Examination of the gene CALHM1 (Calcium Homeostasis Modulator Factor) in terms of SNPS (Mutation/Polymorphism) in patients with bipolar disorder (BD)

Bipolar disorder is a psychiatric disease with the periods of mania/hypomania and depression and showing genetic transition. It has been seen 1,3 % in population. Bipolar disorder type 1 is seen in women and men in same frequencies. Bipolar disorder type 2 is more common in women than men. Etiology of this disorder hasn't been clearly shown yet. Our aim is to study in terms of mutations and polymorphisms of CALHM1 (calcium homeostasis modulator factor 1) gene which we think can cause bipolar disorder and if possible is to interpret association with disorder. Our hypothesis is, ' Mutation or polymorphisms that might affect the function of CALHM1 gene product which exist in endoplasmic reticulum membrane and cell membrane and plays an important role on modulating calcium homeostasis in cells can be related to bipolar disorder'. 40 patients which have been diagnosed according to bipolar disorder diagnosis criteria of DSM-IV-TR, their 10 first degree-relatives and 39 healthy controls are being taken to study for exon 1. 40 patients, their 10 first degree-relatives and 38 healthy controls are being taken to study for exon 2. DNA isolation was carried out from blood obtained from each subject. DNA sequence analysis was performed being amplified first and second exons of CALHM1 gene by PCR. SNP's located on these exons were examined by Mutation Surveyor V4.0.9 programme. Statistical analysis was carried out by using SHEsis programme. 15 numbers of SNPs including six numbers of identified SNPs and nine numbers of novel SNPs in this gene was determined. Of these SNPs, allele frequency of 360G>GA SNP indicated a significant difference between case and control groups. SNPs which were most frequently seen and had a highest MAF value in this study were rs729211 and rs4918016. 360G>GA SNP causes amino acid alteration in protein. However, sample group must be expanded to show that this SNP affects a function of CALHM1 protein in patients with bipolar disorder. Keywords: Bipolar disorder, CALHM1, SNP