Recent years, the genetic test was used for cancer screening. BRCA ½ are two gen

Question

Recent years, the genetic test was used for cancer screening. BRCA ½ are two genes related to breast cancer. When the BRCA ½ mutation testing is positive, the women will be in higher risk of developing breast cancer over the lifetime. According to European Molecular Genetics Quality Network*, that 97.1% of women with BRCA ½ mutation and 2.7% of women without BRCA ½ mutation are tested with positive results in genetic laboratories test. From the literature, the prevalence of BRCA ½ mutation among women in the general population is 0.2%

What is the probability that a woman randomly selected from the population doesn't have BRCA ½ mutation given that her BRCA ½ mutation test is negative

Explanation / Answer

P(test negative) =P(have BRCA and tested negative+does not have BRCA and tested negative)

=0.002*(1-0.971)+(1-0.002)*(1-0.027)=0.9711

hence probability that a woman randomly selected from the population doesn't have BRCA ½ mutation given that her BRCA ½ mutation test is negative

=P(does not have BRCA and tested negative)/P(tested negative)

=(1-0.002)*(1-0.027)/0.9711 =0.99994

Related Questions

Navigate

• Browse (All)
• Browse R
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.