152 research outputs found

    Bi-allelic mutations in MYL1 cause a severe congenital myopathy.

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    OBJECTIVE: Congenital myopathies are typically characterised by early onset hypotonia, weakness and hallmark features on biopsy. Despite the rapid pace of gene discovery, approximately 50% of patients with a congenital myopathy remain without a genetic diagnosis following screening of known disease genes. METHODS: We performed exome sequencing on two consanguineous probands diagnosed with a congenital myopathy and muscle biopsy showing selective atrophy/hypotrophy or absence of type II myofibres. RESULTS: We identified variants in the gene (MYL1) encoding the skeletal muscle fast-twitch specific myosin essential light chain in both probands. A homozygous essential splice acceptor variant (c.479-2A>G, predicted to result in skipping of exon 5 was identified in Proband 1, and a homozygous missense substitution (c.488T>G, p.(Met163Arg)) was identified in Proband 2. Protein modeling of the p.(Met163Arg) substitution predicted it might impede intermolecular interactions that facilitate binding to the IQ domain of myosin heavy chain, thus likely impacting on the structure and functioning of the myosin motor. MYL1 was markedly reduced in skeletal muscle from both probands, suggesting that the missense substitution likely results in an unstable protein. Knock down of myl1 in zebrafish resulted in abnormal morphology, disrupted muscle structure and impaired touch-evoked escape responses, thus confirming that skeletal muscle fast-twitch specific myosin essential light chain is critical for myofibre development and function. INTERPRETATION: Our data implicate MYL1 as a crucial protein for adequate skeletal muscle function and that MYL1 deficiency is associated with a severe congenital myopathy

    Fibroblast growth factor 19 expression correlates with tumor progression and poorer prognosis of hepatocellular carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Although fibroblast growth factor 19 (FGF19) can promote liver carcinogenesis in mice, its involvement in human hepatocellular carcinoma (HCC) has not been well investigated. FGF19, a member of the FGF family, has unique specificity for its receptor FGFR4. This study aimed to clarify the involvement of FGF19 in the development of HCC.</p> <p>Methods</p> <p>We investigated human FGF19 and FGFR4 expression in 40 hepatocellular carcinoma specimens using quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) analysis and immunohistochemistry. Moreover, we examined the expression and the distribution of FGF19 and FGFR4 in 5 hepatocellular carcinoma cell lines (HepG2, HuH7, HLE, HLF, and JHH7) using RT-PCR and immunohistochemistry. To test the role of the FGF19/FGFR4 system in tumor progression, we used recombinant FGF19 protein and small interfering RNA (siRNA) of <it>FGF19 </it>and <it>FGFR4 </it>to regulate their concentrations.</p> <p>Results</p> <p>We found that FGF19 was significantly overexpressed in HCCs as compared with corresponding noncancerous liver tissue (<it>P </it>< 0.05). Univariate and multivariate analyses revealed that the tumor <it>FGF19 </it>mRNA expression was an independent prognostic factor for overall and disease-free survival. Moreover, we found that the FGF19 recombinant protein could increase the proliferation (<it>P </it>< 0.01, <it>n </it>= 12) and invasion (<it>P </it>< 0.01, <it>n </it>= 6) capabilities of human hepatocellular carcinoma cell lines and inhibited their apoptosis (<it>P </it>< 0.01, <it>n </it>= 12). Inversely, decreasing <it>FGF19 </it>and <it>FGFR4 </it>expression by siRNA significantly inhibited proliferation and increased apoptosis in JHH7 cells (<it>P </it>< 0.01, <it>n </it>= 12). The postoperative serum FGF19 levels in HCC patients was significantly lower than the preoperative levels (<it>P </it>< 0.01, <it>n </it>= 29).</p> <p>Conclusions</p> <p>FGF19 is critically involved in the development of HCCs. Targeting FGF19 inhibition is an attractive potential therapeutic strategy for HCC.</p

    Association study in the 5q31-32 linkage region for schizophrenia using pooled DNA genotyping

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    <p>Abstract</p> <p>Background</p> <p>Several linkage studies suggest that chromosome 5q31-32 might contain risk loci for schizophrenia (SZ). We wanted to identify susceptibility genes for schizophrenia within this region.</p> <p>Methods</p> <p>We saturated the interval between markers D5S666 and D5S436 with 90 polymorphic microsatellite markers and genotyped two sets of DNA pools consisting of 300 SZ patients of Bulgarian origin and their 600 parents. Positive associations were followed-up with SNP genotyping.</p> <p>Results</p> <p>Nominally significant evidence for association (p < 0.05) was found for seven markers (D5S0023i, IL9, RH60252, 5Q3133_33, D5S2017, D5S1481, D5S0711i) which were then individually genotyped in the trios. The predicted associations were confirmed for two of the markers: D5S2017, localised in the <it>SPRY4-FGF1 </it>locus (p = 0.004) and IL9, localized within the IL9 gene (p = 0.014). Fine mapping was performed using single nucleotide polymorphisms (SNPs) around D5S2017 and IL9. In each region four SNPs were chosen and individually genotyped in our full sample of 615 SZ trios. Two SNPs showed significant evidence for association: rs7715300 (p = 0.001) and rs6897690 (p = 0.032). Rs7715300 is localised between the <it>TGFBI </it>and <it>SMAD5 </it>genes and rs6897690 is within the <it>SPRY4 </it>gene.</p> <p>Conclusion</p> <p>Our screening of 5q31-32 implicates three potential candidate genes for SZ: <it>SMAD5</it>, <it>TGFBI </it>and <it>SPRY4</it>.</p

    Heterozygous frameshift variants in HNRNPA2B1 cause early-onset oculopharyngeal muscular dystrophy

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    Missense variants in RNA-binding proteins (RBPs) underlie a spectrum of disease phenotypes, including amyotrophic lateral sclerosis, frontotemporal dementia, and inclusion body myopathy. Here, we present ten independent families with a severe, progressive muscular dystrophy, reminiscent of oculopharyngeal muscular dystrophy (OPMD) but of much earlier onset, caused by heterozygous frameshift variants in the RBP hnRNPA2/B1. All disease-causing frameshift mutations abolish the native stop codon and extend the reading frame, creating novel transcripts that escape nonsense-mediated decay and are translated to produce hnRNPA2/B1 protein with the same neomorphic C-terminal sequence. In contrast to previously reported disease-causing missense variants in HNRNPA2B1, these frameshift variants do not increase the propensity of hnRNPA2 protein to fibrillize. Rather, the frameshift variants have reduced affinity for the nuclear import receptor karyopherin β2, resulting in cytoplasmic accumulation of hnRNPA2 protein in cells and in animal models that recapitulate the human pathology. Thus, we expand the phenotypes associated with HNRNPA2B1 to include an early-onset form of OPMD caused by frameshift variants that alter its nucleocytoplasmic transport dynamics

    Exome reanalysis and proteomic profiling identified TRIP4 as a novel cause of cerebellar hypoplasia and spinal muscular atrophy (PCH1)

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    TRIP4 is one of the subunits of the transcriptional coregulator ASC-1, a ribonucleoprotein complex that participates in transcriptional coactivation and RNA processing events. Recessive variants in the TRIP4 gene have been associated with spinal muscular atrophy with bone fractures as well as a severe form of congenital muscular dystrophy. Here we present the diagnostic journey of a patient with cerebellar hypoplasia and spinal muscular atrophy (PCH1) and congenital bone fractures. Initial exome sequencing analysis revealed no candidate variants. Reanalysis of the exome data by inclusion in the Solve-RD project resulted in the identification of a homozygous stop-gain variant in the TRIP4 gene, previously reported as disease-causing. This highlights the importance of analysis reiteration and improved and updated bioinformatic pipelines. Proteomic profile of the patient’s fibroblasts showed altered RNA-processing and impaired exosome activity supporting the pathogenicity of the detected variant. In addition, we identified a novel genetic form of PCH1, further strengthening the link of this characteristic phenotype with altered RNA metabolism

    Glucose management for exercise using continuous glucose monitoring: should sex and prandial state be additional considerations? Reply to Yardley JE and Sigal RJ [letter]

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    Oral diseases are a significant global health problem across all countries and populations. With about 3.5 billion cases (2017), more people are affected than by any other disease group. The main oral diseases comprise tooth decay of permanent and deciduous teeth, severe periodontal disease, and oral and lip cancer. With a largely unchanged high global prevalence, but significantly growing population sizes, the pressure on health systems is increasing, particularly in low- and middle-income countries.Nonetheless, in many countries oral health has insufficient priority as a key health topic, including the global health policy discourse of German and international stakeholders. One of the fundamental challenges is ensuring universal and equitable access to basic oral healthcare services for all and without financial hardship (Universal Health Coverage).This paper provides an introductory overview of the global trends for the main oral diseases, which are generally characterized by stark inequalities. Opportunities for improving the situation through population-wide risk reduction and preventive approaches, access to oral healthcare, and policy options are highlighted. In addition, a range of relevant global (oral) health topics with potential for tangible change are discussed. Lastly, the reform areas of the Lancet Series on Oral Health from 2019 are presented and recommendations for the German and international global health policy discourse are provided
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