Revista Brasileira de Ginecologia e Obstetrícia (Jan 2011)
Análise do polimorfismo no códon 72 do gene TP53 em mulheres inférteis com e sem endometriose Analysis of codon 72 polymorphism of the TP53 gene in infertile women with and without endometriosis
Abstract
OBJETIVO: avaliar a frequência do polimorfismo no códon 72 do gene TP53 em mulheres inférteis com endometriose, mulheres com infertilidade idiopática, Grupo Controle e sua associação com a doença. MÉTODOS: estudo caso-controle que incluiu 198 mulheres inférteis com endometriose, 70 mulheres com infertilidade idiopática e 169 mulheres férteis sem endometriose como controles. O polimorfismo no códon 72 do gene TP53 (rs1042522, Arg/C:Pro/G), que promove uma troca de C/G na sequência codante, foi identificado pela reação em cadeia da polimerase (PCR) em tempo real, por meio da utilização de sistema TaqMan de primers, flanqueando a região em questão e sondas marcadas com fluoróforos diferentes, uma para o alelo C, outra para o alelo G. Na observação de dois fluoróforos, o paciente foi considerado heterozigoto para o polimorfismo. Na presença de apenas um fluoróforo, o paciente foi considerado homozigoto CC ou GG. O teste do χ2 foi utilizado para comparar as frequências dos genótipos e alelos entre os grupos. Todos os valores de p foram bicaudais, e o nível de significância considerado foi 0,05 (α PURPOSE: to evaluate the frequency of TP53 codon 72 polymorphism in infertile women with endometriosis, women with idiopathic infertility, controls and its relation to the disease. METHODS: a case-control study that included 198 infertile women with endometriosis, 70 women with idiopathic infertility and 169 fertile women without endometriosis as control. Detection of TP53 codon 72 gene polymorphism (rs1042522, Arg/C:Pro/G), that promotes a C/G exchange in the coding region of the gene, was performed by real time Polymerase Chain Reaction (PCR), using the TaqMan system of primers, that flank the implicated region and probes labeled with different fluorescent dyes, one for allele C and other for allele G. When two dyes were observed, the patient was considered to be heterozygous CG. In the presence of only one dye, the individual was considered to be homozygous CC or GG. The χ2 test was used to compare allele and genotype frequencies between groups. All p-values were two-tailed and a p-value <0.05 was considered to be statistically significant. RESULTS: we found no statistically significant difference in the distribution of TP53 codon 72 polymorphism genotypes CC, CG or GG (p=0.7) and alleles C or G (p=0.4) between infertile patients with endometriosis and controls (p=0.4), regardless of the stage of the disease. In relation to infertility, no statistically significant difference in the genotype or allele distribution (p=1.0 and p=0.9, respectively) was observed between idiopathic infertile women and controls. Considering the dominant inheritance model, again, no statistically significant difference was found even in the endometriosis (p=0.5) or the idiopathic infertility group (p=0.9) when compared to controls. Regarding the recessive inheritance model no statistically significant difference was found, with p=0.6 and p=1.0, respectively, for the endometriosis and idiopathic infertility groups. CONCLUSION: the results suggest that the TP53 codon 72 polymorphism does not confer genetic susceptibility to endometriosis and/or infertility in the Brazilian population, not even the severe form of the disease.
Keywords
