Association study of suppressor with morphogenetic effect on genitalia protein 6 (SMG6) polymorphisms and schizophrenia symptoms in the Han Chinese population

Aim Schizophrenia (SZ) is a complex psychiatric disorder that has a genetic component. Suppressor with morphogenetic effect on genitalia protein 6 (SMG6) encodes a protein that is involved in the nonsense-mediated mRNA decay pathway; the gene is located in the lissencephaly critical region of chromosome 17p13.3 that is linked to neuronal migration, the disturbance of which has been implicated in SZ pathogenesis. Several studies have found that SMG6 is associated with SZ. The present case–control study sought to identify SMG6 gene polymorphisms that may confer susceptibility to SZ in a Han Chinese population. Methods Paranoid SZ patients and control subjects (n=528 each) were genotyped for three single nucleotide polymorphisms. Genotype was determined by real-time polymerase chain reaction. SZ symptoms were evaluated by the Positive and Negative Symptom Scale. Results Significant associations were observed in genotypes between SZ and controls at rs1885986 (χ2 = 8.89; P=0.011), in alleles in females at rs1885986 (χ2 = 4.59; P = 0.032), and in genotypes between males and females at rs1885986 (χ2=6.55 and 32.92, P=0.037 and 7.47×10−8, respectively). In addition, rs216193 was significantly associated with total Positive and Negative Syndrome Score and positive symptom subscore in SZ (F=9.79 and 9.69, P=0.000 and 0.000, respectively). Conclusions These results provide evidence for an association between SMG6 polymorphisms and SZ susceptibility and symptoms in the Han Chinese population.