RESUMO
A substantial proportion of the familial risk of breast cancer may be attributable to genetic variants each contributing a small effect. Polymorphisms in DNA repair genes are good candidates for such low penetrance breast cancer susceptibility alleles. Checkpoint kinase 2 (CHEK2) is a kinase in which the yeast counterpart regulates a cell cycle checkpoint and causes cells to arrest proliferation after DNA damage. A rare, protein truncating mutation in the CHEK2 gene has recently been shown to confer a modest risk of breast cancer. The aim of this study was to determine whether common polymorphic variants in CHEK2 are associated with an increase in breast cancer risk. We assessed two variants in CHEK2 using a case control study design (n = 1786 cases and 1828 controls). No differences in genotype frequencies were found between cases and control for either the IVS1 + 38insa or the a1013g polymorphisms (P = 0.3 and 0.2 respectively), and no genotype-specific risk was significantly different from unity. The haplotype frequency distribution in cases and controls were also similar (P = 0.3). We conclude that the CHEK2 polymorphisms IVS + 1a and a1013g do not confer an increased risk of breast cancer. It is also unlikely that other, as yet unidentified, common polymorphisms that affect risk are present in the gene in the British population.
Assuntos
Neoplasias da Mama/genética , Polimorfismo Genético , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases , Quinase do Ponto de Checagem 2 , Feminino , Humanos , Fatores de RiscoRESUMO
Most nurse managers could describe their vision of an ideal nursing unit, but seldom is a "unit vision" developed by the staff, written down and then "lived up to." Guidelines are given for such a visioning process: 1) Include everyone; 2) Seek consensus; 3) Assure congruence; 4) Find a facilitator who can elicit creativity; and 5) Keep the vision statement visible and energizing!