Genetics of sleep disorders

Elucidating sleep disorders: a comprehensive bioinformatics analysis of functional gene sets and hub genes

Background

Sleep disorders (SD) are known to have a profound impact on human health and quality of life although their exact pathogenic mechanisms remain poorly understood.

Methods

The study first accessed SD datasets from the GEO and identified DEGs. These DEGs were then subjected to gene set enrichment analysis. Several advanced techniques, including the RF, SVM-RFE, PPI networks, and LASSO methodologies, were utilized to identify hub genes closely associated with SD. Additionally, the ssGSEA approach was employed to analyze immune cell infiltration and functional gene set scores in SD. DEGs were also scrutinized in relation to miRNA, and the DGIdb database was used to explore potential pharmacological treatments for SD. Furthermore, in an SD murine model, the expression levels of these hub genes were confirmed through RT-qPCR and Western Blot analyses.

Results

The findings of the study indicate that DEGs are significantly enriched in functions and pathways related to immune cell activity, stress response, and neural system regulation. The analysis of immunoinfiltration demonstrated a marked elevation in the levels of Activated CD4+ T cells and CD8+ T cells in the SD cohort, accompanied by a notable rise in Central memory CD4 T cells, Central memory CD8 T cells, and Natural killer T cells. Using machine learning algorithms, the study also identified hub genes closely associated with SD, including IPO9, RAP2A, DDX17, MBNL2, PIK3AP1, and ZNF385A. Based on these genes, an SD diagnostic model was constructed and its efficacy validated across multiple datasets. In the SD murine model, the mRNA and protein expressions of these 6 hub genes were found to be consistent with the results of the bioinformatics analysis.

Conclusion

In conclusion, this study identified 6 genes closely linked to SD, which may play pivotal roles in neural system development, the immune microenvironment, and inflammatory responses. Additionally, the key gene-based SD diagnostic model constructed in this study, validated on multiple datasets showed a high degree of reliability and accuracy, predicting its wide potential for clinical applications. However, limited by the range of data sources and sample size, this may affect the generalizability of the results.

Waking Up the Sleep Field: An Overview on the Implications of Genetics and Bioinformatics of Sleep

Sleep genetics is an intriguing, as yet less understood, understudied, emerging area of biological and medical discipline. A generalist may not be aware of the current status of the field given the variety of journals that have published studies on the genetics of sleep and the circadian clock over the years. For researchers venturing into this fascinating area, this review thus includes fundamental features of circadian rhythm and genetic variables impacting sleep-wake cycles. Sleep/wake pathway medication exposure and susceptibility are influenced by genetic variations, and the responsiveness of sleep-related medicines is influenced by several functional polymorphisms. This review highlights the features of the circadian timing system and then a genetic perspective on wakefulness and sleep, as well as the relationship between sleep genetics and sleep disorders. Neurotransmission genes, as well as circadian and sleep/wake receptors, exhibit functional variability. Experiments on animals and humans have shown that these genetic variants impact clock systems, signaling pathways, nature, amount, duration, type, intensity, quality, and quantity of sleep. In this regard, the overview covers research on sleep genetics, the genomic properties of several popular model species used in sleep studies, homologs of mammalian genes, sleep disorders, and related genes. In addition, the study includes a brief discussion of sleep, narcolepsy, and restless legs syndrome from the viewpoint of a model organism. It is suggested that the understanding of genetic clues on sleep function and sleep disorders may, in future, result in an evidence-based, personalized treatment of sleep disorders.

The Genetics of Sleep Disorders in Children: A Narrative Review

Sleep is a universal, highly preserved process, essential for human and animal life, whose complete functions are yet to be unravelled. Familial recurrence is acknowledged for some sleep disorders, but definite data are lacking for many of them. Genetic studies on sleep disorders have progressed from twin and family studies to candidate gene approaches to culminate in genome-wide association studies (GWAS). Several works disclosed that sleep-wake characteristics, in addition to electroencephalographic (EEG) sleep patterns, have a certain degree of heritability. Notwithstanding, it is rare for sleep disorders to be attributed to single gene defects because of the complexity of the brain network/pathways involved. Besides, the advancing insights in epigenetic gene-environment interactions add further complexity to understanding the genetic control of sleep and its disorders. This narrative review explores the current genetic knowledge in sleep disorders in children, following the International Classification of Sleep Disorders-Third Edition (ICSD-3) categorisation.

Disorders of sleep and circadian rhythms

Sleep is fundamental to the survival of humans. However, knowledge regarding the role of sleep and its regulation is poorly understood. Genetics in flies, mice, and humans has led to a detailed understanding of some aspects of circadian regulation. Sleep homeostasis (the effect of increasing periods of wakefulness on our sleep propensity) is largely not understood. Sleep homeostasis is distinct from, but also linked to, the circadian clock. It is only in the last two decades that our understanding of some sleep disorders has been revealed. These breakthroughs were mostly fueled by intensive investigation using genetic tools. Although modern human genetics has revolutionized scientific research of neurologic disorders beginning ~35 years ago, studies of sleep and sleep disorders have lagged behind those of many neurologic diseases. This is due to the complexity in phenotyping behaviors like sleep and the fact that sleep is strongly influenced by environmental and other factors. We have long been aware that the amount of sleep required by individuals is normally distributed in the general population with small proportions of people being natural short or natural long sleepers. However, it has been less than a decade since Mendelian families of natural short sleepers have been recognized. Recent work has made significant advances and mechanistic insights of several sleep disorders as well as familial natural short sleepers by using ever-improving human genetic and cellular molecular tools. Given recent advances into genetic and biologic understanding of sleep, the hope of understanding this indispensable process is closer. Ultimately, our growing understanding will lead to more effective treatments of human sleep disorders.

Genetic and immunologic aspects of sleep and sleep disorders

The study of genetics is providing new and exciting insights into the pathogenesis, diagnosis, and treatment of disease. Both normal sleep and several types of sleep disturbances have been found to have significant genetic influences, as have traits of normal sleep, such as those evident in EEG patterns and the circadian sleep-wake cycle. The circadian sleep-wake cycle is based on a complex feedback loop of genetic transcription over a 24-h cycle. Restless legs syndrome (RLS) and periodic limb movements in sleep (PLMS) have familial aggregation, and several genes have a strong association with them. Recent genome-wide association studies have identified single nucleotide polymorphisms linked to RLS/PLMS, although none has a definite functional correlation. Narcolepsy/cataplexy are associated with HLA DQB1*0602 and a T-cell receptor α locus, although functional correlations have not been evident. Obstructive sleep apnea is a complex disorder involving multiple traits, such as anatomy of the oropharynx, ventilatory control, and traits associated with obesity. Although there is clear evidence of familial aggregation in the obstructive sleep apnea syndrome, no specific gene or locus has been identified for it. Angiotensin-converting enzyme has been proposed as a risk variant, but evidence is weak. Fatal familial insomnia and advanced sleep phase syndrome are sleep disorders with a definite genetic basis.

Biomarkers: symptoms, survivorship, and quality of life

OBJECTIVES

To review the evidence on a number of biomarkers that show potential clinical utility in the prediction of and treatment responsiveness for the four most common symptoms associated with cancer and its treatment (ie, pain, fatigue, sleep disturbance, depression).

DATA SOURCES

Review and synthesis of review articles and data-based publications.

CONCLUSION

A growing body of evidence suggests that sensitive and specific biomarkers will be available to assist clinicians with the assessment and management of symptoms.

IMPLICATIONS FOR NURSING PRACTICE

Nurses will play a critical role in educating patients about their risk for specific symptoms based on an evaluation of specific biomarkers. Nurses will be involved in using biomarker data to titrate medications based on patient's responses to symptom management interventions.