Comprehensive analysis of epigenetic clocks reveals associations between disproportionate biological ageing and hippocampal volume

The concept of age acceleration, the difference between biological age and chronological age, is of growing interest, particularly with respect to age-related disorders, such as Alzheimer’s Disease (AD). Whilst studies have reported associations with AD risk and related phenotypes, there remains a lack of consensus on these associations. Here we aimed to comprehensively investigate the relationship between five recognised measures of age acceleration, based on DNA methylation patterns (DNAm age), and cross-sectional and longitudinal cognition and AD-related neuroimaging phenotypes (volumetric MRI and Amyloid-β PET) in the Australian Imaging, Biomarkers and Lifestyle (AIBL) and the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Significant associations were observed between age acceleration using the Hannum epigenetic clock and cross-sectional hippocampal volume in AIBL and replicated in ADNI. In AIBL, several other findings were observed cross-sectionally, including a significant association between hippocampal volume and the Hannum and Phenoage epigenetic clocks. Further, significant associations were also observed between hippocampal volume and the Zhang and Phenoage epigenetic clocks within Amyloid-β positive individuals. However, these were not validated within the ADNI cohort. No associations between age acceleration and other Alzheimer’s disease-related phenotypes, including measures of cognition or brain Amyloid-β burden, were observed, and there was no association with longitudinal change in any phenotype. This study presents a link between age acceleration, as determined using DNA methylation, and hippocampal volume that was statistically significant across two highly characterised cohorts. The results presented in this study contribute to a growing literature that supports the role of epigenetic modifications in ageing and AD-related phenotypes

Uncovering the heterogeneity and temporal complexity of neurodegenerative diseases with Subtype and Stage Inference

The heterogeneity of neurodegenerative diseases is a key confound to disease understanding and treatment development, as study cohorts typically include multiple phenotypes on distinct disease trajectories. Here we introduce a machine-learning technique\u2014Subtype and Stage Inference (SuStaIn)\u2014able to uncover data-driven disease phenotypes with distinct temporal progression patterns, from widely available cross-sectional patient studies. Results from imaging studies in two neurodegenerative diseases reveal subgroups and their distinct trajectories of regional neurodegeneration. In genetic frontotemporal dementia, SuStaIn identifies genotypes from imaging alone, validating its ability to identify subtypes; further the technique reveals within-genotype heterogeneity. In Alzheimer\u2019s disease, SuStaIn uncovers three subtypes, uniquely characterising their temporal complexity. SuStaIn provides fine-grained patient stratification, which substantially enhances the ability to predict conversion between diagnostic categories over standard models that ignore subtype (p = 7.18 7 10 124 ) or temporal stage (p = 3.96 7 10 125 ). SuStaIn offers new promise for enabling disease subtype discovery and precision medicine

Does presence of a VACTERL anomaly predict an associated gynecologic anomaly in females with anorectal malformations?: A Pediatric Colorectal and Pelvic Learning Consortium Study.

BACKGROUND: VACTERL association is defined by the presence of 3 or more anomalies in any of the following systems: vertebral, anorectal, cardiac, trachea-esophageal, renal, or limb. This study hypothesized that the presence of VACTERL association would correlate with an increased risk of gynecologic anomalies in patients with anorectal malformation (ARM). METHODS: This study is a cross-sectional, retrospective analysis from the prospectively collected, multicenter registry of the Pediatric Colorectal and Pelvic Learning Consortium (PCPLC). The 834 female patients with ARM who were enrolled in the registry by January 1, 2020 were included in this study. The relationship of VACTERL association with presence of a gynecologic anomaly was evaluated with Fisher's exact test. The relationship of each VACTERL system with presence of a gynecologic anomaly was assessed in patients with cloaca, rectovestibular fistulas and rectoperineal fistulas. P-values reported were based on a 2-sided alternative and considered significant when less than 0.05. RESULTS: 834 patients with ARM underwent VACTERL screening and gynecologic evaluation with the three most common subtypes being cloaca (n = 215, 25.8%), rectovestibular fistula (n = 191, 22.9%) and rectoperineal fistula (n = 194, 23.3%). A total of 223 (26.7%) patients with ARM had gynecologic anomalies. VACTERL association was seen in 380 (45.6%) of patients with ARM. Gynecologic anomalies were present in 149 (39.1%) vs. 74 (16.3%) of subjects with vs. without VACTERL association (p < 0.001). VACTERL association did not significantly increase the risk of gynecologic anomaly in patients with cloaca and VACTERL (n = 88, 61.5%) vs. cloaca without VACTERL (n = 39, 54.2% p = 0.308). VACTERL association increased the risk of gynecologic anomalies in patients with rectoperineal fistulas (n = 7, 14.9% vs n = 9, 6.1% p = 0.014) and rectovestibular fistulas (n = 19, 31.1% vs. n = 13, 10.0% p<0.001). In patients with ARM who had a VACTERL association, when one of the associated anomalies was renal, there was an even higher risk of having an associated gynecologic anomaly (n = 138, 44.2% vs. n = 85, 16.3% p<0.001). CONCLUSIONS: VACTERL association in patients with rectoperineal and rectovestibular fistulas correlates with an increased risk of gynecologic anomalies. The presence of VACTERL associated findings, especially renal, should prompt a thorough evaluation of the gynecologic system. LEVEL OF EVIDENCE: III. Retrospective comparative study