scholarly journals Novel compound heterozygous pathogenic variants in ASCC1 in a Chinese patient with spinal muscular atrophy with congenital bone fractures 2 : evidence supporting a "Definitive" gene-disease relationship

2019 ◽  
Author(s):  
Weiliang Lu ◽  
Mingxing Liang ◽  
Jiasun Su ◽  
Jin Wang ◽  
Lingxiao Li ◽  
...  
Keyword(s):  
Spinal Muscular Atrophy ◽  
Exome Sequencing ◽  
Disease Gene ◽  
Bone Fractures ◽  
Muscular Atrophy ◽  
Chinese Patient ◽  
Chinese Family ◽  
Compound Heterozygous ◽  
Pathogenic Variants ◽  
Limited Spectrum

Abstract Background: A very limited spectrum of ASCC1 pathogenic variants had been reported in five (mostly consanguineous) families with spinal muscular atrophy with congenital bone fractures 2 [OMIM #616867] since 2016. Methods:A proband from a non-consanguineous Chinese family presented with neonatal severe hypotonia, respiratory distress, muscle weakness and atrophy, as well as congenital bone fractures was examined by exome sequencing. Results: A compound heterozygosity of a nonsense (c.932C>G ,p.Ser311Ter) and an exon 5 deletion in ASCC1 segregating with phenotypes was detected, both variants are novel and pathogenic. Since ASCC1 is a relative new disease gene, we performed the gene curation following ClinGen SOP. The existing evidence is sufficient to support a "Definitive" level of disease-gene relationship. Conclusion: This case report expended the mutation spectrum of ASCC1 and support the notion that this novel disease also occur in outbreed populations and this is a rare disease but may still be underdiagnosed due to its perinatal lethal outcomes. Keywords: spinal muscular atrophy with congenital bone fractures 2; ASCC1 ; compound heterozygous; gene curation; exome sequencing

scholarly journals Intragenic variants in the SMN1 gene determine the clinical phenotype in 5q spinal muscular atrophy

2020 ◽  
Vol 6 (5) ◽  
pp. e505
Author(s):  
Rodrigo de Holanda Mendonça ◽  
Ciro Matsui ◽  
Graziela Jorge Polido ◽  
André Macedo Serafim Silva ◽  
Leslie Kulikowski ◽  
...  
Keyword(s):  
Spinal Muscular Atrophy ◽  
Copy Number ◽  
Clinical Phenotype ◽  
Muscular Atrophy ◽  
Large Population ◽  
Survival Motor Neuron ◽  
Compound Heterozygous ◽  
Pathogenic Variants ◽  
Exon 1 ◽  
Compound Heterozygous Variants

ObjectiveThe aim of the study was to report the proportion of homozygous and compound heterozygous variants in the survival motor neuron 1 (SMN1) gene in a large population of patients with spinal muscular atrophy (SMA) and to correlate the severity of the disease with the presence of specific intragenic variants in SMN1 and with the SMN2 copy number.MethodsFour hundred fifty Brazilian patients with SMA were included in a retrospective study, and clinical data were analyzed compared with genetic data; the SMN2 copy number was obtained by multiplex ligation-dependent probe amplification and pathogenic variants in SMN1 by next-generation sequencing.ResultsFour hundred two patients (89.3%) presented homozygous exon 7-SMN1 deletion, and 48 (10.7%) were compound heterozygous for the common deletion in one allele and a point mutation in the other allele. Recurrent variants in exons 3 and 6 (c.460C>T, c.770_780dup and c.734_735insC) accounted for almost 80% of compound heterozygous patients. Another recurrent pathogenic variant was c.5C>G at exon 1. Patients with c.770_780dup and c.734_735insC had a clinical phenotype correlated with SMN2 copy number, whereas the variants c.460C>T and c.5C>G determined a milder phenotype independently of the SMN2 copies.ConclusionsPatients with specific pathogenic variants (c.460C>T and c.5C>G) presented a milder phenotype, and the SMN2 copy number did not correlate with disease severity in this group.

scholarly journals Adult-Onset Spinal Muscular Atrophy due to Mutations in the VRK1 Gene

2021 ◽  
Vol 7 (4) ◽  
pp. e599
Author(s):  
Angela Sung ◽  
Paolo Moretti ◽  
Aziz Shaibani
Keyword(s):  
Spinal Muscular Atrophy ◽  
Muscular Atrophy ◽  
Gene Mutations ◽  
Molecular Data ◽  
Clinical Syndrome ◽  
Compound Heterozygous ◽  
Adult Onset ◽  
Pathogenic Variants ◽  
Neurologic Disorders ◽  
Progressive Weakness

ObjectiveTo expand our knowledge of the range of clinical phenotypes associated with vaccinia-related kinase 1 (VRK1) gene mutations.MethodsWe present clinical and molecular data of 2 individuals with slowly progressive weakness and a clinical syndrome consistent with adult-onset spinal muscular atrophy without pontocerebellar atrophy.ResultsGenetic testing revealed likely pathogenic variants in the VRK1 gene in both subjects. One individual carried homozygous p.R321C (c.961 C>T), likely pathogenic variants. The other carried compound heterozygous p.V236M (c.706 G>A) and p.R321C (c.961 C>T), likely pathogenic variants. Notably, both patients were of Hispanic descent.ConclusionsWe report 2 cases with VRK1 mutations presenting as adult-onset spinal muscular atrophy without pontocerebellar hypoplasia and review the current literature of similar cases. Our report expands the clinical spectrum of neurologic disorders associated with VRK1 mutations.

scholarly journals DNAH11 compound heterozygous variants cause heterotaxy and congenital heart disease

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252786
Author(s):  
Hong Xia ◽  
Xiangjun Huang ◽  
Sheng Deng ◽  
Hongbo Xu ◽  
Yan Yang ◽  
...  
Keyword(s):  
Congenital Heart Disease ◽  
Heart Disease ◽  
Exome Sequencing ◽  
Sanger Sequencing ◽  
Congenital Heart ◽  
Chinese Family ◽  
Compound Heterozygous ◽  
Internal Organs ◽  
Pathogenic Variants ◽  
Compound Heterozygous Variants

Heterotaxy (HTX), a condition characterized by internal organs not being arranged as expected relative to each other and to the left-right axis, is often accompanied with congenital heart disease (CHD). The purpose was to detect the pathogenic variants in a Chinese family with HTX and CHD. A non-consanguineous Han Chinese family with HTX and CHD, and 200 unrelated healthy subjects were enlisted. Exome sequencing and Sanger sequencing were applied to identify the genetic basis of the HTX family. Compound heterozygous variants, c.3426-1G>A and c.4306C>T (p.(Arg1436Trp)), in the dynein axonemal heavy chain 11 gene (DNAH11) were identified in the proband via exome sequencing and further confirmed by Sanger sequencing. Neither c.3426-1G>A nor c.4306C>T variant in the DNAH11 gene was detected in 200 healthy controls. The DNAH11 c.3426-1G>A variant was predicted as altering the acceptor splice site and most likely affecting splicing. The DNAH11 c.4306C>T variant was predicted to be damaging, which may reduce the phenotype severity. The compound heterozygous variants, c.3426-1G>A and c.4306C>T, in the DNAH11 gene might be the pathogenic alterations resulting in HTX and CHD in this family. These findings broaden the variant spectrum of the DNAH11 gene and increase knowledge used in genetic counseling for the HTX family.

scholarly journals Case Report: Whole-Exome Sequencing With MLPA Revealed Variants in Two Genes in a Patient With Combined Manifestations of Spinal Muscular Atrophy and Duchenne Muscular Dystrophy

2021 ◽  
Vol 12 ◽  
Author(s):  
Yu Xia ◽  
Yijie Feng ◽  
Lu Xu ◽  
Xiaoyang Chen ◽  
Feng Gao ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Spinal Muscular Atrophy ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Muscular Atrophy ◽  
Genetic Disorder ◽  
Clinical Manifestations ◽  
Chinese Family ◽  
Whole Exome

Spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) are two common kinds of neuromuscular disorders sharing various similarities in clinical manifestations. SMA is an autosomal recessive genetic disorder that results from biallelic mutations of the survival motor neuron 1 gene (SMN1; OMIM 600354) on the 5q13 chromosome. DMD is an X-linked disorder caused by defects in the DMD gene (OMIM 300377) on the X chromosome. Here, for the first time, we report a case from a Chinese family who present with clinical manifestations of both two diseases, including poor motor development and progressive muscle weakness. We identified a homozygous deletion in exons 7 and 8 of the SMN1 gene and a deletion in exon 50 of the DMD gene by whole-exome sequencing (WES) and multiplex ligation-dependent probe amplification (MLPA). This case expands our understanding of diagnosis for synchronous SMA and DMD and highlights the importance of various genetic testing methods, including WES, in differential diagnosis of neuromuscular diseases.

scholarly journals Identification of novel pathogenic ABCA4 variants in a Han Chinese family with Stargardt disease

2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Qin Xiang ◽  
Yanna Cao ◽  
Hongbo Xu ◽  
Yi Guo ◽  
Zhijian Yang ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Sanger Sequencing ◽  
Retinal Pigment ◽  
Han Chinese ◽  
Chinese Family ◽  
Compound Heterozygous ◽  
Stargardt Disease ◽  
Pathogenic Variants ◽  
Whole Exome

Abstract Stargardt disease (STGD1, OMIM 248200) is a common hereditary juvenile or early adult onset macular degeneration. It ultimately leads to progressive central vision loss. Here, we sought to identify gene mutations associated with STGD1 in a three-generation Han Chinese pedigree by whole exome sequencing and Sanger sequencing. Two novel potentially pathogenic variants in a compound heterozygous state, c.3607G>T (p.(Gly1203Trp)) and c.6722T>C (p.(Leu2241Pro)), in the ATP binding cassette subfamily A member 4 gene (ABCA4) were identified as contributing to the family’s STGD1 phenotype. These variants may impact the ABCA4 protein structure and reduce the retinal-activated ATPase activity, leading to abnormal all-trans retinal accumulation in photoreceptor outer segments and in retinal pigment epithelium cells. The present study broadens the mutational spectrum of the ABCA4 responsible for STGD1. A combination of whole exome sequencing and Sanger sequencing is likely to be a time-saving and cost-efficient approach to screen pathogenic variants in genetic disorders caused by sizable genes, as well as avoiding misdiagnosis. These results perhaps refine genetic counseling and ABCA4-targetted treatments for families affected by STGD1.

scholarly journals A de novo SEMA6B variant in a Chinese patient with progressive myoclonic epilepsy-11 and review of the literature

2021 ◽  
Author(s):  
Qian Li ◽  
Min Liu ◽  
Dan-ping Huang ◽  
Tao Li ◽  
Jing Huang ◽  
...  
Keyword(s):  
De Novo ◽  
Chinese Patient ◽  
Myoclonic Epilepsy ◽  
Chinese Family ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Progressive Neurodegeneration ◽  
Progressive Myoclonic Epilepsy ◽  
Limited Spectrum ◽  
De Novo Variant

Abstract Progressive myoclonic epilepsy is a group of neurodegenerative diseases with complex clinical and genetic heterogeneity, which is associated with spontaneous or action-induced myoclonus and progressive neurodegeneration. Since 2020, 4 families with progressive myoclonic epilepsy-11 [OMIM#618876] have been reported with a very limited spectrum of SEMA6B pathogenic variants. In our study, whole-exome sequencing was used in a proband from a nonconsanguineous Chinese family presenting with growth retardation and recurrent atonic seizures. A deletion mutation (c.1960_1978del, p.Leu654Argfs*25) in the last exon of SEMA6B was detected, which is a de Novo variant and pathogenic. The new genetic evidence we reported here strengthened the gene-disease relationship, and the gene curation level between SEMA6B and progressive myoclonic epilepsy-11 became “strong” following the ClinGen SOP. Therefore, the results of this study broaden the mutation spectrum of SEMA6B in different ethnic groups and strengthen the gene-disease relationship between SEMA6B and progressive myoclonic epilepsy-11.

scholarly journals Mutations in Subunits of the Activating Signal Cointegrator 1 Complex Are Associated with Prenatal Spinal Muscular Atrophy and Congenital Bone Fractures

2016 ◽  
Vol 98 (3) ◽  
pp. 473-489 ◽  
Author(s):  
Ellen Knierim ◽  
Hiromi Hirata ◽  
Nicole I. Wolf ◽  
Susanne Morales-Gonzalez ◽  
Gudrun Schottmann ◽  
...  
Keyword(s):  
Spinal Muscular Atrophy ◽  
Bone Fractures ◽  
Muscular Atrophy

Intrafamilial Variability of the R694C Variant in BICD2 Presenting with Lethal Severe Arthrogryposis

2022 ◽  
pp. 097321792110688
Author(s):  
Francisco Ribeiro-Mourão ◽  
Ana Vilan ◽  
Sara Passos-Silva ◽  
Fernando Silveira ◽  
Miguel Leão ◽  
...  
Keyword(s):  
De Novo ◽  
Bone Fractures ◽  
Muscular Atrophy ◽  
Hip Dislocation ◽  
Arthrogryposis Multiplex Congenita ◽  
Pathogenic Variants ◽  
Genetic Abnormalities ◽  
Heterozygous Variant ◽  
Fetal Movements ◽  
Intrafamilial Variability

Arthrogryposis multiplex congenita (AMC) is a heterogeneous condition comprising congenital multiple joint contractures, and it is secondary to decreased fetal mobility following environmental/genetic abnormalities. BICD2 pathogenic variants have been associated with autosomal dominant spinal muscular atrophy with lower extremity predominance (SMALED2). We report the case of a newborn with decreased fetal movements and ventriculomegaly diagnosed in utero, born with severe AMC, multiple bone fractures, congenital hip dislocation, and respiratory insufficiency that led to neonatal death. His mother had AMC diagnosis without established etiology. Her phenotype characterization was key to guide the genetic investigation. A BICD 2 heterozygous variant (NM_001003800.1; c.2080C > T; p. [Arg694Cys]) was detected both in the mother and the newborn. This variant had previously been reported in 3 cases, all having de novo severe SMALED-type 2B (MIM#618291) phenotype. This is the first report of this variant (p. [Arg694Cys]) presenting with an inherited, severe, and lethal phenotype associated to intrafamilial variability, suggesting a more complex phenotype-genotype correlation than previously stated.

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