Genetics | From Genes To Genomes Hartwell 6th Edition Pdf

Emma and Jack decide to undergo genetic testing to determine their risk of developing these conditions. They meet with a genetic counselor to discuss their family history and test results.

Meet Emma and her first cousin, Jack. Emma's mom and Jack's mom are sisters, making them first cousins. Both Emma and Jack are healthy, but their family has a history of certain genetic disorders. genetics from genes to genomes hartwell 6th edition pdf

Emma's grandmother, who is Jack's great-aunt, suffers from , a neurodegenerative disorder caused by an autosomal dominant mutation in the HTT gene (Chapter 4, p. 134, Hartwell et al., 6th edition). This means that a single copy of the mutated gene is enough to cause the disease. Emma's grandmother inherited the mutated gene from her mother, and there's a 50% chance that Emma inherited it too. Emma and Jack decide to undergo genetic testing

The HTT gene mutation in Emma's family is an example of a , caused by a single gene mutation (Chapter 4, Hartwell et al., 6th edition). In contrast, breast cancer is a complex disease , influenced by multiple genetic and environmental factors (Chapter 16, Hartwell et al., 6th edition). Emma's mom and Jack's mom are sisters, making

References: Hartwell, L. H., Hood, L., Plunckett, W., Scott, M. P., Goldfarb, M. P., & Zipursky, S. L. (2019). Genetics: From Genes to Genomes (6th ed.). McGraw-Hill Education.

The counselor explains that Emma has a 50% chance of inheriting the HTT mutation, which would put her at risk for Huntington's disease. Emma decides to take the test and learns that she did not inherit the mutation. She feels relieved, but also grateful for the opportunity to make informed decisions about her life and family planning.

Jack's mom has , which runs in their family. Testing revealed that Jack's mom is a carrier of a BRCA1 mutation (Chapter 16, p. 535, Hartwell et al., 6th edition). This mutation increases the risk of breast and ovarian cancer. As a carrier, there's a 50% chance that Jack inherited the mutated gene.