Autism spectrum disorders (ASDs) constitute a set of heterogeneous neurodevelopmental conditions, characterized by a wide genetic variability that has led to hypothesize a polygenic origin. The metabolic profiles of patients with ASD suggest a possible implication of mitochondrial pathways. Although different physiological and biochemical studies reported deficits in mitochondrial oxidative phosphorylation in subjects with ASD, the role of mitochondrial DNA variations has remained relatively unexplored. In this review, we report and discuss very recent evidence to demonstrate the key role of mitochondrial disorders in the development of ASD.

In the last decade, extensive efforts have been made to identify biomarkers of biological age. DNA methylation levels of ELOVL fatty acid elongase 2 (ELOVL2) and the signal joint T-cell receptor rearrangement excision circles (sjTRECs) represent the most promising candidates. Although these two non-redundant biomarkers echo important biological aspects of the ageing process in humans, a well-validated molecular clock exploiting these powerful candidates has not yet been formulated. The present study aimed to develop a more accurate molecular clock in a sample of 194 Italian individuals by re-analyzing the previously obtained EVOLV2 methylation data together with the amount of sjTRECs in the same blood samples. The proposed model showed a high prediction accuracy both in younger individuals with an error of about 2.5 years and in older subjects where a relatively low error was observed if compared with those reported in previously published studies. In conclusion, an easy, cost-effective and reliable model to measure the individual rate and the quality of aging in human population has been proposed. Further studies are required to validate the model and to extend its use in an applicative context.

Hyperekplexia also known as Startle disease is a rare neuromotor hereditary disorder characterized by exaggerated startle responses to unexpected auditory, tactile, and visual stimuli and generalized muscle stiffness, which both gradually subside during the first months of life. Although the diagnosis of Hyperekplexia is based on clinical findings, pathogenic variants in five genes have been reported to cause Hyperekplexia, of which GLRA1 accounts for about 80% of cases. Dominant and recessive mutations have been identified in GLRA1 gene as pathogenic variants in many individuals with the familial form of Hyperekplexia and occasionally in simplex cases. In the present study, we describe clinical and genetic features of two Italian siblings, one with the major and one with the minor form of the disease. DNA samples from the probands and their parents were performed by NGS approach and validated by Sanger sequencing. The analysis of the GLRA1 gene revealed, in both probands, compound heterozygous mutations: c.895C > T or p.R299X inherited from the mother and c.587C > A or p.D98E inherited from the father. Until now, these two identified mutations in GLRA1 have not been reported before as compound mutations. What clearly emerges within our study is the clinical heterogeneity in the same family. In fact, even though in the same pedigree, the affected mother showed only mild startle responses to unexpected noise stimuli, which might be explained by variable expressivity, while the father, showed no clear signs of symptomatology, which might be explained by non-penetrance. Finally, the two brothers have different form of the disease, even if the compound heterozygous mutations in GLRA1 are the same, showing that the same mutation in GLRA1 could have different phenotypic expressions and suggesting an underling mechanism of variable expressivity.

Nowadays, scientists are making efforts to elucidate the mechanisms involved in the phenotypic changes underlying the aging process in order to develop favorable therapeutical interventions. Epigenetic modifications, in particular DNA methylation, play a crucial role in the aging process, and this parameter has been used to set epigenetic clocks, algorithms that predict an individual’s biological age based on a defined set of CpGs. In this review, we focus on the most recent literature to discuss the use of epigenetic clocks in the context of cognitive decline and dysregulation of Alzheimer’s disease (AD)-related gene expression. We have summarized all published scientific papers in which epigenetic clocks have been applied to measure age acceleration in blood and brain specimens from patients affected with AD. Progressive age acceleration, consistent with a specific DNA methylation signature, was observed in patients affected by AD, and it was correlated with the onset of complex diseases, mitochondrial alterations, dementia and cognitive decline, even in the early stages of these conditions. The use of epigenetic clocks might be a valuable biomarker to enable an earlier identification of ideal measures to reverse modifications caused by aging and to mitigate multiple aspects of disease/aging mechanisms.

Cardiovascular diseases (CVDs) remain a leading cause of death worldwide. Mitochondria, essential organelles within cells, play a crucial role in maintaining cardiovascular health by producing energy through ATP synthesis. The heart’s high energy demand makes it particularly sensitive to mitochondrial function. In CVDs, mitochondrial adaptability is compromised, resulting in dysfunction characterized by impaired respiratory chain activity, decreased ATP production, oxidative stress, and structural damage. This review consolidates current research on mitochondrial roles in CVD development, focusing on mitochondrial respiration, ATP synthesis, and the processes involved in maintaining mitochondrial quality, such as mitophagy. It discusses the challenges in developing therapies aimed at restoring mitochondrial function, including drug delivery issues and targeting specificity. The assessment includes analysis of mitochondrial anomalies associated with cardiac disease progression and potential therapeutic strategies. Mitochondrial dysfunction contributes to the progression of various CVDs by reducing energy output and increasing oxidative stress, leading to cardiomyocyte injury and death. Damaged mitochondria produce excessive reactive oxygen species (ROS), exacerbating cellular damage. Repairing mitochondrial components, especially the respiratory chain and ATP synthesis pathways, has shown potential in mitigating cellular injury and improving cardiac function. Restoring mitochondrial function is vital for preventing and treating CVDs. Targeted therapies that repair mitochondrial respiratory activity and enhance ATP production may reduce cellular damage, promote cardiomyocyte survival, and improve clinical outcomes. Understanding mitochondrial dynamics offers promising avenues for innovative interventions in cardiovascular health management.