Figure 2 is a flow diagram of included studies about prevalence and penetrance. The studies are of asymptomatic women. Studies of asymptomatic women and prevalence are divided into 3 categories: unselected population, with 4 studies; high-risk population, including early-onset cancer, selected cohorts, and high-risk families, with 26 studies; and Ashkenazi Jewish population, with 9 studies. Studies of asymptomatic women and penetrance are divided into 4 categories: BRCA-positive women, meaning they have detected deleterious BRCA1 or BRCA2 mutations, with 30 studies and 3 meta-analyses; variant of uncertain significance, meaning an abnormality of the BRCA1 or BRCA2 gene, but it is not known whether it is associated with an increased risk for cancer, no studies; uninformative negative, meaning no known deleterious genetic mutations in relatives, and none detected in the patient, with 3 studies; and true negative, meaning known confirmed deleterious genetic mutation in relatives and none detected in the patient, with 10 studies.

Figure 2Included Studies of Prevalence and Penetrance

From: 3, RESULTS

Cover of Risk Assessment, Genetic Counseling, and Genetic Testing for BRCA-Related Cancer
Risk Assessment, Genetic Counseling, and Genetic Testing for BRCA-Related Cancer: Systematic Review to Update the U.S. Preventive Services Task Force Recommendation [Internet].
Evidence Syntheses, No. 101.
Nelson HD, Fu R, Goddard K, et al.

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