Association Studies of HSPA1A and HSPA1L Gene Polymorphisms With Schizophrenia in the Polish Population.

•Our study is the largest to date to evaluate the association between the variants of the HSPA1A and HSPA1L genes (rs562047, rs1008438, rs2075800) and the susceptibility to paranoid schizophrenia. It is worth to mention that rs1008438, rs2075800 variants have been examined in schizophrenia for the first time.•A sex-stratified analysis revealed haplotypic association with paranoid schizophrenia in men, albeit the risk effect was contributed only by a rare haplotypes.•More importantly, rs562047 variant was significantly associated with PANSS total and PANSS negative scores in schizophrenia.•Our results support previously reported associations between HSPA1A and HSPA1B SNPs and schizophrenia symptomatology.