Epidermal growth factor receptor polymorphism and autosomal dominant polycystic kidney disease.
BACKGROUND
The clinical variability in the rate of progression of autosomal dominant polycystic kidney disease (ADPKD) has been attributed to genetic heterogeneity, though environmental factors and modifying genes very likely play an important role as well. We examined the association between clinical outcome, defined by age at onset of end-stage renal disease (ESRD) in 46 ADPKD patients, and a polymorphism in the epidermal growth factor receptor (EGFR) gene, a candidate modifying gene. EGFR is a key element in renal tubular proliferation.


METHODS
This study comprised 46 unrelated patients with ADPKD and ESRD, and 58 healthy controls. The patients had prevalently PKD 1 mutations. The EGFR microsatellite polymorphism was genotyped according to Gebhardt et al (11).


RESULTS
The allele frequencies of the EGFR polymorphism were different in the ADPKD sample and the control population (G2=17.19; P=0.009). In particular, the frequencies of the 122 and 118bp length alleles had a different distribution (P=0.010 and P=0.047 respectively). Patients with the 122bp length polymorphism had ESRD at an earlier age,but this finding was not statistically significant.


CONCLUSIONS
These findings suggest an association between the EGFR microsatellite polymorphism and ADPKD. However, it is difficult to establish which alleles are protective and which harmful. A larger, multicenter study may help clarify these results and is also required to replicate our preliminary finding of an association between ADPKD and the EGFR polymorphism.
Magistroni
Riccardo
R
University Hospital of Modena and University of Modena and Reggio Emilia, Italy. 16433@unimo.it
Manfredini
Paolo
P
Furci
Luciana
L
Ligabue
Giulia
G
Martino
Carla
C
Leonelli
Marco
M
Scapoli
Chiara
C
Albertazzi
Alberto
A
D017668:Age of Onset; D000368:Aged; D000483:Alleles; D000704:Analysis of Variance; D016022:Case-Control Studies; D015331:Cohort Studies; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D015870:Gene Expression; D020022:Genetic Predisposition to Disease; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology / Q000235:genetics*; D016030:Kidney Transplantation / Q000379:methods; D016014:Linear Models; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D016891:Polycystic Kidney, Autosomal Dominant / Q000235:genetics* / Q000628:therapy; D011110:Polymorphism, Genetic; D011336:Probability; D012016:Reference Values; D006435:Renal Dialysis / Q000379:methods; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
D066246:ErbB Receptors