title: Genotype by diabetes interaction effects on the detection of linkage of glomerular filtration rate to a region on chromosome 2q in Mexican Americans.
abstract: OBJECTIVE
  Glomerular filtration rate (GFR) is used to assess the progression of renal disease. We performed linkage analysis to localize genes that influence GFR using estimated GFR data from the San Antonio Family Diabetes/Gallbladder Study. We also examined the effect of genotype by diabetes interaction (G x DM) on the detection of linkage to address whether genetic effects on GFR differ in diabetic and nondiabetic subjects.
  
  
  METHODS
  GFR (N = 453) was estimated using the recently recalculated Cockcroft-Gault (GFR-CGc) and the simplified Modification of Diet in Renal Disease (GFR-4VMDRD) formulae. Both estimates of GFR exhibited significant heritabilities, but only GFR-CGc showed significant G x DM interaction. We therefore performed multipoint linkage analyses on both GFR measures using models that did not include G x DM interaction effects (Model 1) and that included G x DM interaction effects (Model 2, in the case of GFR-CGc).
  
  
  RESULTS
  The strongest evidence for linkage (Model 1) of both GFR-CGc (logarithm of odds [LOD] 2.9) and GFR-4VMDRD (LOD 2.6) occurred between markers D9S922 and D9S1120 on chromosome 9q. However, using Model 2, the strongest evidence for linkage of GFR-CGc on chromosome 2q was found near marker D2S427 (corrected LOD score [LOD(C)] 3.3) compared with the LOD score of 2.7 based on Model 1. Potential linkages (LOD or LOD(C) >or=1.2) were found only for GFR-CGc on chromosomes 3p, 3q, 4p, 8q, 11q, and 14q.
  
  
  CONCLUSIONS
  We found a major locus on chromosome 2q that differentially influences GFR in diabetic and nondiabetic environments in the Mexican-American population.
authors: Southwest Foundation for Biomedical Research, Department of Genetics, P.O. Box 760549, San Antonio, TX 78254, USA. spuppala@sfbrgenetics.org
authors: Sobha
authors: S
authors: Puppala
authors: Rector
authors: R
authors: Arya
authors: Farook
authors: F
authors: Thameem
authors: Nedal H
authors: NH
authors: Arar
authors: Kusum
authors: K
authors: Bhandari
authors: Donna M
authors: DM
authors: Lehman
authors: Jennifer
authors: J
authors: Schneider
authors: Sharon
authors: S
authors: Fowler
authors: Vidya S
authors: VS
authors: Farook
authors: Vincent P
authors: VP
authors: Diego
authors: Laura
authors: L
authors: Almasy
authors: John
authors: J
authors: Blangero
authors: Michael P
authors: MP
authors: Stern
authors: Ravindranath
authors: R
authors: Duggirala
authors: Hanna E
authors: HE
authors: Abboud
mesh_terms: D000328:Adult; D000368:Aged; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2; D003920:Diabetes Mellitus / Q000235:genetics*; D003928:Diabetic Nephropathies / Q000235:genetics; D005260:Female; D005838:Genotype; D005919:Glomerular Filtration Rate / Q000235:genetics*; D006630:Hispanic or Latino / Q000235:genetics*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000235:genetics; D008297:Male; D008875:Middle Aged; D012016:Reference Values