scholarly journals A nonsense variant in FBN1 caused autosomal dominant Marfan syndrome in a Chinese family: a case report

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuping Niu ◽  
Sexin Huang ◽  
Zeyu Wang ◽  
Peiwen Xu ◽  
Lijuan Wang ◽  
...  
Keyword(s):  
Real Time ◽  
Marfan Syndrome ◽  
Quantitative Pcr ◽  
Autosomal Dominant ◽  
Clinical Symptoms ◽  
Stop Codon ◽  
Main Pulmonary Artery ◽  
Left Ventricular ◽  
Occurrence Rate ◽  
Chinese Family

Abstract Background Marfan syndrome (MFS) is a common autosomal dominant inherited disease, and the occurrence rate is around 0.1–0.2‰. The causative variant of FNB1 gene accounts for approximately 70–80% of all MFS cases. In this study, we found a heterozygous c.3217G > T (p.Glu1073*) nonsense variant in the FBN1 gene. This finding extended the variant spectrum of the FBN1 gene and will provide a solution for patients to bear healthy offspring by preimplantation genetic testing or prenatal diagnosis. Case presentation The patient was treated due to tachycardia during excitement in a hospital. Echocardiography showed dilatation of the ascending aorta and main pulmonary artery, mitral regurgitation (mild), tricuspid regurgitation (mild), and abnormal left ventricular filling. Electrocardiograph showed sinus rhythm. In addition, flutters of shadows in front of his eyes and vitreous opacity were present in the patient. Genomic DNA was extracted from peripheral blood samples from members of the family and 100 unrelated controls. Potential variants were screened out by next-generation sequencing and confirmed by MLPA & Sanger sequencing. Real-time fluorescence quantitative PCR (RT-qPCR) was performed to detect the relative mRNA quantitation in the patient. A heterozygous nonsense variant c.3217G > T of the FBN1 gene, which resulted in p. Glu1073Term, was identified in both patients. Only wild type bases were found in the cDNA sequence of the patient. Real-time fluorogenic quantitative PCR results showed that the relative expression level of FBN1 cDNA in the patient was only about 21% compared to that of normal individuals. This variant c.3217G > T of the FBN1 gene introduces a Stop codon in the cb-EGF12 domain. We speculated that a premature translational-termination codon (PTC) was located in the mRNA and the target mRNA was disintegrated through a process known as nonsense-mediated mRNA decay (NMD), which led to a significant decrease of the fibrillin-1 protein, eventually causing clinical symptoms in the patient. Conclusions In this study, we found a heterozygous c.3217G > T (p.Glu1073*) nonsense variant in the FBN1 gene, which eventually led to Marfan syndrome in a Chinese family.

Magnetic resonance imaging of progressive cardiomyopathic changes in the db/db mouse

2007 ◽  
Vol 292 (5) ◽  
pp. H2106-H2118 ◽  
Author(s):  
Patrick Yue ◽  
Takayasu Arai ◽  
Masahiro Terashima ◽  
Ahmad Y. Sheikh ◽  
Feng Cao ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Real Time ◽  
Quantitative Pcr ◽  
Wall Thickness ◽  
Left Ventricular ◽  
Metabolic Imaging ◽  
Contractile Dysfunction ◽  
Functional Changes ◽  
Real Time Quantitative Pcr ◽  
End Diastolic Volume

The db/db mouse is a well-established model of diabetes. Previous reports have documented contractile dysfunction (i.e., cardiomyopathy) in these animals, although the extant literature provides limited insights into cardiac structure and function as they change over time. To better elucidate the natural history of cardiomyopathy in db/db mice, we performed cardiac magnetic resonance (CMR) scans on these animals. CMR imaging was conducted with a 4.7-T magnet on female db/db mice and control db/+ littermates at 5, 9, 13, 17, and 22 wk of age. Gated gradient echo sequences were used to obtain cineographic short-axis slices from apex to base. From these images left ventricular (LV) mass (LVM), wall thickness, end-diastolic volume (LVEDV), and ejection fraction (LVEF) were determined. Additionally, cardiac [18F]fluorodeoxyglucose ([18F]FDG) PET scanning, pressure-volume loops, and real-time quantitative PCR on db/db myocardium were performed. Relative to control, db/db mice developed significant increases in LVM and wall thickness as early as 9 wk of age. LVEDV diverged slightly later, at 13 wk. Interestingly, compared with the baseline level, LVEF in the db/db group did not decrease significantly until 22 wk. Additionally, [18F]FDG metabolic imaging showed a 40% decrease in glucose uptake in db/db mice. Furthermore, contractile dysfunction was observed in 15-wk db/db mice undergoing pressure-volume loops. Finally, real-time quantitative PCR revealed an age-dependent recapitulation of the fetal gene program, consistent with a myopathic process. In summary, as assessed by CMR, db/db mice develop characteristic structural and functional changes consistent with cardiomyopathy.

scholarly journals A Novel Nonsense Mutation ofPOU4F3Gene Causes Autosomal Dominant Hearing Loss

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Chi Zhang ◽  
Mingming Wang ◽  
Yun Xiao ◽  
Fengguo Zhang ◽  
Yicui Zhou ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Nonsense Mutation ◽  
Autosomal Dominant ◽  
Late Onset ◽  
Stop Codon ◽  
Novel Mutation ◽  
Genetic Diagnosis ◽  
Chinese Family ◽  
Nonsyndromic Hearing Loss ◽  
Truncated Protein

POU4F3gene encodes a transcription factor which plays an essential role in the maturation and maintenance of hair cells in cochlea and vestibular system. Several mutations ofPOU4F3have been reported to cause autosomal dominant nonsyndromic hearing loss in recent years. In this study, we describe a pathogenic nonsense mutation located inPOU4F3in a four-generation Chinese family. Target region capture sequencing was performed to search for the candidate mutations from 81 genes related to nonsyndromic hearing loss in this family. A novel nonsense mutation ofPOU4F3, c.337C>T (p.Gln113⁎), was identified in a Chinese family characterized by late-onset progressive nonsyndromic hearing loss. The novel mutation cosegregated with hearing loss in this family and was absent in 200 ethnicity-matched controls. The mutation led to a stop codon and thus a truncated protein with no functional domains remained. Transient transfection and immunofluorescence assay revealed that the subcellular localization of the truncated protein differed markedly from normal protein, which could be the underlying reason for complete loss of its normal function. Here, we report the first nonsense mutation ofPOU4F3associated with progressive hearing loss and explored the possible underlying mechanism. Routine examination ofPOU4F3is necessary for the genetic diagnosis of hereditary hearing loss in the future.

scholarly journals A novel FBN1 heterozygous mutation identified in a Chinese family with autosomal dominant Marfan syndrome

2015 ◽  
Vol 14 (2) ◽  
pp. 4125-4132 ◽  
Author(s):  
Y. Yin ◽  
X.-H. Liu ◽  
X.-H. Li ◽  
N. Fan ◽  
D.-F. Lei ◽  
...  
Keyword(s):  
Marfan Syndrome ◽  
Autosomal Dominant ◽  
Chinese Family ◽  
Heterozygous Mutation

scholarly journals A Novel Truncating Mutation in HOMER2 Causes Nonsyndromic Progressive DFNA68 Hearing Loss in a Spanish Family

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 411
Author(s):  
María Lachgar ◽  
Matías Morín ◽  
Manuela Villamar ◽  
Ignacio del Castillo ◽  
Miguel Ángel Moreno-Pelayo
Keyword(s):  
Hearing Loss ◽  
Stop Codon ◽  
Coiled Coil ◽  
Premature Stop Codon ◽  
Scaffolding Protein ◽  
Common Mechanism ◽  
Chinese Family ◽  
Truncating Mutation ◽  
Spanish Family ◽  
Sensory Defect

Nonsyndromic hereditary hearing loss is a common sensory defect in humans that is clinically and genetically highly heterogeneous. So far, 122 genes have been associated with this disorder and 50 of them have been linked to autosomal dominant (DFNA) forms like DFNA68, a rare subtype of hearing impairment caused by disruption of a stereociliary scaffolding protein (HOMER2) that is essential for normal hearing in humans and mice. In this study, we report a novel HOMER2 variant (c.832_836delCCTCA) identified in a Spanish family by using a custom NGS targeted gene panel (OTO-NGS-v2). This frameshift mutation produces a premature stop codon that may lead in the absence of NMD to a shorter variant (p.Pro278Alafs*10) that truncates HOMER2 at the CDC42 binding domain (CBD) of the coiled-coil structure, a region that is essential for protein multimerization and HOMER2-CDC42 interaction. c.832_836delCCTCA mutation is placed close to the previously identified c.840_840dup mutation found in a Chinese family that truncates the protein (p.Met281Hisfs*9) at the CBD. Functional assessment of the Chinese mutant revealed decreased protein stability, reduced ability to multimerize, and altered distribution pattern in transfected cells when compared with wild-type HOMER2. Interestingly, the Spanish and Chinese frameshift mutations might exert a similar effect at the protein level, leading to truncated mutants with the same Ct aberrant protein tail, thus suggesting that they can share a common mechanism of pathogenesis. Indeed, age-matched patients in both families display quite similar hearing loss phenotypes consisting of early-onset, moderate-to-profound progressive hearing loss. In summary, we have identified the third variant in HOMER2, which is the first one identified in the Spanish population, thus contributing to expanding the mutational spectrum of this gene in other populations, and also to clarifying the genotype–phenotype correlations of DFNA68 hearing loss.

scholarly journals INF2 p.Arg214Cys mutation in a Chinese family with rapidly progressive renal failure and follow-up of renal transplantation: case report and literature review

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Wenbo Zhao ◽  
Xinxin Ma ◽  
Xiaohao Zhang ◽  
Dan Luo ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Renal Failure ◽  
Renal Disease ◽  
Autosomal Dominant ◽  
Mutational Analysis ◽  
Elevated Serum ◽  
Chinese Family ◽  
Progressive Renal Failure ◽  
Rapidly Progressive Renal Failure ◽  
Stage Renal Disease ◽  
End Stage

Abstract Background Heterozygous mutations in the inverted formin 2 (INF2) gene are related to secondary focal segmental glomerulosclerosis (FSGS), a rare secondary disease associated with rapidly progressive renal failure. Case presentation We report a patient with familial autosomal INF2 mutation manifesting nephritic syndromes and elevated serum creatinine levels. Mutational analysis revealed an autosomal dominant (AD) inheritance pattern and a mutation in exon 4 (p.Arg214Cys) of INF2 as the likely cause, which has not been previously described in an Asian family. The patient progressed to end-stage renal disease (ESRD) and received hemodialysis. His mother had undergone renal transplant 3 years earlier, and his grandmother had carried the p.Arg214Cys mutation for more than 80 years without any sign of renal dysfunction. Conclusions This is the first report to identify an association between a familial autosomal dominant INF2 p.Arg214Cys mutation and rapidly progressive renal disease in an Asian family. INF2 mutation analysis should not be restricted to individuals without family history of FSGS, rather it should also be performed on individuals for whom drug-based therapies are not effective. In this case, kidney transplant is an effective alternative.

scholarly journals A Novel Mutation in COL4A1 Gene in a Chinese Family with Pontine Autosomal Dominant Microangiopathy and Leukoencephalopathy

2021 ◽  
Author(s):  
Qing Li ◽  
Chengfeng Wang ◽  
Wei Li ◽  
Zaiqiang Zhang ◽  
Shanshan Wang ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Skin Biopsy ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Autosomal Dominant ◽  
Chinese Family ◽  
Heterozygous Mutation ◽  
Collagen Type Iv ◽  
Lacunar Infarcts ◽  
Whole Exome

AbstractPontine autosomal dominant microangiopathy and leukoencephalopathy (PADMAL) is a rare hereditary cerebral small vessel disease. We report a novel collagen type IV alpha 1 (COL4A1) gene mutation in a Chinese family with PADMAL. The index case was followed up for 6 years. Neuroimaging, whole-exome sequencing, skin biopsy, and pedigree analysis were performed. She initially presented with minor head injury at age 38. MRI brain showed chronic lacunar infarcts in the pons, left thalamus, and right centrum semiovale. Extensive workup was unremarkable except for a patent foramen ovale (PFO). Despite anticoagulation, PFO closure, and antiplatelet therapy, the patient had recurrent lacunar infarcts in the pons and deep white matter, as well as subcortical microhemorrhages. Whole-exome sequencing demonstrated a novel c.*34G > T mutation in the 3′ untranslated region of COL4A1 gene. Skin biopsy subsequently demonstrated thickening of vascular basement membrane, proliferation of endothelial cells, and stenosis of vascular lumen. Three additional family members had gene testing and 2 of them were found to have the same heterozygous mutation. Of the 18 individuals in the pedigree of 3 generations, 12 had clinical and MRI evidence of PADMAL. The mechanisms of both ischemic and hemorrhagic stroke are likely the overexpression of COLT4A1 in the basement membrane and frugality of the vessel walls. Our findings suggest that the novel c.*34G > T mutation appears to have the same functional consequences as the previously reported COL4A1 gene mutations in patients with PADMAL and multi-infarct dementia of Swedish type.

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