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Collagen alpha-1(VI) chain precursor


Epigenome-wide exploratory study of monozygotic twins suggests differentially methylated regions to associate with hand grip strength.

Hand grip strength is a measure of muscular strength and is used to study age-related loss of physical capacity. In order to explore the biological mechanisms that influence hand grip strength variation, an epigenome-wide association study (EWAS) of hand grip strength in 672 middle-aged and elderly monozygotic twins (age 55-90 years) was performed, using both individual and twin pair level analyses, the latter controlling the influence of genetic variation. Moreover, as measurements of hand grip strength performed over 8 years were available in the elderly twins (age 73-90 at intake), a longitudinal EWAS was conducted for this subsample. No genome-wide significant CpG sites or pathways were found, however two of the suggestive top CpG sites were mapped to the COL6A1 and CACNA1B genes, known to be related to muscular dysfunction. By investigating genomic regions using the comb-p algorithm, several differentially methylated regions in regulatory domains were identified as significantly associated to hand grip strength, and pathway analyses of these regions revealed significant pathways related to the immune system, autoimmune disorders, including diabetes type 1 and viral myocarditis, as well as negative regulation of cell differentiation. The genes contributing to the immunological pathways were HLA-B, HLA-C, HLA-DMA, HLA-DPB1, MYH10, ERAP1 and IRF8, while the genes implicated in the negative regulation of cell differentiation were IRF8, CEBPD, ID2 and BRCA1. In conclusion, this exploratory study suggests hand grip strength to associate with differentially methylated regions enriched in immunological and cell differentiation pathways, and hence merits further investigations.

MeSH Terms

  • Aged
  • Aging
  • Cell Differentiation
  • CpG Islands
  • Cross-Sectional Studies
  • DNA Methylation
  • Denmark
  • Epigenesis, Genetic
  • Epigenome
  • Female
  • Genome-Wide Association Study
  • Hand Strength
  • Humans
  • Immunity
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Twins, Monozygotic


  • Comb-p
  • Epigenome-wide association study
  • Hand grip strength
  • Longitudinal data
  • Pathway analyses
  • Twin data

Genome-wide DNA methylation profiles reveal novel candidate genes associated with meat quality at different age stages in hens.

Poultry meat quality is associated with breed, age, tissue and other factors. Many previous studies have focused on distinct breeds; however, little is known regarding the epigenetic regulatory mechanisms in different age stages, such as DNA methylation. Here, we compared the global DNA methylation profiles between juvenile (20 weeks old) and later laying-period (55 weeks old) hens and identified candidate genes related to the development and meat quality of breast muscle using whole-genome bisulfite sequencing. The results showed that the later laying-period hens, which had a higher intramuscular fat (IMF) deposition capacity and water holding capacity (WHC) and less tenderness, exhibited higher global DNA methylation levels than the juvenile hens. A total of 2,714 differentially methylated regions were identified in the present study, which corresponded to 378 differentially methylated genes, mainly affecting muscle development, lipid metabolism, and the ageing process. Hypermethylation of the promoters of the genes ABCA1, COL6A1 and GSTT1L and the resulting transcriptional down-regulation in the later laying-period hens may be the reason for the significant difference in the meat quality between the juvenile and later laying-period hens. These findings contribute to a better understanding of epigenetic regulation in the skeletal muscle development and meat quality of chicken.

MeSH Terms

  • Aging
  • Animals
  • Chickens
  • DNA Methylation
  • Epigenesis, Genetic
  • Food Quality
  • Lipid Metabolism
  • Meat
  • Muscle, Skeletal
  • Whole Genome Sequencing

Bethlem myopathy: long-term follow-up identifies COL6 mutations predicting severe clinical evolution.

Mutations in one of the 3 genes encoding collagen VI (COLVI) are responsible for a group of heterogeneous phenotypes of which Bethlem myopathy (BM) represents the milder end of the spectrum. Genotype-phenotype correlations and long-term follow-up description in BM remain scarce. We retrospectively evaluated the long-term clinical evolution, and genotype-phenotype correlations in 35 genetically identified BM patients (23 index cases). Nineteen patients showed a typical clinical picture with contractures, proximal weakness and slow disease progression while 11 presented a more severe evolution. Five patients showed an atypical presentation, namely a limb girdle muscle weakness in 2 and a congenital myopathy pattern with either no contractures, or only limited to ankles, in 3 of them. Pathogenic COL6A1-3 mutations were mostly missense or in frame exon-skipping resulting in substitutions or deletions. Twenty one different mutations were identified including 12 novel ones. The mode of inheritance was, autosomal dominant in 83% of the index patients (including 17% (N=4) with a de novo mutation), recessive in 13%, and undetermined in one patient. Skipping of exon 14 of COL6A1 was found in 35% of index cases and was mostly associated with a severe clinical evolution. Missense mutations were detected in 39% of index cases and associated with milder forms of the disease. Long-term follow-up identified important phenotypic variability in this cohort of 35 BM patients. However, worsening of the functional disability appeared typically after the age of 40 in 47% of our patients, and was frequently associated with COL6A1 exon 14 skipping.

MeSH Terms

  • Adolescent
  • Adult
  • Age of Onset
  • Aging
  • Biopsy
  • Child
  • Child, Preschool
  • Cohort Studies
  • Collagen Type VI
  • Contracture
  • Disease Progression
  • Exons
  • Female
  • Follow-Up Studies
  • Genotype
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Muscle Weakness
  • Muscular Dystrophies
  • Mutation
  • Mutation, Missense
  • Neurologic Examination
  • Phenotype
  • Retrospective Studies
  • Tomography, X-Ray Computed
  • Young Adult