scholarly journals Evaluation of genetic causes of cardiomyopathy in childhood

2015 ◽  
Vol 25 (S2) ◽  
pp. 43-50 ◽  
Author(s):  
Stephanie M. Ware

AbstractCardiomyopathy frequently has a genetic basis. In adults, mutations in genes encoding components of the sarcomere, cytoskeleton, or desmosome are frequent genetic causes of cardiomyopathy. Although children share these causes, ~30% of children have an underlying metabolic, syndromic, or neuromuscular condition causing their cardiomyopathy, making the aetiologies more diverse in children as compared with adults. Although some children present with obvious signs or symptoms of metabolic, syndromic, or neuromuscular disease, other cases may be quite subtle, requiring a high level of suspicion in order to diagnose them. In general, the younger the child, the more extensive the differential. Advantages of identifying the underlying genetic cause of cardiomyopathy in the paediatric population include confirming the diagnosis in ambiguous cases, facilitating appropriate surveillance and management of cardiac and extra-cardiac diseases, providing prognostic information, and establishing the genetic basis in the family, thereby allowing the identification of at-risk relatives and institution of appropriate family screening as indicated. For these reasons, genetic testing is increasingly recognised as standard of care, and guidelines for genetic counselling, testing, and incorporation of family-based risk assessment have been established. Therapies aimed at treating specific genetic aetiologies of cardiomyopathy are emerging and are exciting new developments that require increasingly sophisticated approaches to diagnosis. As genetic testing capabilities continue to expand technically, careful interpretation, knowledgeable clinical utilisation, and appropriate dissemination of genetic information are important and challenging components of clinical care.

2021 ◽  
Vol 128 (10) ◽  
pp. 1533-1553
Author(s):  
A.J. Marian

Hypertrophic cardiomyopathy (HCM) is a genetic disease of the myocardium characterized by a hypertrophic left ventricle with a preserved or increased ejection fraction. Cardiac hypertrophy is often asymmetrical, which is associated with left ventricular outflow tract obstruction. Myocyte hypertrophy, disarray, and myocardial fibrosis constitute the histological features of HCM. HCM is a relatively benign disease but an important cause of sudden cardiac death in the young and heart failure in the elderly. Pathogenic variants (PVs) in genes encoding protein constituents of the sarcomeres are the main causes of HCM. PVs exhibit a gradient of effect sizes, as reflected in their penetrance and variable phenotypic expression of HCM. MYH7 and MYBPC3 , encoding β-myosin heavy chain and myosin binding protein C, respectively, are the two most common causal genes and responsible for ≈40% of all HCM cases but a higher percentage of HCM in large families. PVs in genes encoding protein components of the thin filaments are responsible for ≈5% of the HCM cases. Whereas pathogenicity of the genetic variants in large families has been firmly established, ascertainment causality of the PVs in small families and sporadic cases is challenging. In the latter category, PVs are best considered as probabilistic determinants of HCM. Deciphering the genetic basis of HCM has enabled routine genetic testing and has partially elucidated the underpinning mechanism of HCM as increased number of the myosin molecules that are strongly bound to actin. The discoveries have led to the development of mavacamten that targets binding of the myosin molecule to actin filaments and imparts beneficial clinical effects. In the coming years, the yield of the genetic testing is expected to be improved and the so-called missing causal gene be identified. The advances are also expected to enable development of additional specific therapies and editing of the mutations in HCM.


2020 ◽  
Vol 29 (4) ◽  
pp. 738-761
Author(s):  
Tess K. Koerner ◽  
Melissa A. Papesh ◽  
Frederick J. Gallun

Purpose A questionnaire survey was conducted to collect information from clinical audiologists about rehabilitation options for adult patients who report significant auditory difficulties despite having normal or near-normal hearing sensitivity. This work aimed to provide more information about what audiologists are currently doing in the clinic to manage auditory difficulties in this patient population and their views on the efficacy of recommended rehabilitation methods. Method A questionnaire survey containing multiple-choice and open-ended questions was developed and disseminated online. Invitations to participate were delivered via e-mail listservs and through business cards provided at annual audiology conferences. All responses were anonymous at the time of data collection. Results Responses were collected from 209 participants. The majority of participants reported seeing at least one normal-hearing patient per month who reported significant communication difficulties. However, few respondents indicated that their location had specific protocols for the treatment of these patients. Counseling was reported as the most frequent rehabilitation method, but results revealed that audiologists across various work settings are also successfully starting to fit patients with mild-gain hearing aids. Responses indicated that patient compliance with computer-based auditory training methods was regarded as low, with patients generally preferring device-based rehabilitation options. Conclusions Results from this questionnaire survey strongly suggest that audiologists frequently see normal-hearing patients who report auditory difficulties, but that few clinicians are equipped with established protocols for diagnosis and management. While many feel that mild-gain hearing aids provide considerable benefit for these patients, very little research has been conducted to date to support the use of hearing aids or other rehabilitation options for this unique patient population. This study reveals the critical need for additional research to establish evidence-based practice guidelines that will empower clinicians to provide a high level of clinical care and effective rehabilitation strategies to these patients.


Genetics ◽  
2001 ◽  
Vol 159 (4) ◽  
pp. 1765-1778
Author(s):  
Gregory J Budziszewski ◽  
Sharon Potter Lewis ◽  
Lyn Wegrich Glover ◽  
Jennifer Reineke ◽  
Gary Jones ◽  
...  

Abstract We have undertaken a large-scale genetic screen to identify genes with a seedling-lethal mutant phenotype. From screening ~38,000 insertional mutant lines, we identified >500 seedling-lethal mutants, completed cosegregation analysis of the insertion and the lethal phenotype for >200 mutants, molecularly characterized 54 mutants, and provided a detailed description for 22 of them. Most of the seedling-lethal mutants seem to affect chloroplast function because they display altered pigmentation and affect genes encoding proteins predicted to have chloroplast localization. Although a high level of functional redundancy in Arabidopsis might be expected because 65% of genes are members of gene families, we found that 41% of the essential genes found in this study are members of Arabidopsis gene families. In addition, we isolated several interesting classes of mutants and genes. We found three mutants in the recently discovered nonmevalonate isoprenoid biosynthetic pathway and mutants disrupting genes similar to Tic40 and tatC, which are likely to be involved in chloroplast protein translocation. Finally, we directly compared T-DNA and Ac/Ds transposon mutagenesis methods in Arabidopsis on a genome scale. In each population, we found only about one-third of the insertion mutations cosegregated with a mutant phenotype.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Bryn D. Webb ◽  
Irini Manoli ◽  
Elizabeth C. Engle ◽  
Ethylin W. Jabs

AbstractThere is a broad differential for patients presenting with congenital facial weakness, and initial misdiagnosis unfortunately is common for this phenotypic presentation. Here we present a framework to guide evaluation of patients with congenital facial weakness disorders to enable accurate diagnosis. The core categories of causes of congenital facial weakness include: neurogenic, neuromuscular junction, myopathic, and other. This diagnostic algorithm is presented, and physical exam considerations, additional follow-up studies and/or consultations, and appropriate genetic testing are discussed in detail. This framework should enable clinical geneticists, neurologists, and other rare disease specialists to feel prepared when encountering this patient population and guide diagnosis, genetic counseling, and clinical care.


2019 ◽  
Vol 11 (3) ◽  
pp. 954-969 ◽  
Author(s):  
Yann Dussert ◽  
Isabelle D Mazet ◽  
Carole Couture ◽  
Jérôme Gouzy ◽  
Marie-Christine Piron ◽  
...  

Abstract Downy mildews are obligate biotrophic oomycete pathogens that cause devastating plant diseases on economically important crops. Plasmopara viticola is the causal agent of grapevine downy mildew, a major disease in vineyards worldwide. We sequenced the genome of Pl. viticola with PacBio long reads and obtained a new 92.94 Mb assembly with high contiguity (359 scaffolds for a N50 of 706.5 kb) due to a better resolution of repeat regions. This assembly presented a high level of gene completeness, recovering 1,592 genes encoding secreted proteins involved in plant–pathogen interactions. Plasmopara viticola had a two-speed genome architecture, with secreted protein-encoding genes preferentially located in gene-sparse, repeat-rich regions and evolving rapidly, as indicated by pairwise dN/dS values. We also used short reads to assemble the genome of Plasmopara muralis, a closely related species infecting grape ivy (Parthenocissus tricuspidata). The lineage-specific proteins identified by comparative genomics analysis included a large proportion of RxLR cytoplasmic effectors and, more generally, genes with high dN/dS values. We identified 270 candidate genes under positive selection, including several genes encoding transporters and components of the RNA machinery potentially involved in host specialization. Finally, the Pl. viticola genome assembly generated here will allow the development of robust population genomics approaches for investigating the mechanisms involved in adaptation to biotic and abiotic selective pressures in this species.


2012 ◽  
Vol 33 (07) ◽  
pp. 649-656 ◽  
Author(s):  
Mark Holodniy ◽  
Gina Oda ◽  
Patricia L. Schirmer ◽  
Cynthia A. Lucero ◽  
Yury E. Khudyakov ◽  
...  

Objective.To determine whether improper high-level disinfection practices during endoscopy procedures resulted in bloodborne viral infection transmission.Design.Retrospective cohort study.Setting.Four Veterans Affairs medical centers (VAMCs).Patients.Veterans who underwent colonoscopy and laryngoscopy (ear, nose, and throat [ENT]) procedures from 2003 to 2009.Methods.Patients were identified through electronic health record searches and serotested for human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV). Newly discovered case patients were linked to a potential source with known identical infection, whose procedure occurred no more than 1 day prior to the case patient's procedure. Viral genetic testing was performed for case/proximate pairs to determine relatedness.Results.Of 10,737 veterans who underwent endoscopy at 4 VAMCs, 9,879 patients agreed to viral testing. Of these, 90 patients were newly diagnosed with 1 or more viral bloodborne pathogens (BBPs). There were no case/proximate pairings found for patients with either HIV or HBV; 24 HCV case/proximate pairings were found, of which 7 case patients and 8 proximate patients had sufficient viral load for further genetic testing. Only 2 of these cases, both of whom underwent laryngoscopy, and their 4 proximates agreed to further testing. None of the 4 remaining proximate patients who underwent colonoscopy agreed to further testing. Mean genetic distance between the 2 case patients and 4 proximate patients ranged from 13.5% to 19.1%.Conclusions.Our investigation revealed that exposure to improperly reprocessed ENT endoscopes did not result in viral transmission in those patients who had viral genetic analysis performed. Any potential transmission of BBPs from colonoscopy remains unknown.


2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Peng Chen ◽  
Hongyang Jing ◽  
Mingtao Xiong ◽  
Qian Zhang ◽  
Dong Lin ◽  
...  

AbstractThe genes encoding for neuregulin1 (NRG1), a growth factor, and its receptor ErbB4 are both risk factors of major depression disorder and schizophrenia (SZ). They have been implicated in neural development and synaptic plasticity. However, exactly how NRG1 variations lead to SZ remains unclear. Indeed, NRG1 levels are increased in postmortem brain tissues of patients with brain disorders. Here, we studied the effects of high-level NRG1 on dendritic spine development and function. We showed that spine density in the prefrontal cortex and hippocampus was reduced in mice (ctoNrg1) that overexpressed NRG1 in neurons. The frequency of miniature excitatory postsynaptic currents (mEPSCs) was reduced in both brain regions of ctoNrg1 mice. High expression of NRG1 activated LIMK1 and increased cofilin phosphorylation in postsynaptic densities. Spine reduction was attenuated by inhibiting LIMK1 or blocking the NRG1–LIMK1 interaction, or by restoring NRG1 protein level. These results indicate that a normal NRG1 protein level is necessary for spine homeostasis and suggest a pathophysiological mechanism of abnormal spines in relevant brain disorders.


1999 ◽  
Vol 12 (3) ◽  
pp. 182-188 ◽  
Author(s):  
Lorenz Bülow ◽  
Uwe Köhler ◽  
Rüdiger Cerff ◽  
Reinhard Hehl ◽  
Klaus Düring

The induction pattern of the GapC4 promoter from maize in transgenic potato has been analyzed by fusion to the β-glucuronidase (gus) gene. Under anaerobic conditions this promoter confers high level expression not only in leaves, stems, and roots but also in tubers. After inoculation of potato tuber disks with Erwinia carotovora subsp. atroseptica, β-glucuronidase (GUS) activity could be detected in macerated tissue as well as in surrounding intact tissue. In mock controls no induction was detected, ruling out any induction due to an overall limitation in oxygen in the experimental system. In addition, it could be proven that no diffusion of GUS protein from macerated into intact tissue occurred. The promoter was shown to be aerobically induced even in the absence of live bacteria by incubation with purified Erwinia spp. pectolytic enzymes alone. Therefore, promoter induction seems to be mediated by a mobile factor instead of by limitation in oxygen. These results demonstrate that the maize GapC4 promoter is suitable for directing foreign genes encoding antibacterial proteins in transgenic potato.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Reema Harrison ◽  
Madhav Raman ◽  
Ramesh Lahiru Walpola ◽  
Ashfaq Chauhan ◽  
Ursula M. Sansom-Daly

Abstract Background Family-based ‘informal’ caregivers are critical to enable sustainable cancer care that produces optimal health outcomes but also gives rise to psychological burdens on caregivers. Evidence of psychosocial support for caregivers does not currently address the impacts of their role in providing clinical and health-related care for their loved ones. The present study sought to address this gap including with those from priority populations. Methods Qualitative data was collected using focus group and interview methods. We purposively sampled caregivers identified as having a high burden of responsibility for providing clinical care including those from ethnic minority backgrounds, parental caregivers and those living rurally. Transcripts were subject to thematic analysis utilising a team-based approach. Results Family-based caregivers included spouses (11), parents (7), children (1), siblings (1). Ten participants were from ethnic minority backgrounds and five participants were from regional or rural locations. Four resulting inter-related themes were; 1) Dual burden of providing clinical care and managing personal emotional distress; 2) Navigating healthcare partnership dynamics; 3) Developing a caregiving skillset, and 4) Unique supportive needs and barriers to access. These data provide evidence of the unique challenge of providing clinical care as part of family-based caregiving for a loved one with cancer, and the absence of support for caregivers to take up this role. Conclusion Our findings highlight the substantial contribution of family-based caregivers to the provision of cancer care in contemporary health systems. Inadequate support for caregivers is apparent with regard to their role in providing clinical aspects of care such as medication administration and management. Support programs to prepare caregivers to provide clinical care while building capacity to manage their stressors and emotions through this challenging period may be valuable towards sustainable, person-centred care.


Author(s):  
Courtney Berrios ◽  
Emily A. Hurley ◽  
Laurel Willig ◽  
Isabelle Thiffault ◽  
Carol Saunders ◽  
...  

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