title: Polymorphisms of CDKN1A gene and risk of retinoblastoma.
abstract: Retinoblastoma (RB) is a malignant neoplasia that occurs mostly in children under 5 years. Recently, CDKN1A gene has been shown to be up-regulated in a context of loss of function of pRb. This gene encodes the p21 protein, which is the bona fide effector of p53. We hypothesized whether two putatively functional single nucleotide polymorphisms (SNPs) of CDKN1A (rs1801270 C>A and rs1059234 C>T) may influence the risk and/or survival of RB patients. We genotyped both SNPs in 141 RB patients and 120 unrelated healthy individuals. Statistical analyses consisted of chi-square (χ(2)), odds ratio (OR) and survival curves by Kaplan-Meier method. We found that patients who carry the genotype CA for rs1801270 and CT for rs1059234 were associated to an increased risk of RB [OR = 2.5, 95% confidence interval (CI) = 1.38-4.53], whereas patients with CC for both polymorphisms were associated to a lower risk of developing RB (OR = 0.43, 95% CI = 0.25-0.74). On the other hand, Kaplan-Meier curves did not show statistically significant differences in survival among the studied polymorphisms. We conclude that the minor alleles of rs1801270 and rs1059234 polymorphisms may act as risk factors for the development of RB in our sample.
  
  
  CONCLUSIONS
  The minor alleles of polymorphisms rs1801270 C>A and rs1059234 C>T in CDKN1A (p21) gene may act as risk factors for the development of RB; however, they do not seem to influence overall survival.
authors.affiliation: Genetics and Molecular Biology Department, Universidade Federal do Estado do Rio de Janeiro (UNIRIO), 20211-040 Rio de Janeiro, Brazil.
authors.forename: Ivna Néria Silva Ribamar
authors.initials: IN
authors.lastname: Carvalho
authors.forename: Adriana Helena de Oliveira
authors.initials: AH
authors.lastname: Reis
authors.forename: Pedro H
authors.initials: PH
authors.lastname: Cabello
authors.forename: Fernando Regla
authors.initials: FR
authors.lastname: Vargas
mesh_terms: D000483:Alleles; D016022:Case-Control Studies; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012175:Retinoblastoma / Q000235:genetics*; D012307:Risk Factors; D015996:Survival Rate
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21