Sleep disturbance associated with Smith-Magenis syndrome / 中华医学遗传学杂志

Smith-Magenis syndrome (SMS) (OMIM #182290) is a rare genetic disorder with a prevalence of 1 in 25 000 live births. Approximately 90% of SMS patients have harbored a 3.7 Mb interstitial 17p11.2 deletion involving the RAI1 gene, while 10% of cases have carried pathogenic variants of the RAI1 gene. SMS is characterized by sleep disturbance, intellectual impairment, developmental delay, craniofacial and cardiovascular anomalies, obesity, self injury, aggressive and autistic-like behaviors. Most SMS patients have sleep disorders such as short total sleep time, frequent night waking, short sleep onset, and early morning waking. The sleep disturbance may aggravate with age and persist throughout life. Three mechanisms have been delineated. The first concern was the abnormal secretion of melatonin, with high levels during daytime and low levels at night. Evaluation of the integrity of the intrinsically photosensitive retinal ganglion cell (ipRGC)/melanopsin system has found that SMS patients showed dysfunction in the sustained component of the pupillary light responses to blue light. Synchronization of daily melatonin profile and its photoinhibition are dependent on the activation of melanopsin. Dysfunction of the retina-melanin system may be one of the causes of melatonin spectrum disorders. Secondly, dysregulation of circadian rhythm gene expression has also been noted in mice and SMS patients. Finally, there may be association between sleep deprivation symptoms and DNA methylation patterns, which has provided new insights for SMS-associated sleep disorders and symptoms alike. Treatment for SMS-related sleep disorders is administered primarily through medications like melatonin tablets, which can alleviate insomnia-related sleep difficulties, in particular externalizing behavior in children. Researchers are also actively exploring other treatments for SMS currently.

Sueño en los trastornos del neurodesarrollo, déficit de atención e hiperactividad y en el espectro autista / Sleep in neurodevelopmental disorders

El sueño es uno de los actos fisiológicos más importantes para la estructuración funcional y anatómica de áreas del sistema nervioso central. Las alteraciones del sueño durante la infancia y su relación con trastornos del neurodesarrollo es compleja y sumam ente interesante, donde destaca la multiplicidad de causas de estos trastornos. Bajo esta premisa se realiza una revisión sobre las alteraciones del sueño en los trastornos del neurodesarrollo (TND), por déficit de atención e hiperactividad (TDAH) y del espectro autista (TEA). El sueño está presente desde la etapa fetal y va modificando su expresión en sintonía con la madurez del sistema nervioso central. Los trastornos del sueño y su relación con TDAH, TEA y otros TND son complejos, pero existen avances sobre la etiología de los mismos. Una mayor compresión de las funciones pleiotrópicas de los genes implicados en los trastornos del ciclo vigilia-sueño y en las desviaciones del desarrollo neurológico podría conducir a nuevas estrategias diagnósticas y terapéuticas de manera precoz con el fin de mejorar la calidad de vida del paciente, familiares y cuidadores.

The development and establishment of the normal sleep patterns are very important processes in the final anatomical and physiological architecture of the central nervous system. The relationship between sleep disturbances during childhood with neurodevelopmental disorders is complex and potentially synergistic. Sleep patterns are present since the fetal period but their structure and physiology is modified according with the maturation of the central nervous system. Sleep disorders and their relationship with attention deficit hyperactivity disorders(ADHD), autism spectrum disorders(ASD) and other neurodevelopmental disorders (TDN) are not well understood yet, but significant progresses have been made in understanding associations and potential etiological correlations. We reviewed sleep disturbances in NDT, in ADHD and in ASD. A greater understanding of the pleiotropic functions of the genes involved in sleep-wake cycle disorders and deviations from neurological developme nt could lead to new diagnostic and therapeut ic strategies in an early stage in order to improve the quality of life of the patient, relatives and caregivers.

Moléculas que marcam o tempo: implicações para os fenótipos circadianos / Timekeeping molecules: implications for circadian phenotypes

OBJETIVO: Revisar resumidamente a literatura dos últimos 36 anos de pesquisa em cronobiologia molecular a fim de informar aos profissionais de saúde os avanços obtidos nesta área e os potenciais para aplicação na clínica médica. MÉTODO: Buscas na literatura foram realizadas utilizando as bases de dados PubMed e Scopus usando como palavras-chave "clock genes, circadian rhythms, diurnal preference, delayed sleep phase syndrome, advanced sleep phase syndrome, photoperiod and mood disorder". DISCUSSÃO: Atualmente, o mecanismo molecular da regulação da ritmicidade circadiana é compreendido em grande detalhe. Muitos estudos publicados mostram associações de polimorfismos nos genes relógio com transtornos do ritmo circadiano e com transtornos do humor. CONCLUSÕES: De maneira geral, o progresso obtido na área de cronobiologia molecular traz um melhor entendimento da regulação do sistema de temporização biológico. O desenvolvimento de estudos nesta área tem o potencial de ser aplicável ao tratamento dos transtornos dos ritmos circadianos e certos transtornos do humor, além de prevenir riscos à saúde causados por viagens intercontinentais (Jet Lag) e por trabalhos noturnos e por turnos.

OBJECTIVE: The aim of this study was to review the molecular chronobiology studies in the last 36 years in order Eto point out the advances in this area to health professionals. METHOD: We searched in the PubMed and Scopus data banks for articles related with human molecular chronobiology. The keywords used were "clock genes, circadian rhythms, diurnal preference, delayed sleep phase syndrome, advanced sleep phase syndrome, photoperiod and mood disorder". DISCUSSION: The knowledge about molecular mechanism of circadian rhythms increased a lot in the last years and now we are able to better understand the details of molecular processes involved in circadian and sleep regulation. Studies show that polymorphisms in clock genes are associated with sleep and mood disorders. These studies will be helpful to further elucidate the regulation of molecular mechanisms of circadian rhythms. CONCLUSIONS: The development of these studies in molecular chronobiology can be helpful to treat circadian and mood disorders and to prevent health risks caused by intercontinental flights (Jet Lag), nocturnal or shift work schedule.

A genética dos distúrbios do sono na infância e adolescência: [revisão] / The genetics of sleep disorders in childhood and adolescence: [review]

OBJETIVO: O objetivo deste artigo é revisar a literatura sobre a genética dos distúrbios do sono na infância e adolescência. FONTES DOS DADOS: As palavras-chave "sono" e "genética" foram usadas para pesquisar por artigos publicados nos últimos cinco anos no banco de dados MEDLINE. A seguir, seus resumos foram analisados. A pesquisa também incluiu artigos clássicos, com a primeira descrição dos genes. SÍNTESE DOS DADOS: A recorrência familiar de muitos distúrbios do sono é um achado freqüente, mas loci genéticos foram descobertos para poucos deles. Descrevemos aqui distúrbios do sono transmitidos por herança genética e também aqueles que apresentam altos índices de recorrência familiar, apesar de nenhum gene específico haver sido encontrado. CONCLUSÕES: Apesar da maioria dos distúrbios do sono ainda não terem uma base molecular identificada, técnicas modernas são cada vez mais utilizadas para determinar a contribuição dos genes ao sono e aos seus distúrbios associados. A importância clínica destas descobertas pode estar relacionada com a melhoria de métodos diagnósticos, mas também como alvo para o desenvolvimento de medicações específicas.

OBJECTIVE: To review the literature regarding the genetics of sleep disorders in childhood and adolescence. SOURCES: Articles published in the past 5 years were searched on MEDLINE using the keywords sleep and genetics. Abstracts were then analyzed. Classical articles with the first description of genes were also included. SUMMARY OF THE FINDINGS: We often find familial recurrence in many sleep disorders. However, gene loci were discovered for only a few of them. We describe sleep disorders transmitted by genetic heritance and also those in that, although a gene was not found, familial recurrence is high. CONCLUSION: Although most of the sleep disorders do not have by now an identified molecular basis, modern techniques are being increasingly applied to determine the contribution of genes to sleep and its associated disorders. The clinical importance of these discoveries may relate not only to improving diagnostic methods but also as a target for drug development.