title: Association of single-nucleotide polymorphism of cholecystokinin receptor A gene with schizophrenia in an Eastern Indian population.
abstract: BACKGROUND
  Cholecystokinin A receptor (CCK-AR) gene polymorphism is being increasingly reported in schizophrenia. It varies among different population groups but is associated with several complications of schizophrenia.
  
  
  OBJECTIVE
  The present study was undertaken to assess whether the CCK-AR polymorphism is stabilized and is more consistently associated with schizophrenia in an Eastern Indian sub-population.
  
  
  METHODS
  It was carried out as a cross-sectional, observational, hospital-based study on 95 schizophrenia patients and 138 control subjects selected by the method of convenience.
  
  
  METHODS
  Single-nucleotide polymorphisms located in the regulatory region of the CCK-AR gene were assessed by restriction fragment length polymorphism (RFLP) in the polymerase chain reaction (PCR) amplified product of CCK-AR gene in study subjects. RFLP was done by the digestion of the PCR product by the restriction enzyme Pst-1 followed by gel electrophoresis.
  
  
  METHODS
  Assessment of the stability of C/T polymorphism in the study population was done by applying Hardy-Weinberg equilibrium rule. The significance of difference in the allelic distribution between case and controls was analyzed by Chi-square (χ(2)) test and odds ratio (OR) analysis.
  
  
  RESULTS
  CCK-R polymorphism was in Hardy-Weinberg equilibrium in both groups. Distribution of the C allele of this gene was significantly higher in schizophrenia patients (χ(2) = 4.35, OR = 1.51; confidence interval at 95% =1.04-2.20).
  
  
  CONCLUSIONS
  C/T polymorphism of the CCK-R gene is a stable polymorphism in our study population. Moreover, the C allele is significantly more abundant in schizophrenia patients imparting them a greater risk of development of complications like auditory hallucination.
authors.affiliation: Department of Biochemistry, R. G. Kar Medical College, Kolkata, West Bengal, India.
authors.forename: Jayanta K
authors.initials: JK
authors.lastname: Rout
authors.affiliation: Department of Biochemistry, Calcutta National Medical College, Kolkata, West Bengal, India.
authors.forename: Anindya
authors.initials: A
authors.lastname: Dasgupta
authors.affiliation: Department of Psychiatry, N R S Medical College, Kolkata, West Bengal, India.
authors.forename: Omprakash
authors.initials: O
authors.lastname: Singh
authors.affiliation: Department of Biochemistry, Calcutta National Medical College, Kolkata, West Bengal, India.
authors.forename: Ushasi
authors.initials: U
authors.lastname: Banerjee
authors.affiliation: Department of Zoology, University of Burdwan, Burdwan, West Bengal, India.
authors.forename: Anupam
authors.initials: A
authors.lastname: Basu
keywords: Cholecystokinin A receptor polymorphism; Hardy–Weinberg equilibrium; restriction fragment length polymorphism; schizophrenia