Publications by authors named "Hannah-Ruth Engelbrecht"

Article Synopsis
  • The Illumina MethylationEPIC BeadChip microarray platform has two versions (v1.0 and v2.0), which show high correlation overall but varying results at the probe level for tools assessing DNA methylation effects.
  • Research using blood samples from different adult age groups found that samples clustered more by the EPIC version used than by other characteristics, indicating significant differences in data outputs between the two versions.
  • The study emphasizes the need to consider which EPIC version is used when analyzing data for meta-analyses and longitudinal studies, as these differences can impact findings in epigenome-wide association studies (EWAS).
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Sex differences in aging manifest in disparities in disease prevalence, physical health, and lifespan, where women tend to have greater longevity relative to men. However, in the Mediterranean Blue Zones of Sardinia (Italy) and Ikaria (Greece) are regions of centenarian abundance, male-female centenarian ratios are approximately one, diverging from the typical trend and making these useful regions in which to study sex differences of the oldest old. Additionally, these regions can be investigated as examples of healthy aging relative to other populations.

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Smoking-associated DNA methylation (DNAm) signatures are reproducible among studies of mostly European descent, with mixed evidence if smoking accelerates epigenetic aging and its relationship to longevity. We evaluated smoking-associated DNAm signatures in the Costa Rican Study on Longevity and Healthy Aging (CRELES), including participants from the high longevity region of Nicoya. We measured genome-wide DNAm in leukocytes, tested Epigenetic Age Acceleration (EAA) from five clocks and estimates of telomere length (DNAmTL), and examined effect modification by the high longevity region.

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Background: Bipolar disorder (BD) has considerable heritability, with genome-wide association studies indicating that multiple common genetic variants contribute to risk. Less work has been undertaken to assess the contribution of rare variation in the development of this complex disorder, particularly in isolated populations. Using whole-exome sequencing (WES), the aim of this study was to identify rare, potentially damaging variants contributing to risk for BD in the Afrikaner population.

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Article Synopsis
  • Scientists studied the brain's outer layer, called the cerebral cortex, to learn how genes can affect its structure.
  • They looked at brain scans from over 51,000 people and found 199 important genetic markers that relate to how the cortex is shaped.
  • The study showed that these genetic markers are linked to different brain functions and conditions like thinking skills, sleep problems, and ADHD.
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