D3 dopamine receptor gene Ser9Gly polymorphism in Russian patients with schizophrenia

Polymorphic marker Ser9GIy of dopamine receptor D3 gene is considered perspective for associative studies of schizophrenia. Allele and genotype frequency of this polymorphism were studied in different ethnic groups of schizophrenic patients as well as the attempts have been made to reveal an association with clinical presentations of the disease. However, the results are inconsistent. The present study aimed at investigating Ser9GIy DRD3 gene polymorphism in Russian sample of schizophrenic patients. One hundred and fifty patients with ICD-10 diagnosis of schizophrenia (broad definition), 69 male and 81 female, aged 34,8 13,87 years, age at disease onset 24,3 9 years, have been examined. Control group consisted of 150 healthy subjects without family history of schizophrenia, 60 male and 90 female, aged 32,7 +/- 13.5 years. No between-group differences have been found for Ser9Gly DRD3 allele and genotype frequencies. However, a frequency of homozygous genotype Gly/Gly was significantly higher in female patients, comparing to female controls (p=0,038 Yate's corrected, OR 9. CI 0,95% 1,0-79,5). A role of sex-dependent association between Ser9GIy DRD3 polymorphism and schizophrenia is discussed.