scholarly journals A NOTCH3 homozygous nonsense mutation in familial Sneddon syndrome with pediatric stroke

Author(s):  
Elli Katharine Greisenegger ◽  
Sara Llufriu ◽  
Angel Chamorro ◽  
Alvaro Cervera ◽  
Adriano Jimenez-Escrig ◽  
...  

Abstract Sneddon syndrome is a rare disorder affecting small and medium-sized blood vessels that is characterized by the association of livedo reticularis and stroke. We performed whole-exome sequencing (WES) in 2 affected siblings of a consanguineous family with childhood-onset stroke and identified a homozygous nonsense mutation within the epidermal growth factor repeat (EGFr) 19 of NOTCH3, p.(Arg735Ter). WES of 6 additional cases with adult-onset stroke revealed 2 patients carrying heterozygous loss-of-function variants in putative NOTCH3 downstream genes, ANGPTL4, and PALLD. Our findings suggest that impaired NOTCH3 signaling is one underlying disease mechanism and that bi-allelic loss-of-function mutation in NOTCH3 is a cause of familial Sneddon syndrome with pediatric stroke.

2016 ◽  
Author(s):  
Laura S Kremer ◽  
Daniel M Bader ◽  
Christian Mertes ◽  
Robert Kopajtich ◽  
Garwin Pichler ◽  
...  

AbstractAcross a large variety of Mendelian disorders, ~50-75% of patients do not receive a genetic diagnosis by whole exome sequencing indicative of underlying disease-causing variants in non-coding regions. In contrast, whole genome sequencing facilitates the discovery of all genetic variants, but their sizeable number, coupled with a poor understanding of the non-coding genome, makes their prioritization challenging. Here, we demonstrate the power of transcriptome sequencing to provide a confirmed genetic diagnosis for 10% (5 of 48) of undiagnosed mitochondrial disease patients and identify strong candidate genes for patients remaining without diagnosis. We found a median of 1 aberrantly expressed gene, 5 aberrant splicing events, and 6 mono-allelically expressed rare variants in patient-derived fibroblasts and established disease-causing roles for each kind. Private exons often arose from sites that are weakly spliced in other individuals, providing an important clue for future variant prioritization. One such intronic exon-creating variant was found in three unrelated families in the complex I assembly factor TIMMDC1, which we consequently established as a novel disease-associated gene. In conclusion, our study expands the diagnostic tools for detecting non-exonic variants of Mendelian disorders and provides examples of intronic loss-of-function variants with pathological relevance.


2020 ◽  
Vol 36 (6) ◽  
Author(s):  
Muhammad Imran Naseer ◽  
Angham Abdulrahman Abdulkareem ◽  
Mohammed Mohammed Jan ◽  
Adeel G. Chaudhary ◽  
Mohammad H. Al-Qahtani

Objective: To study the causative variants in affected member of a Saudi family with Tay-Sachs disorder. This disorder includes paralysis, decreasing in attentiveness, seizures, blindness, motor deterioration progresses rapidly leading to a completely unresponsive state and a cherry-red spot visible on the eye. Methods: Whole exome sequencing (WES) and Sanger sequencing was performed to study the variant leading to the disease. Results: WES data analysis and Sanger sequencing validation, identifies a homozygous nonsense mutation c.1177C>T, p.Arg393Ter as a result in protein change. This mutation was also studied in 100 unrelated healthy controls. Conclusions: We detected homozygous mutation in HEXA gene that may lead to cause Tay-Sachs disorder. Moreover, explain the possibility that HEXA gene may play important role for multiple aspects of normal human neurodevelopment. doi: https://doi.org/10.12669/pjms.36.6.2579 How to cite this:Naseer MI, Abdulkareem AA, Jan MM, Chaudhary AG, Al-Qahtani MH. Whole exome sequencing reveals a homozygous nonsense mutation in HEXA gene leading to Tay-Sachs disease in Saudi Family. Pak J Med Sci. 2020;36(6):---------.  doi: https://doi.org/10.12669/pjms.36.6.2579 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


2019 ◽  
Author(s):  
Jiang Liu ◽  
Da Liu ◽  
Muzheng Li ◽  
Keke Wu ◽  
Na Liu ◽  
...  

Abstract Background Cardiac conduction disease(CCD) and dilated cardiomyopathy(DCM) are two common cardiovascular diseases which can lead to life-threatening conditions. The importance of heredity in these two diseases has been realized in recent years. Several casual genes have been found to be implicated in CCD and DCM such as LMNA,SCN5A,TTN,TNNI3K and so on. Rare genetic mutations in TNNI3K have been identified to be in connection with CCD and DCM.Methods Next generation sequencing(NGS) was carried out in order to identify the underlying disease-causing mutation in a Chinese family with CCD and DCM. The mutations were validated by Sanger sequencing.Results A nonsense mutation in TNNI3K(NM_015978.2: g.170891C>T,c.1441C>T) was identified in this family and validated by Sanger sequencing.Conclusions This study described a Chinese family with CCD and DCM caused by a nonsense TNNI3K mutation.TNNI3K harboring the mutation(c.1441C>T) possibly implicated a loss-of-function pathogenic mechanism with an autosomal dominant inheritance pattern. This research enriches the phenotypic spectrum of TNNI3K mutations, casting a new light upon the genotype-phenotype correlations between TNNI3K mutations and cardiovascular diseases.


Author(s):  
Yousef Binamer ◽  
Muzamil A. Chisti

AbstractKindler syndrome (KS) is a rare photosensitivity disorder with autosomal recessive mode of inheritance. It is characterized by acral blistering in infancy and childhood, progressive poikiloderma, skin atrophy, abnormal photosensitivity, and gingival fragility. Besides these major features, many minor presentations have also been reported in the literature. We are reporting two cases with atypical features of the syndrome and a new feature of recurrent neutropenia. Whole exome sequencing analysis was done using next-generation sequencing which detected a homozygous loss-of-function (LOF) variant of FERMT1 in both patients. The variant is classified as a pathogenic variant as per the American College of Medical Genetics and Genomics guidelines. Homozygous LOF variants of FERMT1 are a common mechanism of KS and as such confirm the diagnosis of KS in our patients even though the presentation was atypical.


2020 ◽  
Vol 22 (10) ◽  
pp. 675-682 ◽  
Author(s):  
Jie Yin ◽  
Zhongping Qin ◽  
Kai Wu ◽  
Yufei Zhu ◽  
Landian Hu ◽  
...  

Backgrounds and Objective: Blue rubber bleb nevus syndrome (BRBN) or Bean syndrome is a rare Venous Malformation (VM)-associated disorder, which mostly affects the skin and gastrointestinal tract in early childhood. Somatic mutations in TEK have been identified from BRBN patients; however, the etiology of TEK mutation-negative patients of BRBN need further investigation. Method: Two unrelated sporadic BRBNs and one sporadic VM were firstly screened for any rare nonsilent mutation in TEK by Sanger sequencing and subsequently applied to whole-exome sequencing to identify underlying disease causative variants. Overexpression assay and immunoblotting were used to evaluate the functional effect of the candidate disease causative variants. Results: In the VM case, we identified the known causative somatic mutation in the TEK gene c.2740C>T (p.Leu914Phe). In the BRBN patients, we identified two rare germline variants in GLMN gene c.761C>G (p.Pro254Arg) and c.1630G>T(p.Glu544*). The GLMN-P254R-expressing and GLMN-E544X-expressing HUVECs exhibited increased phosphorylation of mTOR-Ser-2448 in comparison with GLMN-WTexpressing HUVECs in vitro. Conclusion: Our results demonstrated that rare germline variants in GLMN might contribute to the pathogenesis of BRBN. Moreover, abnormal mTOR signaling might be the pathogenesis mechanism underlying the dysfunction of GLMN protein.


2019 ◽  
Vol 19 (9) ◽  
pp. 683-687 ◽  
Author(s):  
Tawfiq Froukh ◽  
Ammar Hawwari

Background: Keratoconus (KC) is usually bilateral, noninflammatory progressive corneal ectasia in which the cornea becomes progressively thin and conical. Despite the strong evidence of genetic contribution in KC, the etiology of KC is not understood in most cases. Methods: In this study, we used whole-exome sequencing to identify the genetic cause of KC in two sibs in a consanguineous family. The Homozygous frameshift variant NM_001253826.1:c.60delC;p.Leu21Cysfs*6 was identified in the gene Nacetylgalactosaminyltransferase 14 (GALNT14). The variant does not exist in all public databases neither in our internal exome database. Moreover, no database harbours homozygous loss of function variants in the candidate gene. Result: GALNT14 catalyses the initial reaction in O-linked oligosaccharide biosynthesis, the transfer of an N-acetyl-D- galactosamine residue to a serine or threonine residue on target proteins especially Mucins. Conclusion: As alterations of mucin’s glycosylation are linked to a number of eye diseases, we demonstrate in this study an association between the truncated protein GALNT14 and KC.


2021 ◽  
Vol 49 (4) ◽  
pp. 030006052110059
Author(s):  
Xinwen Zhang ◽  
Shaozhi Zhao ◽  
Hongwei Liu ◽  
Xiaoyan Wang ◽  
Xiaolei Wang ◽  
...  

Fucosidosis is a rare lysosomal storage disorder characterized by deficiency of α-L-fucosidase with an autosomal recessive mode of inheritance. Here, we describe a 4-year-old Chinese boy with signs and symptoms of fucosidosis but his parents were phenotypically normal. Whole exome sequencing (WES) identified a novel homozygous single nucleotide deletion (c.82delG) in the exon 1 of the FUCA1 gene. This mutation will lead to a frameshift which will result in the formation of a truncated FUCA1 protein (p.Val28Cysfs*105) of 132 amino acids approximately one-third the size of the wild type FUCA1 protein (466 amino acids). Both parents were carrying the mutation in a heterozygous state. This study expands the mutational spectrum of the FUCA1 gene associated with fucosidosis and emphasises the benefits of WES for accurate and timely clinical diagnosis of this rare disease.


Author(s):  
Johann Kaspar Lieberwirth ◽  
Pascal Joset ◽  
Anja Heinze ◽  
Julia Hentschel ◽  
Anja Stein ◽  
...  

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1790.2-1790
Author(s):  
R. M. Alcobendas ◽  
C. Quintana ◽  
J. Arostegui ◽  
C. Udaondo ◽  
S. Murias Loza ◽  
...  

Background:Few patients have been described in the literature with mutations in the Lacasa Domain containing one (LACC1) gene. Its clinical presentation usually associates sustained systemic inflammation associated with chronic polyarticular erosive arthritis. Until now, there have been multiple treatments described to try to control the disease, however, they are generally unsuccessful in the long term.Objectives:Describe the clinical course of a patient as well as the different treatments usedMethods:Clinical chart reviewResults:Female 18-year-old born from a consanguineous Moroccan couple. Mother, brother and sister with similar conditions. She started at 3 years with fever, anemia, intense elevation of acute phase reactants and symmetric polyarthritis (knees, elbows, carps, shoulders, hands and ankles). Subsequent whole exome sequencing identified c.128_129delGT mutation in the LACC1/FAMIN gene. During the course of her illness, she has received treatment with oral, intravenous and infiltrated corticosteroid, methotrexate and etanercept, without getting adequate control of the disease. In 2016, she started treatment with tocilizumab (8 mg / kg every two weeks), obtaining an acceptable control of the disease (requiring periodic infiltrations every 2-3 months due to persistent arthritis). Nonetheless, in April 2019, she consulted for clinical worsening of the arthritis and laboratory test (C reactive protein 99.7 mg / L, erythrosedimentation rate 53 mm / h, leukocytes 13,500/µL and neutrophils 10,930/µL). At that time, she discontinued therapy with tocilizumab and started tofacitinib 5 mg every 12 hours with good evolution. Since its introduction, it has not required joint infiltration again and the inflammatory parameters (persistently elevated previously) have normalized.Conclusion:The jak kinasa inhibitors may be a treatment option in those patients with bad response to conventional therapy.References:[1]Rabionet R, Remesal A, Mensa-Vilaró A, Murías S, Alcobendas R, González-Roca E, Ruiz-Ortiz E, Antón J, Iglesias E, Modesto C, Comas D, Puig A, Drechsel O, Ossowski S, Yagüe J, Merino R, Estivill X, Arostegui JI. Biallelic loss-of-function LACC1/FAMIN Mutations Presenting as Rheumatoid Factor-Negative Polyarticular Juvenile Idiopathic Arthritis. Sci Rep. 2019 Mar 14;9(1):4579Disclosure of Interests:None declared


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