title: Serum calcium, urine calcium and polymorphisms of the calcium sensing receptor gene.
abstract: BACKGROUND
  Recent studies have suggested a correlation between the A986S polymorphism of the calcium sensing receptor (CASR), and serum total and ionized calcium. This study aimed to assess the prevalence of three CASR polymorphisms in a West of Scotland population and relate genotype to serum and urine calcium levels.
  
  
  METHODS
  Fasting blood and urine samples were obtained from 121 healthy male and female volunteers aged 20-60 years. Volunteers were genotyped for the A986S, Q1011E and R990G polymorphisms using allele-specific amplification and amplification-created restriction site techniques. Total calcium, ionized calcium and urine calcium excretion were measured using automated clinical chemistry analysers.
  
  
  RESULTS
  Genotype frequencies for the A986S polymorphism were: AA, 74.4%; AS, 24.8%; SS, 0.8%. There was a small but statistically significant (P < 0.01) increase in ionized calcium concentration in AS individuals compared with the wild type (1.22 versus 1.20 mmol/L). No statistical difference was detected in serum total calcium or parameters of urine calcium excretion. Genotype frequencies for the remaining polymorphisms were: RR, 82.6%; RG, 16.5%; GG, 0.8% and QQ, 93.4%; QE, 6.6%; EE, 0%. Biochemical parameters in these individuals were not statistically different from the wild type.
  
  
  CONCLUSIONS
  The increase in serum ionized calcium in the AS group was small and, therefore, unlikely to be of clinical significance.
authors.affiliation: Biochemistry Department, Wishaw General Hospital, Lanarkshire ML2 0DP, UK. claire.kelly@lanarkshire.scot.nhs.uk
authors.forename: Claire
authors.initials: C
authors.lastname: Kelly
authors.forename: Ian R
authors.initials: IR
authors.lastname: Gunn
authors.forename: Dairena
authors.initials: D
authors.lastname: Gaffney
authors.forename: Manjit S
authors.initials: MS
authors.lastname: Devgun
mesh_terms: D000328:Adult; D002118:Calcium / Q000097:blood* / Q000652:urine*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D044169:Receptors, Calcium-Sensing / Q000235:genetics*
chemical_list: D044169:Receptors, Calcium-Sensing; D002118:Calcium