Polymorphism of the Cldn5 Gene and Schizophrenia in An Iranian Population

Background: the gene coding claudin (cldn5) is located on 22q11. since the proteins of cldn5 family are a ma-jor component for barrier-forming tight junctions,it may be important to test whether or not the cldn5 locus could be associated with schizophrenia. methods: a total of 150 individuals affected with schizophrenia and 150 healthy persons were recruited. the relation-ship between the three single nucleotide polymorphism (snps) and schizophrenia disease was studied using polymer-ase chain reaction (pcr)-based restriction fragment length polymorphism (rflp) technique. the pcr products were completely digested with restriction enzymes of dpnii,pvuii and bstni,and then separated on agarose gel. the statis-tical investigations and haplotype analysis were also performed. results: the transmission disequilibrium test (tdt) exhibited weak association between rs10314 [c/g] and schizo-phrenia (v2 = 3.55,p = 0.022),but the other two snps did not show such an association. the global chi-square test showed that the 3-snp haplotype system was not associated with schizophrenia although the 1-df test for individual haplotypes showed that the rs1548359(c)-rs10314(g)-rs739371(c) haplotype was excessively non-transmitted (v2 = 6.33,p = 0.025). the v2 test for ld between snps indicated that these three snps were in strong ld. conclusion: collectively,ld analysis showed that the cldn5 locus was associated with schizophrenia in an iranian population.