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Why do you think it has been so difficult to identify genes underlying schizophrenia?
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. Rachel’s three maternal aunts are all in their 60s and have not shown any signs of this disease. Rachel’s 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 Rachel’s 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.
To describe: The difficulties to identify genes underlying schizophrenia.
Introduction: Schizophrenia is characterized by thought disorders, delusions, and anti-social behavior. This is much common in children and at least lasts for 6 months. Schizophrenia is found within a region of DNA located on chromosome 6. The genes underlying the disease are still unknown.
Explanation of Solution
Schizophrenia is a behavioral disorder that causes widespread human suffering. Several genetic studies have shown that hundreds of genes are linked to schizophrenia. Each gene contributes a small part to the risk of developing the disease.
Therefore, a mutation in a gene does not confirm the presence of schizophrenia. Similarly, if someone has schizophrenia with a mutation in a gene also does not mean that this mutation is responsible for the behavior of the respective person.
Hence, it is difficult to find genetic determinants underlying schizophrenia.
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Chapter 18 Solutions
Human Heredity: Principles and Issues (MindTap Course List)
- A region on chromosome 6 has been linked to schizophrenia, but researchers have not found a specific gene associated with this disease. What steps would be necessary to locate the gene?arrow_forwardIf 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.arrow_forwardWhat is the "common disease, common variant hypothesis for the genetic basis of mental health disorders? How is this different than "rare variants"?arrow_forward
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Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning