Association between the angiotensin‐converting enzyme gene insertion/deletion polymorphism and first‐episode patients with schizophrenia in a Chinese Han population

Background Angiotensin‐converting enzyme (ACE), a key enzyme of the renin–angiotensin system, can modulate dopamine turnover in the midbrain. Previous studies have revealed an association between ACE gene insertion/deletion (I/D) polymorphism and chronic schizophrenia, yet results are conflicting. Objective The primary objective of this study was to examine whether the ACE gene I/D polymorphism is associated with first‐episode patients with schizophrenia (FEP) in a Chinese Han population. Methods The presence of the polymorphism was determined in 220 FEP and 538 healthy controls using a case–control design. We assessed the psychopathology in 212 FEP using the Positive and Negative Syndrome Scale (PANSS). Results The allelic and genotypic frequencies of the ACE gene I/D polymorphism did not significantly differ between FEP and healthy controls (both p  > 0.05). However, the negative PANSS symptom was significantly higher in FEP with the D/D genotype than those with I/D and I/I genotypes (all p  < 0.05) even after Bonferroni corrections (all p  < 0.05). Furthermore, the D allele of the ACE gene was associated with higher negative PANSS symptom score in FEP. Conclusions Our results indicated that even though the ACE gene I/D polymorphism did not associate with FEP, it may play a role in susceptibility to the negative PANSS symptom of FEP in a Chinese Han population. Copyright © 2014 John Wiley & Sons, Ltd.