Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 72
Filtrar
1.
Eur J Hum Genet ; 32(7): 827-836, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38637700

RESUMO

Genetic testing can provide valuable information to mitigate personal disease risk, but the use of genetic results in life insurance underwriting is known to deter many consumers from pursuing genetic testing. In 2019, following Australian Federal Parliamentary Inquiry recommendations, the Financial Services Council (FSC) introduced an industry-led partial moratorium, prohibiting life insurance companies from using genetic test results for policies up to $AUD500,000. We used semi-structured interviews to explore genetic test consumers' experiences and views about the FSC moratorium and the use of genetic results by life insurers. Individuals who participated in an online survey and agreed to be re-contacted to discuss the issue further were invited. Interviews were 20-30-min long, conducted via video conference, transcribed verbatim and analysed using inductive content analysis. Twenty-seven participants were interviewed. Despite the moratorium, concerns about genetic discrimination in life insurance were prevalent. Participants reported instances where life insurers did not consider risk mitigation when assessing risk for policies based on genetic results, contrary to legal requirements. Most participants felt that the moratorium provided inadequate protection against discrimination, and that government legislation regulating life insurers' use of genetic results is necessary. Many participants perceived the financial limits to be inadequate, given the cost-of-living in Australia. Our findings indicate that from the perspective of participants, the moratorium has not been effective in allaying fears about genetic discrimination or ensuring adequate access to life insurance products. Concern about genetic discrimination in life insurance remains prevalent in Australia.


Assuntos
Testes Genéticos , Seguro de Vida , Humanos , Seguro de Vida/legislação & jurisprudência , Testes Genéticos/legislação & jurisprudência , Testes Genéticos/economia , Austrália , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Idoso , Pesquisa Qualitativa
2.
EClinicalMedicine ; 66: 102297, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38192593

RESUMO

Background: No previous health-economic evaluation has assessed the impact and cost-effectiveness of offering combined adult population genomic screening for mutliple high-risk conditions in a national public healthcare system. Methods: This modeling study assessed the impact of offering combined genomic screening for hereditary breast and ovarian cancer, Lynch syndrome and familial hypercholesterolaemia to all young adults in Australia, compared with the current practice of clinical criteria-based testing for each condition separately. The intervention of genomic screening, assumed as an up-front single cost in the first annual model cycle, would detect pathogenic variants in seven high-risk genes. The simulated population was 18-40 year-olds (8,324,242 individuals), modelling per-sample test costs ranging AU$100-$1200 (base-case AU$200) from the year 2023 onwards with testing uptake of 50%. Interventions for identified high-risk variant carriers follow current Australian guidelines, modelling imperfect uptake and adherence. Outcome measures were morbidity and mortality due to cancer (breast, ovarian, colorectal and endometrial) and coronary heart disease (CHD) over a lifetime horizon, from healthcare-system and societal perspectives. Outcomes included quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER), discounted 5% annually (with 3% discounting in scenario analysis). Findings: Over the population lifetime (to age 80 years), the model estimated that genomic screening per-100,000 individuals would lead to 747 QALYs gained by preventing 63 cancers, 31 CHD cases and 97 deaths. In the total model population, this would translate to 31,094 QALYs gained by preventing 2612 cancers, 542 non-fatal CHD events and 4047 total deaths. At AU$200 per-test, genomic screening would require an investment of AU$832 million for screening of 50% of the population. Our findings suggest that this intervention would be cost-effective from a healthcare-system perspective, yielding an ICER of AU$23,926 (∼£12,050/€14,110/US$15,345) per QALY gained over the status quo. In scenario analysis with 3% discounting, an ICER of AU$4758/QALY was obtained. Sensitivity analysis for the base case indicated that combined genomic screening would be cost-effective under 70% of simulations, cost-saving under 25% and not cost-effective under 5%. Threshold analysis showed that genomic screening would be cost-effective under the AU$50,000/QALY willingness-to-pay threshold at per-test costs up to AU$325 (∼£164/€192/US$208). Interpretation: Our findings suggest that offering combined genomic screening for high-risk conditions to young adults would be cost-effective in the Australian public healthcare system, at currently realistic testing costs. Other matters, including psychosocial impacts, ethical and societal issues, and implementation challenges, also need consideration. Funding: Australian Government, Department of Health, Medical Research Future Fund, Genomics Health Futures Mission (APP2009024). National Heart Foundation Future Leader Fellowship (102604).

3.
Stem Cell Res ; 63: 102829, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35728439

RESUMO

Variants in the ACTA1 gene are a common cause of nemaline myopathy (NM); a muscle disease that typically presents at birth or early childhood with hypotonia and muscle weakness. Here, we generated an induced pluripotent stem cell line (iPSC) from lymphoblastoid cells of a 3-month-old female patient with intermediate NM caused by a dominant ACTA1 variant (c.515C > A (p.Ala172Glu)). iPSCs showed typical morphology, expressed pluripotency markers, demonstrated trilineage differentiation potential, and had a normal karyotype. This line complements our previously published ACTA1 iPSC lines derived from patients with typical and severe NM.


Assuntos
Células-Tronco Pluripotentes Induzidas , Miopatias da Nemalina , Actinas/genética , Actinas/metabolismo , Pré-Escolar , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Lactente , Recém-Nascido , Músculo Esquelético/metabolismo , Mutação , Miopatias da Nemalina/genética
4.
Stem Cell Res ; 63: 102830, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35728440

RESUMO

Nemaline myopathy (NM) is a congenital skeletal muscle disorder that typically results in muscle weakness and the presence of rod-like structures (nemaline bodies) in the sarcoplasma and/or in the nuclei of myofibres. Two induced pluripotent stem cell (iPSC) lines were generated from the lymphoblastoid cells of a 1-month-old male with severe NM caused by a homozygous recessive mutation in the ACTA1 gene (c.121C > T, p.Arg39Ter). The iPSC lines demonstrated typical morphology, expressed pluripotency markers, exhibited trilineage differentiation potential and displayed a normal karyotype. These isogenic lines represent a potential resource to investigate and model recessive ACTA1 disease in a human context.


Assuntos
Células-Tronco Pluripotentes Induzidas , Miopatias da Nemalina , Actinas/genética , Actinas/metabolismo , Homozigoto , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Lactente , Masculino , Músculo Esquelético/metabolismo , Mutação , Miopatias da Nemalina/genética , Miopatias da Nemalina/metabolismo
5.
J Paediatr Child Health ; 58(2): 281-287, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34387892

RESUMO

AIM: Familial hypercholesterolaemia (FH) is a common and treatable cause of premature coronary artery disease. However, the majority of individuals with FH remain undiagnosed. This study investigated the feasibility, acceptability and cost-effectiveness of screening children aged 1-2 years for FH at the time of an immunisation. METHODS: Children 1-2 years of age were offered screening for FH with a point-of-care total cholesterol (TC) test by capillary-collected blood sample at the time of an immunisation. An additional blood sample was taken to allow genetic testing if the TC level was above the 95th percentile (>5.3 mmol/L). Parents of children diagnosed with FH were offered testing. Following detection of the affected parent, cascade testing of their first-degree blood relatives was performed. RESULTS: We screened 448 children with 32 (7.1%) having a TC ≥ 5.3 mmol/L. The FH diagnosis was confirmed in three children (1:150 screened). Reverse cascade testing of other family members identified a further five individuals with FH; hence, eight new cases of FH were diagnosed from screening 448 children (1:56 screened). Ninety-six percent of parents would screen future children for FH. The approach was cost-effective, at $3979 per quality-adjusted life year gained. CONCLUSION: In Western Australia, universal screening of children aged 1-2 years for FH, undertaken at the time of an immunisation, was a feasible and effective approach to detect children, parents and other blood relatives with FH. The approach was acceptable to parents and is potentially a highly cost-effective detection strategy for families at risk of FH.


Assuntos
Hiperlipoproteinemia Tipo II , Austrália , Pré-Escolar , Testes Genéticos , Humanos , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/genética , Lactente , Programas de Rastreamento , Pais , Projetos Piloto
6.
Stem Cell Res ; 55: 102482, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34388489

RESUMO

Nemaline myopathy (NM) is a congenital myopathy typically characterized by skeletal muscle weakness and the presence of nemaline bodies in myofibres. Approximately 25% of NM cases are caused by variants in ACTA1. We generated two induced pluripotent stem cell lines from lymphoblastoid cells of a 10-year-old female with typical NM harbouring a dominant pathogenic variant in ACTA1 (c.541C>A). The isogenic lines displayed typical iPSC morphology, expressed pluripotency markers, and could differentiate into each of the three germ layers. Although the lines have partial or complete X chromosome duplication, they may still prove useful as models of human ACTA1 disease.


Assuntos
Células-Tronco Pluripotentes Induzidas , Miopatias da Nemalina , Actinas/genética , Criança , Feminino , Humanos , Músculo Esquelético , Mutação , Miopatias da Nemalina/genética
7.
BMC Cancer ; 21(1): 779, 2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34233636

RESUMO

BACKGROUND: There are no epidemiological studies describing rare cancers in Western Australia (WA). We aimed to fill this gap by estimating the incidence and five-year survival of rare, less common and common cancers in WA, based on definitions for rarity used by the Australian Institute of Health and Welfare and cancer groupings from the project on Surveillance of Rare Cancers in Europe (RARECARE). This research will enable policy- and decision-makers to better understand the size and nature of the public health problem presented by rare cancers in WA. It is anticipated that this study will inform improved health service design and delivery for all WA cancer patients, but particularly those with rare and less common cancers. METHODS: We estimated incidence and five-year survival rates of rare, less common and common cancers in WA using data sourced from the WA Cancer Registry for the 2013-2017 period. Cancers were defined as rare (< 6), less common (6-12), or common (> 12) based on their crude incidence rate per 100,000 people per year. RESULTS: Rare cancers make up 21.5% of all cancer diagnoses in WA, with a significantly poorer five-year survival of 58.2% (95% confidence interval (CI) 57.3-59.1%), compared to patients diagnosed with a common cancer, whose five-year survival was 87.8% (95% CI 87.3-88.3%). Survival for less common cancers was significantly poorer than both rare and common cancers, at 48.1% (95% CI 47.3-49.0%). Together, rare and less common cancers represent 48.4% of all cancer diagnoses in WA. CONCLUSIONS: While rare cancers are individually scarce, collectively over one in five cancer patients in WA are diagnosed with a rare cancer. These patients experience significantly worse prognoses compared to patients with common cancers.


Assuntos
Neoplasias/epidemiologia , Doenças Raras/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Neoplasias/mortalidade , Análise de Sobrevida , Austrália Ocidental , Adulto Jovem
8.
Stem Cell Res ; 53: 102273, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33740643

RESUMO

Nemaline myopathy (NM) is a congenital myopathy typically characterized by skeletal muscle weakness and the presence of abnormal thread- or rod-like structures (nemaline bodies) in myofibres. Pathogenic variants in the skeletal muscle alpha actin gene, ACTA1, cause approximately 25% of all NM cases. We generated two induced pluripotent stem cell lines from lymphoblastoid cells of a 4-month-old female with severe NM harbouring a dominant variant in ACTA1 (c.553C > A). The isogenic lines displayed characteristic iPSC morphology, expressed pluripotency markers, differentiated into cells of all three germ layers, and possessed normal karyotypes. These lines could be useful models of human ACTA1 disease.


Assuntos
Células-Tronco Pluripotentes Induzidas , Miopatias da Nemalina , Actinas/genética , Feminino , Humanos , Lactente , Músculo Esquelético , Mutação , Miopatias da Nemalina/genética
9.
Acta Neuropathol Commun ; 8(1): 142, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32819427

RESUMO

Ovine congenital progressive muscular dystrophy (OCPMD) was first described in Merino sheep flocks in Queensland and Western Australia in the 1960s and 1970s. The most prominent feature of the disease is a distinctive gait with stiffness of the hind limbs that can be seen as early as 3 weeks after birth. The disease is progressive. Histopathological examination had revealed dystrophic changes specifically in type I (slow) myofibres, while electron microscopy had demonstrated abundant nemaline bodies. Therefore, it was never certain whether the disease was a dystrophy or a congenital myopathy with dystrophic features. In this study, we performed whole genome sequencing of OCPMD sheep and identified a single base deletion at the splice donor site (+ 1) of intron 13 in the type I myofibre-specific TNNT1 gene (KT218690 c.614 + 1delG). All affected sheep were homozygous for this variant. Examination of TNNT1 splicing by RT-PCR showed intron retention and premature termination, which disrupts the highly conserved 14 amino acid C-terminus. The variant did not reduce TNNT1 protein levels or affect its localization but impaired its ability to modulate muscle contraction in response to Ca2+ levels. Identification of the causative variant in TNNT1 finally clarifies that the OCPMD sheep is in fact a large animal model of TNNT1 congenital myopathy. This model could now be used for testing molecular or gene therapies.


Assuntos
Miotonia Congênita/patologia , Miotonia Congênita/veterinária , Doenças dos Ovinos/genética , Doenças dos Ovinos/patologia , Troponina T/genética , Animais , Modelos Animais de Doenças , Músculo Esquelético/patologia , Ovinos
10.
Ann Clin Transl Neurol ; 7(3): 353-362, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32153140

RESUMO

OBJECTIVE: To develop, test, and iterate a comprehensive neuromuscular targeted gene panel in a national referral center. METHODS: We designed two iterations of a comprehensive targeted gene panel for neuromuscular disorders. Version 1 included 336 genes, which was increased to 464 genes in Version 2. Both panels used TargetSeqTM probe-based hybridization for target enrichment followed by Ion Torrent sequencing. Targeted high-coverage sequencing and analysis was performed on 2249 neurology patients from Australia and New Zealand (1054 Version 1, 1195 Version 2) from 2012 to 2015. No selection criteria were used other than referral from a suitable medical specialist (e.g., neurologist or clinical geneticist). Patients were classified into 15 clinical categories based on the clinical diagnosis from the referring clinician. RESULTS: Six hundred and sixty-five patients received a genetic diagnosis (30%). Diagnosed patients were significantly younger that undiagnosed patients (26.4 and 32.5 years, respectively; P = 4.6326E-9). The diagnostic success varied markedly between disease categories. Pathogenic variants in 10 genes explained 38% of the disease burden. Unexpected phenotypic expansions were discovered in multiple cases. Triage of unsolved cases for research exome testing led to the discovery of six new disease genes. INTERPRETATION: A comprehensive targeted diagnostic panel was an effective method for neuromuscular disease diagnosis within the context of an Australasian referral center. Use of smaller disease-specific panels would have precluded diagnosis in many patients and increased cost. Analysis through a centralized laboratory facilitated detection of recurrent, but under-recognized pathogenic variants.


Assuntos
Testes Genéticos/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Doenças Neuromusculares/diagnóstico , Doenças Neuromusculares/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Testes Genéticos/normas , Sequenciamento de Nucleotídeos em Larga Escala/normas , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Encaminhamento e Consulta , Adulto Jovem
11.
Acta Neuropathol Commun ; 8(1): 18, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-32066503

RESUMO

Nemaline myopathy (NM) caused by mutations in the gene encoding nebulin (NEB) accounts for at least 50% of all NM cases worldwide, representing a significant disease burden. Most NEB-NM patients have autosomal recessive disease due to a compound heterozygous genotype. Of the few murine models developed for NEB-NM, most are Neb knockout models rather than harbouring Neb mutations. Additionally, some models have a very severe phenotype that limits their application for evaluating disease progression and potential therapies. No existing murine models possess compound heterozygous Neb mutations that reflect the genotype and resulting phenotype present in most patients. We aimed to develop a murine model that more closely matched the underlying genetics of NEB-NM, which could assist elucidation of the pathogenetic mechanisms underlying the disease. Here, we have characterised a mouse strain with compound heterozygous Neb mutations; one missense (p.Tyr2303His), affecting a conserved actin-binding site and one nonsense mutation (p.Tyr935*), introducing a premature stop codon early in the protein. Our studies reveal that this compound heterozygous model, NebY2303H, Y935X, has striking skeletal muscle pathology including nemaline bodies. In vitro whole muscle and single myofibre physiology studies also demonstrate functional perturbations. However, no reduction in lifespan was noted. Therefore, NebY2303H,Y935X mice recapitulate human NEB-NM and are a much needed addition to the NEB-NM mouse model collection. The moderate phenotype also makes this an appropriate model for studying NEB-NM pathogenesis, and could potentially be suitable for testing therapeutic applications.


Assuntos
Códon sem Sentido , Proteínas Musculares/genética , Mutação de Sentido Incorreto , Miopatias da Nemalina/genética , Miopatias da Nemalina/patologia , Animais , Modelos Animais de Doenças , Feminino , Masculino , Camundongos Endogâmicos C57BL , Músculo Esquelético/ultraestrutura
12.
Hum Mol Genet ; 29(1): 20-30, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31511858

RESUMO

McArdle disease is a disorder of carbohydrate metabolism that causes painful skeletal muscle cramps and skeletal muscle damage leading to transient myoglobinuria and increased risk of kidney failure. McArdle disease is caused by recessive mutations in the muscle glycogen phosphorylase (PYGM) gene leading to absence of PYGM enzyme in skeletal muscle and preventing access to energy from muscle glycogen stores. There is currently no cure for McArdle disease. Using a preclinical animal model, we aimed to identify a clinically translatable and relevant therapy for McArdle disease. We evaluated the safety and efficacy of recombinant adeno-associated virus serotype 8 (rAAV8) to treat a murine model of McArdle disease via delivery of a functional copy of the disease-causing gene, Pygm. Intraperitoneal injection of rAAV8-Pygm at post-natal day 1-3 resulted in Pygm expression at 8 weeks of age, accompanied by improved skeletal muscle architecture, reduced accumulation of glycogen and restoration of voluntary running wheel activity to wild-type levels. We did not observe any adverse reaction to the treatment at 8 weeks post-injection. Thus, we have investigated a highly promising gene therapy for McArdle disease with a clear path to the ovine large animal model endemic to Western Australia and subsequently to patients.


Assuntos
Glicogênio Fosforilase Muscular/metabolismo , Doença de Depósito de Glicogênio Tipo V/metabolismo , Glicogênio/metabolismo , Músculo Esquelético/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Glicogênio Fosforilase Muscular/genética , Doença de Depósito de Glicogênio Tipo V/genética , Inflamação/genética , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL
13.
NPJ Regen Med ; 4: 5, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30854227

RESUMO

Clinical variation in patient responses to myocardial infarction (MI) has been difficult to model in laboratory animals. To assess the genetic basis of variation in outcomes after heart attack, we characterized responses to acute MI in the Collaborative Cross (CC), a multi-parental panel of genetically diverse mouse strains. Striking differences in post-MI functional, morphological, and myocardial scar features were detected across 32 CC founder and recombinant inbred strains. Transcriptomic analyses revealed a plausible link between increased intrinsic cardiac oxidative phosphorylation levels and MI-induced heart failure. The emergence of significant quantitative trait loci for several post-MI traits indicates that utilizing CC strains is a valid approach for gene network discovery in cardiovascular disease, enabling more accurate clinical risk assessment and prediction.

14.
Front Public Health ; 7: 42, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30899755

RESUMO

Advances in precision medicine have presented challenges to traditional public health decision-making paradigms. Historical methods of allocating healthcare funds based on safety, efficacy, and efficiency, are challenged in a healthcare delivery model that focuses on individualized variations in pathology that form the core of precision medicine. Public health policy and decision-making must adapt to this new frontier of healthcare delivery to ensure that the broad public health goals of reducing healthcare disparities and improving the health of populations are achieved, through effective and equitable allocation of healthcare funds. This paper discusses contemporary applications of precision medicine, and the potential impacts of these on public health policy and decision-making, with particular focus on patients living with rare diseases and rare cancers. The authors then reconcile these, presenting precision public health as the bridge between these seemingly competing fields.

15.
Front Public Health ; 7: 40, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30915323

RESUMO

The expanding use of genomic technologies encompasses all phases of life, from the embryo to the elderly, and even the posthumous phase. In this paper, we present the spectrum of genomic healthcare applications, and describe their scope and challenges at different stages of the life cycle. The integration of genomic technology into healthcare presents unique ethical issues that challenge traditional aspects of healthcare delivery. These challenges include the different definitions of utility as applied to genomic information; the particular characteristics of genetic data that influence how it might be protected, used and shared; and the difficulties applying existing models of informed consent, and how new consent models might be needed.

16.
Front Public Health ; 7: 41, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30915324

RESUMO

This paper examines key considerations for the successful integration of genomic technologies into healthcare systems. All healthcare systems strive to introduce new technologies that are effective and affordable, but genomics offers particular challenges, given the rapid evolution of the technology. In this context we frame internationally relevant discussion points relating to effective and sustainable implementation of genomic testing within the strategic priority areas of the recently endorsed Australian National Health Genomics Policy Framework. The priority areas are services, data, workforce, finances, and person-centred care. In addition, we outline recommendations from a government perspective through the lens of the Australian health system, and argue that resources should be allocated not to just genomic testing alone, but across the five strategic priority areas for full effectiveness.

17.
Front Physiol ; 9: 1756, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30564146

RESUMO

Myopathies are notably associated with mutations in genes encoding proteins known to be essential for the force production of skeletal muscle fibers, such as skeletal alpha-actin. The exact molecular mechanisms by which these specific defects induce myopathic phenotypes remain unclear. Hence, in the present study, to better understand actin dysfunction, we conducted a molecular dynamic simulation together with ex vivo experiments of the specific muscle disease-causing actin mutation, D286G located in the actin-actin interface. Our computational study showed that D286G impairs the flexural rigidity of actin filaments. However, upon activation, D286G did not have any direct consequences on actin filament extension. Hence, D286G may alter the structure of actin filaments but, when expressed together with normal actin molecules, it may only have minor effects on the ex vivo mechanics of actin filaments upon skeletal muscle fiber contraction.

18.
Front Public Health ; 6: 247, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30234091

RESUMO

Public health genomics has evolved to responsibly integrate advancements in genomics into the fields of personalized medicine and public health. Appropriate, effective and sustainable integration of genomics into healthcare requires an organized approach. This paper outlines the history that led to the emergence of public health genomics as a distinguishable field. In addition, a range of activities are described that illustrate how genomics can be incorporated into public health practice. Finally, it presents the evolution of public health genomics into the new era of "precision public health."

19.
Sci Rep ; 8(1): 11490, 2018 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-30065346

RESUMO

L-tyrosine supplementation may provide benefit to nemaline myopathy (NM) patients, however previous studies are inconclusive, with no elevation of L-tyrosine levels in blood or tissue reported. We evaluated the ability of L-tyrosine treatments to improve skeletal muscle function in all three published animal models of NM caused by dominant skeletal muscle α-actin (ACTA1) mutations. Highest safe L-tyrosine concentrations were determined for dosing water and feed of wildtype zebrafish and mice respectively. NM TgACTA1D286G-eGFP zebrafish treated with 10 µM L-tyrosine from 24 hours to 6 days post fertilization displayed no improvement in swimming distance. NM TgACTA1D286G mice consuming 2% L-tyrosine supplemented feed from preconception had significant elevations in free L-tyrosine levels in sera (57%) and quadriceps muscle (45%) when examined at 6-7 weeks old. However indicators of skeletal muscle integrity (voluntary exercise, bodyweight, rotarod performance) were not improved. Additionally no benefit on the mechanical properties, energy metabolism, or atrophy of skeletal muscles of 6-7 month old TgACTA1D286G and KIActa1H40Y mice eventuated from consuming a 2% L-tyrosine supplemented diet for 4 weeks. Therefore this study yields important information on aspects of the clinical utility of L-tyrosine for ACTA1 NM.


Assuntos
Actinas/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Miopatias da Nemalina/tratamento farmacológico , Miopatias da Nemalina/metabolismo , Tirosina/administração & dosagem , Peixe-Zebra/metabolismo , Animais , Suplementos Nutricionais , Modelos Animais de Doenças , Metabolismo Energético/efeitos dos fármacos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mutação/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA