Possible association of a cholecystokinin promoter variant to schizophrenia.
Several lines of research indicate a cholecystokinin (CCK) deficit in schizophrenia patients. A C to T substitution was found in the promoter region of the CCK gene. We investigated this promoter variant in patients with schizophrenia and geographically-matchedcontrols. The T allele was detected in 24% of the 85 schizophrenics and 16% of the 247 controls. No significant difference in the T allele frequency was found between patients and controls (chi(2) = 2.77, P > 0.1). The schizophrenia sample was analyzed further along the dimensions of positive and negative symptoms. The patients with prominent negative symptoms presented a statistically significant association to the T allele (chi(2) = 4.13, P < 0.04). However, the significance disappeared after the Bonferroni correction (P > 0.15). Since the case-control analysis may present incorrect ethnic match between cases and controls, we applied the family-based tests to verify the above findings. Both transmission disequilibrium test (TDT; chi(2) = 5.33, P < 0.025 in 12 trios) and haplotype relative risk (HRR; chi(2) = 3.844, P < 0.05 in 60 trios) indicated a significantly high transmission of T allele to schizophrenia offspring probands from their parents. While our family-based tests seem to support the CCK involvement in schizophrenia, no definite conclusion can be drawn based on such a small sample size. This preliminary finding is subjected to future investigations.
Wang
Zhewu
Z
Mental Health Care Line, Cincinnati VA Medical Center, Cincinnati, Ohio 45220, USA. zhewu.wang2@med.va.gov
Wassink
Thomas
T
Andreasen
Nancy C
NC
Crowe
Raymond R
RR
D000483:Alleles; D002766:Cholecystokinin / Q000235:genetics*; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004252:DNA Mutational Analysis; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium; D010641:Phenotype; D017354:Point Mutation; D018807:Polymorphism, Single-Stranded Conformational; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012559:Schizophrenia / Q000235:genetics*
D004247:DNA; D002766:Cholecystokinin