OBJECTIVETo have a better understanding of genetic contributions to the development of obstructive sleep apnea hypopnea syndrome (OSAHS) by reviewing studies on its genetic basis.

DATA SOURCESA comprehensive search of the PubMed literature without restriction on the publication date was carried out using terms "obstructive sleep apnea" and "candidate genes" or "genetics".

STUDY SELECTIONArticles were selected if they were an original research paper or meta analysis of the genetic factors of OSAHS.

RESULTSFour intermediate phenotypes were described and several candidate genes that may determine the expression and severity of OSAHS were reviewed.

CONCLUSIONMultiple gene-gene interactions occurring in genes that affect obesity, craniofacial structure, ventilator control and asleep-awake pattern may influence the expression of OSAHS in a suitable environment.

Humans ; Obesity ; genetics ; Sleep Apnea, Obstructive ; genetics

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.
Animals ; Circadian Rhythm ; Humans ; Melatonin ; Mice ; Sleep ; Sleep Wake Disorders/genetics* ; Smith-Magenis Syndrome/genetics*

Circadian rhythm disorder is a common society issue caused by jet lag,shift work,sleep disruption and changes in food consumption. Light is the major factor affecting the circadian rhythm system. Disruption of the circadian rhythm system can cause damage to the body,leading to some diseases. Maintaining a normal circadian system is of great importance for good health. Ideal therapeutic effect can not only alleviate symptoms of the diseases,but also recovery the disturbed circadian rhythm to normal. The paper summarizes the modeling methods of animal circadian rhythm disorder,diseases of circadian rhythm abnormality,regulation of circadian clock genes and medicine which are related to circadian rhythm to diseases of circadian rhythm disorder.
Animals ; Circadian Rhythm/genetics* ; Humans ; Jet Lag Syndrome/genetics* ; Sleep ; Sleep Disorders, Circadian Rhythm

Sleep has attracted extensive attention due to its significance in health. However, its association with erectile dysfunction (ED) is insufficiently investigated. To investigate the potential causal links between sleep traits (insomnia, sleep duration, and chronotype) and ED, this study was performed. The single-nucleotide polymorphisms (SNPs) associated with insomnia, sleep duration, and chronotype were retrieved from previous genome-wide association studies (GWAS). A conventional two-sample Mendelian randomization (MR) was used to estimate the causal links between sleep traits and ED. The summary statistics of ED were from individuals of European ancestry (6175 cases vs 217 630 controls). As shown by the random effect inverse-variance-weighting (IVW) estimator, genetically predicted insomnia was causally associated with a 1.15-fold risk of ED (95% confidence interval: 1.07-1.23, P < 0.001). Sleep duration and morningness were not causally associated with ED, as indicated by the IVW (all P > 0.05). These findings were consistent with the results of sensitivity analyses. Based on genetic data, this study provides causal evidence that genetically predicted insomnia increases the risk of ED, whereas sleep duration and chronotype do not.
Male ; Humans ; Sleep Initiation and Maintenance Disorders/genetics* ; Genome-Wide Association Study ; Erectile Dysfunction/genetics* ; Sleep/genetics* ; Phenotype ; Polymorphism, Single Nucleotide

Humans ; Genome-Wide Association Study ; Sleep Apnea, Obstructive/genetics*

OBJECTIVE: To study the trinucleotide repeats of GCN (GCA, GCT, GCC, GCG) encoding Alanine in exon 3 of the PHOX2B gene among healthy individuals from southwest China and two patients with Congenital central hypoventilation syndrome (CCHS). METHODS: The number and sequence of the GCN repeats of the PHOX2B gene were analyzed by capillary electrophoresis, Sanger sequencing and cloning sequencing of 518 healthy individuals and two newborns with CCHS, respectively. RESULTS: Among the 1036 alleles of the 518 healthy individuals, five alleles were identified, including (GCN)₇, (GCN)₁₃, (GCN)₁₄, (GCN)₁₅ and (GCN)₂₀. The frequency of the (GCN)₂₀ allele was the highest (94.79%). And five genotypes were identified, which included (GCN)₇/(GCN)₂₀, (GCN)_13/(GCN)₂₀, (GCN)₁₄/(GCN)₂₀, (GCN)₁₅/(GCN)₂₀, (GCN)₂₀/(GCN)₂₀. The homozygous genotypes were all (GCN)₂₀/(GCN)₂₀, and the carrier rate was 89.58%. Four GCN sequences of the (GCN)₂₀ homozygous genotypes were identified among the 464 healthy individuals. The GCN repeat numbers in the exon 3 of the PHOX2B gene showed no significant difference between the expected and observed values, and had fulfilled the,Hardy-Weinberg equilibrium. The genotypes of the two CCHS patients were (GCN)₂₀/(GCN)₂₅ and (GCN)₂₀/(GCN)₃₀, respectively. CONCLUSION It is important to determine the GCN repeats and genotypic data of the exon 3 of the PHOX2B gene among the healthy individuals. The number of GCN repeats in 518 healthy individuals was all below 20. The selection of appropriate methods can accurately detect the polyalanine repeat mutations (PARMs) of the PHOX2B gene, which is conducive to the early diagnosis, intervention and treatment of CCHS.
Humans ; Infant, Newborn ; Homeodomain Proteins/genetics* ; Hypoventilation/congenital* ; Mutation ; Sleep Apnea, Central/genetics* ; Transcription Factors/genetics*

OBJECTIVE To report on the phenotype of an infant with central hypoventilation syndrome (CCHS) and result of PHOX2B gene mutation analysis for the purpose of genetic counseling and prenatal diagnosis. METHODS Clinical data of an infant with CCHS was collected and analyzed. Potential mutation of PHOX2B gene was analyzed by amplified fragment length polymorphism (amp-FLP) and DNA sequencing. RESULTS The patient had typical clinical features of CCHS including frequent hypoventilation during sleeping, hypoxemia and hypercapnia which could be corrected by continuous ventilatory support. She also had repeated bruising and was difficult-to-wean, but without any cardiac, pulmonary, neuromuscular or brainstem lesions. DNA sequencing and amp-FLP of the PHOX2B gene showed that the patient has carried a polyalanine expansion repeat mutation (PARM) in exon 3. A 27 bp duplication was confirmed in the repeat sequence of 20 alanines by cloned and sequenced. This has led to an expansion of the repeat tract to 29 alanines. The genotype was therefore 20/29. CONCLUSION A patient with CCHS has been described. Mutation screening of PHOX2B gene can be used as an important support for diagnosis and genetic counseling for such patients.
Female ; Homeodomain Proteins ; genetics ; Humans ; Hypoventilation ; congenital ; genetics ; Infant, Newborn ; Mutation ; Sleep Apnea, Central ; genetics ; Transcription Factors ; genetics

Child ; Child, Preschool ; Female ; Humans ; Male ; Peptidyl-Dipeptidase A ; genetics ; Polymorphism, Genetic ; Sleep Apnea, Obstructive ; genetics ; physiopathology

OBJECTIVE: To explore the relationship between sleep habits (sleep duration, sleep efficiency, sleep onset timing) and ischemic stroke, and whether there is an interaction between sleep habits and ischemic stroke susceptibility gene loci. METHODS: A questionnaire survey, physical examination, blood biochemical testing and genotyping were conducted among rural residents in Beijing, and the gene loci of ischemic stroke suggested by previous genome-wide association studies (GWAS) were screened. Multivariable generalized linear model was used to analyze the correlation between sleep habits, sleep-gene interaction and ischemic stroke. RESULTS: A total of 4 648 subjects with an average age of (58.5±8.7) years were enrolled, including 1 316 patients with ischemic stroke. Compared with non-stroke patients, stroke patients with sleep duration ≥9 hours, sleep efficiency < 80%, and sleep onset timing earlier than 22:00 accounted for a higher proportion (P < 0.05). There was no significant association between sleep duration and risk of ischemic stroke (OR=1.04, 95%CI: 0.99-1.10, P=0.085). Sleep efficiency was inversely associated with the risk of ischemic stroke (OR=0.18, 95%CI: 0.06-0.53, P=0.002). The risk of ischemic stroke in the subjects with sleep efficiency < 80% was 1.47-fold (95%CI: 1.03-2.10, P=0.033) of that in the subjects with sleep efficiency ≥80%. Falling asleep earlier than 22:00 was associated with 1.26 times greater risk of stroke than falling asleep between 22:00 and 22:59 (95%CI: 1.04-1.52, P=0.017). Multifactorial adjustment model showed that rs579459 on ABO gene had an interaction with sleep time (P for interaction =0.040). When there were two T alleles for rs579459 on the ABO gene, those who fell asleep before 22:00 had 1.56 times (95%CI: 1.20-2.04, P=0.001) the risk of stroke compared with those who fell asleep between 22:00 and 22:59, and there was no significant difference when the number of pathogenic alleles was 0 or 1. In the model adjusted only for gender, age and family structure, sleep duration and the number of T allele rs2634074 on PITX2 gene had an interaction with ischemic stroke (P for interaction=0.033). CONCLUSION Decreased sleep efficiency is associated with increased risk of ischemic stroke, and falling asleep earlier than 22:00 is associated with higher risk of ischemic stroke. Sleep onset timing interacted with rs579459 in ABO gene and the risk of ischemic stroke. Sleep duration and PITX2 rs2634074 may have a potential interaction with ischemic stroke risk.
Aged ; Genome-Wide Association Study ; Humans ; Ischemic Stroke ; Middle Aged ; Sleep/genetics* ; Stroke/genetics* ; Surveys and Questionnaires

OBJECTIVETo observe the expression of cannabinoid receptor 1 (CB1R) mRNA and pathological changes in rat hippocampus after deprivation of rapid eye movement (REM) sleep.

METHODSTotally 42 Sprague-Dawley male rats were randomly divided into cage control (CC), tank control (TC) and the sleep deprivation groups (SD). The SD and TC rats were sacrificed at the end of 1 d, 3 d and 5 d sleep deprivation periods, respectively. The modified multiple platform methods were established for the REM sleep deprivation. CB1R mRNA was measured by reverse transcription-polymerase chain reaction (RT-PCR). The hippocampus sections of different stages were observed with electron microscope.

RESULTIn SD 1 d group, the expression of CB1R mRNA was significantly increased compared with the CC, TC, SD 3 d and SD 5 d groups (P <0.05) while in SD 3 d group it was reduced. The expression of CB1R mRNA of SD 5 d group was significantly higher than that of the SD 3 d group (P <0.05). Neuron apoptosis was found in SD 3 d and SD 5 d groups.

CONCLUSIONSleep deprivation can cause brain injury with the changes of CB1R mRNA expression.

Animals ; Hippocampus ; metabolism ; ultrastructure ; Male ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptor, Cannabinoid, CB1 ; biosynthesis ; genetics ; Sleep Deprivation ; metabolism ; pathology ; Sleep, REM