[The association between polymorphism of the serotonin 2A, 2C receptor genes and obstructive sleep apnea-hypopnea syndrome in Han population].

OBJECTIVE To investigate the association between polymorphisms of the serotonin 2A, 2C receptor genes and obstructive sleep apnea-hypopnea syndrome (OSAHS), and therefore to explore the genotypes related to OSAHS. METHODS The T102C and A1438G polymorphisms of the serotonin 2A receptor genes and the G796C polymorphisms of the serotonin 2C receptor genes were identified by polymerase chain reaction-restricted fragment length polymorphism assay in 119 unrelated subjects (including 65 OSAHS patients and 54 normal controls) of "Han" population of China. The genotype distribution and the allele frequencies of the polymorphisms were compared between the OSAHS group and the control group. The effects of polymorphisms in the OSAHS group on parameters of polysomnography and indexes correlated with obesity were analyzed. RESULTS There was no significant difference in genotype distribution and allele frequencies of the T102C polymorphisms of the serotonin 2A receptor genes between the two groups; the frequencies of TT/TC/CC genotype and T/C allele were 27.7% (18/65), 46.2% (30/65), 26.1% (17/65), 50.8% (66/130) and 49.2% (64/130), respectively in the OSAHS group; but were 27.8% (15/54), 51.8% (28/54), 20.4% (11/54), 53.7% (58/108) and 46.3% (50/108), respectively in the control group (chi(2) = 0.616 and 0.203, respectively, P > 0.05). The G796C polymorphisms of the serotonin 2C receptor genes were as follows: the frequencies of male's G/C allele, female's GG/GC genotype and G/C allele were 88.9% (48/54), 11.1% (6/54), 63.6% (7/11), 36.4% (4/11), 81.8% (18/22) and 18.2% (4/22), respectively in the OSAHS group; but were 90.5% (38/42), 9.5% (4/42), 66.7% (8/12), 33.3% (4/12), 83.3% (20/24) and 16.7% (4/24), respectively in the control group (chi(2) = 0.007, 0.002 and 0.064, respectively, P > 0.05). The frequencies of AA genotype and A allele in the A1438G polymorphisms of the serotonin 2A receptor genes in the OSAHS group [63.1% (41/65) and 74.6% (97/130), respectively] were significantly higher than those of the control one [27.8% (15/54) and 40.7% (44/108), respectively; chi(2) = 18.779 and 28.035, respectively, P < 0.01]. The OSAHS patients with AA genotype had higher obstructive apnea-hypopnea index (OAHI) and longest apnea time (LAT) than those with AG/GG genotype [OAHI were (40 +/- 9)/h, (25 +/- 9)/h and (20 +/- 11)/h, respectively, t = 6.674 and 7.753, respectively, P < 0.05; LAT were (94 +/- 10) s, (88 +/- 9) s and (75 +/- 12) s, respectively, t = 3.278 and 5.682, respectively, P < 0.05]. The lowest saturation of blood oxygen in patients with AA genotype was significantly lower than that in patients with AG/GG genotype [(69 +/- 12)%, (78 +/- 10)% and (80 +/- 9)%, respectively, t = 4.025 and 4.153, respectively, P < 0.05]. There was no significant difference in body mass index [(26.9 +/- 2.8) kg/m(2), (25.2 +/- 2.7) kg/m(2) and (26.0 +/- 3.7) kg/m(2), respectively], neck circumference [(43.3 +/- 2.7) cm, (42.6 +/- 1.8) cm and (42.8 +/- 2.1) cm, respectively] and waist/hip rate (0.89 +/- 0.12), (0.92 +/- 0.11) and (0.90 +/- 0.09), respectively, F = 0.859, 1.296 and 1.078, respectively, P > 0.05). CONCLUSION The T102C polymorphisms of the serotonin 2A receptor gene and the G796C polymorphisms of the serotonin 2C receptor gene may be not associated with OSAHS in subjects of "Han" population of China. The 1438 AA genotype of the serotonin 2A receptor gene may be involved in OSAHS, and the A allele may be an important candidate gene for OSAHS.