ABSTRACT
Objective To explore the relationship of miR-34b/c gene polymorphisms and event-related potential P300 in major depressive disorder.Methods The design of case-control research was used,and 302 major depressive patients and 327 normal controls who were in age and gender matched with patients were measured auditory event-related potential P300 on the day when two groups were collected.Polymerase chain reaction(PCR) and direct DNA sequencing technology were used to detect miR-34b/c gene polymorphisms.Results (1) In the single locus analysis,the rs4938723,rs2187473 and rs28757623 had no significant difference in allele frequency and genotype frequency between depressive patients and controls (P＞ 0.05);Haplotype C-C-C in rs4938723-rs2187473-rs28757623 was statistically significant different in depressive patients and controls(x2 =3.96,P=0.046).The odds ratio (OR) was 1.322(95％CI=1.004-1.740).(2) Compared with normal controls,P300 of the patients with major depressive disorder had longer latency of N2 (P＜0.01),P3a (P＜0.01) and P3b (P＜0.05).(3) The P300 targets of major depressive disorder had statistical difference(P＜0.05)in rs28757623 between the individuals with the G allele genotype and C/C genotype.The latency of N1 ((90.80±28.62) ms),P3a((281.79±37.89) ms),P3b((323.87±41.17) ms) were longer thanC/C genotype ((77.40 ± 20.96) ms,(253.00 ± 34.36) ms,(297.30± 23.70) ms).Conclusion Rs4938723-rs2187473-rs28757623 haplotype CCC in miR-34b/c gene might be risk factor for the onset of depression,miR-34b/c gene rs28757623 polymorphism is associated with the principal component of P300 latency in patients with Major depressive disorder which suggest that genetic factors may have a certain impact on cognitive function in the patients with major depressive disorder.