Association Study between Per3 Gene Polymorphism and Diurnal Preference.
	    		
		   		
	    	
    	
    	
   		
        
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Seung Gul KANG
			        		
			        		;
		        		
		        		
		        		
			        		TaeYoung CHOI
			        		
			        		;
		        		
		        		
		        		
			        		Ho Kyoung YOON
			        		
			        		;
		        		
		        		
		        		
			        		Young Min PARK
			        		
			        		;
		        		
		        		
		        		
			        		Leen KIM
			        		
			        		;
		        		
		        		
		        		
			        		Heon Jeong LEE
			        		
			        		
		        		
		        		
		        		
		        		
		        		
			        		
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:Original Article
 
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		Diurnal preference;
			        		
			        		
			        		
				        		Polymorphism;
			        		
			        		
			        		
				        		PER3;
			        		
			        		
			        		
				        		Morningness
			        		
			        		
	        			
        			
        		
 
        	
            
            	- MeSH:
            	
	        			
	        				
	        				
				        		
					        		Alleles;
				        		
			        		
				        		
					        		Female;
				        		
			        		
				        		
					        		Genotype;
				        		
			        		
				        		
					        		Humans;
				        		
			        		
				        		
					        		Polymerase Chain Reaction
				        		
			        		
	        			
	        			
            	
            	
 
            
            
            	- From:Sleep Medicine and Psychophysiology
	            		
	            		 2011;18(1):35-39
	            	
            	
 
            
            
            	- CountryRepublic of Korea
 
            
            
            	- Language:Korean
 
            
            
            	- 
		        	Abstract:
			       	
			       		
				        
				        	OBJECTIVE: Diurnal preference is an attribute reflecting whether people are alert and preferring to be active either early or late in the day. It also referred to as chronotype or morningness-eveningness trait. The PER3 genes have been known to influence diurnal preference. In this study, we have investigated the associations between the PER3 gene polymorphisms and diurnal preference in a healthy young population, controlling for the social and environmental confounding factors. METHODS: The participants in this experiment included 299 unrelated medical college students (M=191, F=108), with a mean age of 22.9 years. Diurnal preference was measured by a single administration of the 13-item Composite Scale for Morningness (CSM). Genotyping of the PER3 VNTR (rs57875989) was performed using polymerase chain reaction. A two-tailed alpha of 0.05 was chosen. RESULTS: The mean+/-SD score on the CSM scale for all subjects was 31.90+/-6.39. There was no significant difference in total CSM score between gender groups, although females showed a trend towards higher morningness score. Although PER3 5R/5R showed the tendency towards high CSM scores, there were no significant differences on CSM scores among genotypes and allele status of PER3 VNTR (rs57875989). CONCLUSIONS: We could not confirm that the PER3 VNTR is associated with diurnal preference in a Korean healthy young population. The future studies need to investigate the association between diurnal preference and other polymorphisms of PER3 gene in larger sample of Korean young healthy population.