title: Paraoxonase polymorphism in northwestern Indians.
abstract: OBJECTIVE
  The aim of this study was to distinguish paraoxonase phenotypes by dual substrate method.
  
  
  METHODS
  166 unrelated healthy northwestern Indian Punjabis were studied for basal paraoxonase activity (P), in presence of 1 M NaCl (salt-activated) using paraoxon as substrate and arylesterase activity (A) using phenylacetate as substrate.
  
  
  RESULTS
  The mean (+ SD) activity of these in population was 70.43 (+/-30.41), 103.11 (+/-42.87) nmol/min/ml plasma and 36.81 (+/- 9.87) micromol/min/ml plasma, respectively, with no significant difference in sexes. Based on the ratio of SAP activity to A activity, 3 distinct phenotypes could be determined with gene frequencies of PON*A and PON*B being 0.845 and 0.155, respectively. Between P and A, and SAP and A in both A and AB phenotypes, significant correlation was observed (A = r 0.34 and 0.62, p < 0.01; B = r 0.31 and 0.81, p > 0.01), suggesting that both enzymes belong to the same group.
  
  
  CONCLUSIONS
  Though northwestern Indian Punjabis have trimodal paraoxonase activity, the majority is either low homozygous (AA) or heterozygous (AB) type with enzyme activity lower than Europids.
authors.affiliation: Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: S
authors.initials: S
authors.lastname: Singh
authors.forename: M
authors.initials: M
authors.lastname: Verma
authors.forename: C K
authors.initials: CK
authors.lastname: Nain
authors.forename: L
authors.initials: L
authors.lastname: Co
authors.forename: R C
authors.initials: RC
authors.lastname: Goel
authors.forename: B K
authors.initials: BK
authors.lastname: Sharma
mesh_terms: D000328:Adult; D000483:Alleles; D043303:Aryldialkylphosphatase; D004789:Enzyme Activation / Q000187:drug effects; D004950:Esterases / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011110:Polymorphism, Genetic; D012727:Sex Characteristics; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D012965:Sodium Chloride; D004950:Esterases; D043303:Aryldialkylphosphatase