title: KLOTHO gene polymorphism of G395A is associated with kidney stones.
abstract: OBJECTIVE
  KLOTHO, a type-1 transmembrane protein with glucurodinase activity, is expressed in tissues responsible for calcium homeostasis such as the kidney, parathyroid gland and the epithelium of the choroid plexus in the brain. Given the emerging evidence indicating a novel regulatory function for KLOTHO protein in renal calcium and phosphate homeostasis, the present study aims to investigate the association between KLOTHO genetic polymorphisms and kidney stone (KS).
  
  
  METHODS
  KLOTHO gene polymorphisms G395A in the promoter region, F252V in exon 2, and C1818T in exon 4 were investigated in 108 patients with renal calcium stone formation and 51 age-matched healthy volunteers with no history of renal stone formation, using polymerase chain reaction.
  
  
  RESULTS
  GG genotype of G395A KLOTHO polymorphism had approximately 2-fold increased KS risk compared with the homozygous genotype AA and heterozygote GA (OR 1.849, 95% CI 1.016-3.364, p = 0.044). We also found that non-A allele carriers had significantly higher KS risk associated with the KS clinical characteristics including hypercalcemia, hypophosphatemia and phosphaturia.
  
  
  CONCLUSIONS
  Our findings suggested that the G395A polymorphism of KLOTHO gene is associated with the KSs and may act as a risk factor for the development of KS disease.
authors.affiliation: Department of Genetics and Bioengineering, Yeditepe University, Istanbul, Turkey. dilek.telci@yeditepe.edu.tr
authors.forename: Dilek
authors.initials: D
authors.lastname: Telci
authors.forename: Ali Umman
authors.initials: AU
authors.lastname: Dogan
authors.forename: Emin
authors.initials: E
authors.lastname: Ozbek
authors.forename: Emre Can
authors.initials: EC
authors.lastname: Polat
authors.forename: Abdulmuttalip
authors.initials: A
authors.lastname: Simsek
authors.forename: Suleyman Sami
authors.initials: SS
authors.lastname: Cakir
authors.forename: Hakki Okan
authors.initials: HO
authors.lastname: Yeloglu
authors.forename: Fikrettin
authors.initials: F
authors.lastname: Sahin
mesh_terms: D000328:Adult; D000483:Alleles; D002118:Calcium / Q000378:metabolism; D005091:Exons; D005260:Female; D005838:Genotype; D005966:Glucuronidase / Q000235:genetics*; D006801:Humans; D007669:Kidney Calculi / Q000235:genetics*; D000090265:Klotho Proteins; D008297:Male; D008875:Middle Aged; D010710:Phosphates / Q000378:metabolism; D011110:Polymorphism, Genetic; D012306:Risk; D012307:Risk Factors
chemical_list: D010710:Phosphates; D005966:Glucuronidase; D000090265:Klotho Proteins; D002118:Calcium