Chapter 17, Problem 14RQ

If a test were available that could tell you whether you were likely to develop a disorder such as schizophrenia later in life, would you take the test? Why or why not? Rachel asked to see a genetic counselor because she was concerned about developing schizophrenia. Her mother and maternal grandmother both had schizophrenia and were institutionalized for most of their adult lives. Rachels three maternal aunts are all in their 60s and have not shown any signs of this disease. Rachels father is alive and healthy, and his family history does not suggest any behavioral or genetic conditions. The genetic counselor discussed the multifactorial nature of schizophrenia and explained that many candidate genes have been identified that may be mutated in individuals with the condition. However, a genetic test is not available for presymptomatic testing. The counselor explained that based on Rachels family history and her relatedness to individuals who have schizophrenia, her risk of developing it is approximately 13%. If an altered gene is in the family and her mother carries the gene, Rachel has a 50% chance of inheriting it.

Identify a possible advantage and a possible disadvantage of a genetic test that would identify genes in individuals that increase their probability of having Alzheimer’s disease later in life.

Overall, the normal ratio is about 0.2 0.4 0.6 0.8

Which of the following statements can be falsified? a. All of the fish in Lake Michigan are brown. b. French cheese is the tastiest. c. Homeopathic remedies work only if you believe in them.

________ Although the incidence of neural tube defects in the United States declined post-folic acid fortification, some women are still at risk. Which of the following options represents a risk group for inadequate folate status and a neural tube defect affected pregnancy? a. Non-Hispanic Black women b. Non-Hispanic White women c. Asian Americans d. Hispanic Americans

Name three genes whose mutations lead to an altered behavioral phenotype. Briefly describe the normal function of the mutated gene as well as the altered phenotype.

The following family has a history of inherited breast cancer. Betty (grandmother) does not carry the gene. Don, her husband, does. Dons mother and sister had breast cancer. One of Betty and Dons daughters (Sarah) has breast cancer; the other (Karen) does not. Sarahs daughters are in their 30s. Dawn, 33, has breast cancer; Debbie, 31, does not. Debbie is wondering if she will get the disease because she looks like her mother. Dawn is wondering if her 2-year-old daughter (Nicole) will get the disease. a. Draw a pedigree indicating affected individuals and identify all individuals. b. What is the most likely mode of inheritance of this trait? c. What are Dons genotype and phenotype? d. What is the genotype of the unaffected women (Betty and Karen)? e. A genetic marker has been found that maps very close to the gene. Given the following marker data for chromosomes 4 and 17, which chromosome does this gene map to? f. Using the same genetic marker, Debbie and Nicole were tested. The results are shown in the following figure. Based on their genotypes, is either of them at increased risk for breast cancer?