is responsible for the involvement of this network in mechanosignaling, nuclear positioning and mitochondrial homeostasis, while in disease it is disturbed, leading to myocyte death and activation of inflammation and the associated secretome alterations.

scholarly journals Genotype-Phenotype Correlations in RP1-Associated Retinal Dystrophies: A Multi-Center Cohort Study in JAPAN

2021 ◽  
Vol 10 (11) ◽  
pp. 2265
Author(s):  
Kei Mizobuchi ◽  
Takaaki Hayashi ◽  
Noriko Oishi ◽  
Daiki Kubota ◽  
Shuhei Kameya ◽  
...  
Keyword(s):  
Age At Onset ◽  
Japanese Patients ◽  
Clinical Findings ◽  
Cone Dystrophy ◽  
Element Insertion ◽  
Retinal Dystrophies ◽  
Whole Exome ◽  
Novel Variants ◽  
Alu Element ◽  
Frequent Variant

Background: Little is known about genotype–phenotype correlations of RP1-associated retinal dystrophies in the Japanese population. We aimed to investigate the genetic spectrum of RP1 variants and provide a detailed description of the clinical findings in Japanese patients. Methods: In total, 607 patients with inherited retinal diseases were examined using whole-exome/whole-genome sequencing (WES/WGS). PCR-based screening for an Alu element insertion (c.4052_4053ins328/p.Tyr1352AlafsTer9) was performed in 18 patients with autosomal-recessive (AR)-retinitis pigmentosa (RP) or AR-cone dystrophy (COD)/cone-rod dystrophy (CORD), including seven patients with heterozygous RP1 variants identified by WES/WGS analysis, and 11 early onset AR-RP patients, in whom no pathogenic variant was identified. We clinically examined 25 patients (23 families) with pathogenic RP1 variants, including five patients (five families) with autosomal-dominant (AD)-RP, 13 patients (11 families) with AR-RP, and seven patients (seven families) with AR-COD/CORD. Results: We identified 18 pathogenic RP1 variants, including seven novel variants. Interestingly, the Alu element insertion was the most frequent variant (32.0%, 16/50 alleles). The clinical findings revealed that the age at onset and disease progression occurred significantly earlier and faster in AR-RP patients compared to AD-RP or AR-COD/CORD patients. Conclusions: Our results suggest a genotype–phenotype correlation between variant types/locations and phenotypes (AD-RP, AR-RP, and AR-COD/CORD), and the Alu element insertion was the most major variant in Japanese patients with RP1-associated retinal dystrophies.

scholarly journals A Broader Perspective on the Prenatal Diagnosis of Cornelia de Lange Syndrome: Review of the Literature and Case Presentation

Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 142
Author(s):  
Anca Maria Panaitescu ◽  
Simona Duta ◽  
Nicolae Gica ◽  
Radu Botezatu ◽  
Florina Nedelea ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Cornelia De Lange Syndrome ◽  
Facial Features ◽  
Genetic Condition ◽  
Case Presentation ◽  
Pathogenic Variants ◽  
Limb Reduction ◽  
Ultrasound Findings ◽  
Prenatal Management ◽  
Cornelia De Lange

Cornelia de Lange syndrome (CDLS) is caused by pathogenic variants in genes which are structural or regulatory components of the cohesin complex. The classical Cornelia de Lange (CDLS) phenotype is characterized by distinctive facial features, growth retardation, upper limb reduction defects, hirsutism, and developmental delay. Non-classical phenotypes make this condition heterogeneous. Although CDLS is a heterogeneous clinical and genetic condition, clear diagnostic criteria have been described by specialist consensus. Many of these criteria refer to features that can be seen on prenatal ultrasound. The aim of this paper is twofold: to present the ultrasound findings in fetuses affected by CDLS syndrome; to discuss the recent advances and the limitations in the ultrasound and genetic prenatal diagnosis of CDLS. Our review aims to offer, apart from the data needed to understand the genetics and the prenatal presentation of the disease, a joint perspective of the two specialists involved in the prenatal management of this pathology: the fetal medicine specialist and the geneticist. To better illustrate the data presented, we also include a representative clinical case.

scholarly journals Spondylocarpotarsal synostosis syndrome due to a novel loss of function FLNB variant: a case report

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Samina Yasin ◽  
Outi Makitie ◽  
Sadaf Naz
Keyword(s):  
Short Stature ◽  
Autosomal Recessive ◽  
Autosomal Recessive Disorder ◽  
Loss Of Function ◽  
Case Presentation ◽  
Pathogenic Variants ◽  
Skeletal Malformations ◽  
Tarsal Bones ◽  
The Family ◽  
Heterozygous Carriers

Abstract Background Loss of function or gain of function variants of Filamin B (FLNB) cause recessive or dominant skeletal disorders respectively. Spondylocarpotarsal synostosis syndrome (SCT) is a rare autosomal recessive disorder characterized by short stature, fused vertebrae and fusion of carpal and tarsal bones. We present a novel FLNB homozygous pathogenic variant and present a carrier of the variant with short height. Case presentation We describe a family with five patients affected with skeletal malformations, short stature and vertebral deformities. Exome sequencing revealed a novel homozygous frameshift variant c.2911dupG p.(Ala971GlyfsTer122) in FLNB, segregating with the phenotype in the family. The variant was absent in public databases and 100 ethnically matched control chromosomes. One of the heterozygous carriers of the variant had short stature. Conclusion Our report expands the genetic spectrum of FLNB pathogenic variants. It also indicates a need to assess the heights of other carriers of FLNB recessive variants to explore a possible role in idiopathic short stature.

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