Table 2. Characteristic of the included studies about the associations between 5-HTT, LEPR polymorphisms and OSAS risk.

	Author	Year	Country	Age(Case/Control)	AHI(Case/Control)		Case/Control	Diagnosis	Genotype Method	Genotype Frequency
										Genotype	OSAS	Control
5-HTT	Chen, et al	2013	China	43.8±3.0⊢		42.6±14.8⊢	121/105	PSG AHI ≥5 events/h	PCR)	SS	59	55
LPR				43.0±2.7⊤		3.7±1.3⊤		AHI ≥15 events/h		SL	35	34
										LL	27	16
	Ylmaz, et al	2005	Turkey	NA		NS	42/162	PSG	PCR	SS	6	60
				NA		NS				SL	16	71
										LL	4	35
	Yue, et al	2008	China	45.2±11.8		53.9±16.4	254/338	PSG AHI ≥5 events/h	PCR	SS	114	173
				43.2±12.7		NS				SL	106	131
										LL	34	34
	Yue, et al	2005	China	42.3±10.1		NS	104/150	PSG AHI ≥10 events/h	PCR	SS	51	78
				NA		NS				SL	33	54
										LL	20	18
5-HTT	Chen, et al	2013	China	43.8±3.0		42.6±14.8	121/105	PSG AHI ≥5 events/h	PCR	10/10	8	1
VNTR				43.0±2.7		3.7±1.3		AHI ≥15 events/h		10/12	24	10
										12/12	89	94
	Ylmaz, et al	2005	Turkey	NA		NS	42/162	PSG	PCR	10/10	3	14
				NA		NS				10/12	13	61
										12/12	9	93
	Yue, et al	2008	China	45.2±11.8		53.9±16.4	254/338	PSG AHI ≥5 events/h	PCR	10/10	6	3
				43.2±12.7		NS				10/12	46	41
										12/12	202	294
	Yue, et al	2005	China	42.3±10.1		NS	104/150	PSG AHI ≥10 events/h	PCR	10/10	3	1
				NA		NS				10/12	20	14
										12/12	81	135
LEPR	Popko, et al	2007	Poland	21–77		>5	102/77	PSG AHI ≥5 events/h	PCR assay	Gln/Gln	18	26
				18–65		<5				Gln/Arg	61	40
										Arg/Arg	23	11
	Hanaoka,	2008	Japan	50.3±2.0		49.1±3.9	130/50	PSG AHI ≥10 events/h	PCR	Gln/Gln	63	21
	et al			50.0±4.4		2.1±0.5				Gln/Arg	57	28
										Arg/Arg	5	1
	Huang,	2003	China	43.4±0.8		NS	60/40	PSG	PCR-RFLP	Gln/Gln	79	64
	et al			43,9±1.2		NS				Gln/Arg	22	23
										Arg/Arg	2	1

NS: None Stated.

⊢: Indicated age of OSAS patients group in these studies.

⊤: Indicated age of Control group in these studies.