The secondary sex ratio (SSR), indicating the ratio of male to female live births, has garnered considerable attention within the realms of reproductive biology and public health. Numerous factors have been posited as potential trendsetters of the SSR. Given the extensive research on the impact of daily behaviors and habits on individuals’ reproductive health, there is a plausible suggestion that lifestyle choices may also influence the SSR. By synthesizing the existing literature on the current research field, this comprehensive review indicates that an elevated SSR has been associated with an increased intake of fatty acids and monosaccharides, proper nutrition, higher educational levels, financial prosperity, and favorable housing conditions. On the other hand, a decreased SSR may be linked to undernutrition, socioeconomic disparities, and psychological distress, aligning with the Trivers–Willard hypothesis. Occupational factors, smoking habits, and cultural beliefs could also contribute to trends in the SSR. Our review underscores the significance of considering the aforementioned factors in studies examining the SSR and emphasizes the necessity for further research to unravel the mechanisms underpinning these connections. A more profound comprehension of SSR alterations due to lifestyle holds the potential to adequately develop public health interventions and healthcare strategies to enhance reproductive health and overall well-being.

The secondary sex ratio (SSR), defined as the ratio of male to female births in a population, has long been a subject of scientific inquiry due to its potential as a health indicator. The interplay between catastrophic events and the delicate balance of male and female births presents a nuanced and compelling study area. Natural disasters, such as earthquakes, hurricanes, floods, and volcanic eruptions, have been known to disrupt ecosystems and human populations, leading to both short-term and long-term consequences. Studies have suggested a potential influence of these disasters on the SSR, with varying degrees of impact observed across different regions and disaster types. Similarly, nuclear accidents, such as the infamous Chernobyl disaster, have sparked interest in their potential effects on human health and development. The release of radioactive materials into the environment can have far-reaching consequences, including impacts on reproductive outcomes. Through a rigorous examination of the existing literature, the present review aims to synthesize current knowledge on the impacts of natural disasters and nuclear accidents on the SSR and unravel the mechanisms that explain SSR fluctuations. By shedding light on the diverse influences shaping the SSR, this narrative review contributes to a deeper appreciation of the intricate interplay between environmental, biological, and societal factors that determines the SSR, calling for targeted strategies to mitigate potential adverse effects on sex ratios in the aftermath of such events.

Neurocutaneous syndromes represent a clinically and genetically heterogeneous group of disorders, with tuberous sclerosis complex (TSC), von Hippel–Lindau syndrome (VHL), and ataxia–telangiectasia (A-T) exemplifying some of the most complex entities within this category. These syndromes have traditionally been considered monogenic disorders, caused by germline mutations in tumor suppressor or regulatory genes. However, they exhibit a striking degree of phenotypic variability and divergent clinical trajectories that cannot be fully explained by their underlying genetic alterations alone. Increasingly, epigenetic regulatory mechanisms, such as DNA methylation, histone modifications, chromatin remodeling, and non-coding RNA (ncRNA) activity, are recognized as key modulators of gene expression, cellular differentiation, and tissue-specific function. Disruption of these mechanisms has been implicated in disease pathogenesis, tumorigenesis, and neurodegeneration associated with TSC, VHL, and A-T. Aberrant epigenetic profiles may underlie the observed variability in clinical outcomes, even among individuals with identical mutations. This review consolidates current evidence on the epigenetic landscape of these syndromes, elucidating how these modifications may influence disease behavior and contribute to incomplete genotype–phenotype correlations. By integrating epigenetic insights with known molecular pathways, a more nuanced understanding of disease biology emerges, with potential implications for diagnostic stratification, prognostic assessment, and therapeutic innovation.

Cytoskeletal disorders affecting the nervous system are a diverse group of diseases that display a wide variety of clinical manifestations. Mutations in genes encoding cytoskeletal components disrupt the structural and functional integrity of this complex network, impairing normal development and function of the central and peripheral nervous systems. There are also certain diseases which lead to progressive neurodegeneration, and others which result from an interplay of multiple molecular pathways. This review outlines the primary cytoskeletal disorders affecting the nervous system. To provide a comprehensive overview, these diseases are categorized by their predominantly affected cytoskeletal component—namely microtubules, actin filaments, intermediate filaments, and cytoskeleton-associated proteins. Each category highlights the broader pathophysiological context of the underlying defect rather than an isolated structural disturbance. A deeper understanding of the complex pathophysiology of these disorders may contribute to the discovery of potential therapeutic targets, since current medical management primarily provides symptomatic relief or slows their progression.

The secondary sex ratio (SSR), defined as the ratio of male to female live births in a population, is a crucial indicator of reproductive and public health. External factors, such as lifestyle, natural disasters, environmental chemicals and infections, have been examined as potential trendsetters of the SSR. Several global challenges have emerged in recent years, such as climate change, wars, terrorist attacks and stressful political events. These aspects can potentially impact reproductive health outcomes, fertility rates, and the overall well-being of individuals. With respect to this, they may also affect the SSR. Through an in-depth examination of the existing literature, this manuscript elucidates the complex interconnections between global challenges and the SSR. Indeed, terrorist attacks and stressful political events have been linked to a decrease in the SSR. In contrast, high temperatures and warfare have shown a propensity to elevate the SSR in numerous scenarios. However, these associations require further validation through additional studies. The precise mechanisms through which these determinants exert their influence need to be elucidated. Understanding the unseen influences of global challenges on the SSR is crucial for understanding population trends and ensuring effective public health interventions.