Interleukin-1 receptor antagonist (IL-1RA) and interleukin-4 (IL-4) variable number of tandem repeat polymorphisms in schizophrenia and bipolar disorder: an association study in Turkish population

Pehlivan S., Oyaci Y., Tuncel F. C., Aytac H. M.

EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS, vol.23, no.1, 2022 (ESCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 23 Issue: 1
  • Publication Date: 2022
  • Doi Number: 10.1186/s43042-022-00341-6
  • Journal Name: EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS
  • Journal Indexes: Emerging Sources Citation Index (ESCI), Scopus, Academic Search Premier, Arab World Research Source, EMBASE, Directory of Open Access Journals
  • Keywords: Schizophrenia, Bipolar disorder, Inflammation, IL-1RA, IL-4, VNTR, 3 VNTR POLYMORPHISM, GENE POLYMORPHISM, SUSCEPTIBILITY LOCI, CYTOKINES, FAMILIES, DISEASE, COMPLEX, RISK
  • Istanbul University Affiliated: Yes

Abstract

Background Pro-inflammatory/anti-inflammatory cytokine imbalance in cerebrospinal fluid or plasma of schizophrenia (SCZ) and bipolar disorder (BD) patients has been documented over the last decade. We aim to examine the interleukin-1 receptor antagonist (IL-1RA) and IL-4 variable number of tandem repeat (VNTR) polymorphisms in SCZ and BD patients by comparing them with healthy controls. Methods Two hundred and thirty-four unrelated patients (127 patients with SCZ, 107 patients with BD) and 204 healthy controls were included. The Structured Clinical Interview for DSM-IV Axis I Disorders was used to confirm the diagnosis. In addition, the polymerase chain reaction technique was used to investigate IL-1RA and IL-4 VNTR polymorphisms. Results Our results showed that the distributions of IL-1RA and IL-4 genotype and the allele frequencies of SCZ or BD patients were not significantly different from the healthy control group. IL-1RA allele 2 homozygous genotype and IL-1RA allele 2 frequencies were non-significantly higher among SCZ patients than in controls. Conclusions Our study indicates that the IL-1RA and IL-4 VNTR polymorphisms are not considered risk factors for developing SCZ and BD among Turkish patients.