MICROBIO 160 Lecture Notes - Lecture 14: Twin, Brca1, Twin Study

• School: UMASS-Amherst
• Department: Microbiology
• Course: MICROBIO 160
• Professor: Wilmore Welby

Document Summary

The easiest way to test risk is through twin studies. Risk between identical and non-identical twins has allowed a good estimate of how much of all breast cancer risk is inherited. Data from twin and cancer registries in sweden, denmark, and finland (547 pairs of identical twins and 1075 pairs of non-identical twins) reported that about 25-27% of the total risk of breast cancer was due to inherited factors. Women with family history of breast cancer make up only 5 to 7 percent of all women with breast cancer. Sporadic breast cancer occurs at a specific (older) age and no other family member has it. Effect of birth year on breast cancer risk from brca mutations. Women born after 1940 carrying mutations in brca1 or 2 genes have higher breast. This difference indicates that non-genetic factors influence breast cancer risks even in cancer rates than women born before 1940 who carry the same mutations. individuals who inherit high risk mutations.