Test Bank Thompson & Thompson Genetics in Medicine 8th Edition Authors Robert L. Nussbaum, Roderick R. McInnes, Huntington F Willard.

Chapter 8: Complex Inheritance of Common Multifactorial Disorders 1. Which of the following is characteristic of multifactorial inheritance? A) Disorders caused by a single gene mutation B) Disorders influenced by both genetic and environmental factors C) Disorders only transmitted through mitochondrial DNA D) Traits passed solely through dominant alleles Answer: B Rationale: Multifactorial disorders arise from the interaction of multiple genes and environmental factors, such as lifestyle or diet. 2. A nurse is assessing a patient with a family history of type 2 diabetes. Which concept applies to this disorder? A) Autosomal dominant inheritance B) Multifactorial inheritance C) X-linked inheritance D) Mitochondrial inheritance Answer: B Rationale: Type 2 diabetes is a common example of a disorder with multifactorial inheritance. 3. Which term describes the phenomenon where multiple genetic and environmental factors contribute to a disease threshold? A) Genetic drift B) Polygenic inheritance C) Threshold model D) Gene-environment correlation Answer: C Rationale: The threshold model explains that for a multifactorial disorder to manifest, the cumulative effect of genetic and environmental factors must surpass a certain threshold. 4. Which of the following is an example of a multifactorial disorder? A) Huntington’s disease B) Cystic fibrosis C) Coronary artery disease D) Hemophilia A Answer: C Rationale: Coronary artery disease is influenced by multiple genetic and environmental factors, making it a multifactorial disorder. 5. A nurse is counseling a patient with a family history of hypertension. What should the nurse emphasize? A) Lifestyle changes can modify the risk of developing the condition. B) The disorder follows a Mendelian inheritance pattern. C) Environmental factors have no influence on the disease. D) The condition will inevitably develop if both parents have hypertension. Answer: A Rationale: Hypertension is a multifactorial disorder, meaning environmental factors like diet and exercise can modify the risk. 6. Which type of study is most useful in assessing the genetic contribution to multifactorial disorders? A) Case-control study B) Genome-wide association study (GWAS) C) Randomized controlled trial D) Cohort study Answer: B Rationale: GWAS identify genetic variations across the genome that are associated with complex traits and multifactorial disorders. 7. Which multifactorial disorder has been associated with the APOE gene? A) Type 1 diabetes B) Alzheimer’s disease C) Cystic fibrosis D) Fragile X syndrome Answer: B Rationale: Variants in the APOE gene, particularly APOE ε4, are associated with an increased risk of Alzheimer’s disease. 8. A nurse advises a pregnant woman about folic acid intake. Which multifactorial condition is folic acid known to help prevent? A) Neural tube defects B) Down syndrome C) Turner syndrome D) Duchenne muscular dystrophy Answer: A Rationale: Adequate folic acid intake during pregnancy can reduce the risk of neural tube defects in the fetus. 9. What is the term for genetic susceptibility to a disease that only manifests in the presence of environmental triggers? A) Epigenetics B) Heritability C) Genetic predisposition D) Genetic drift Answer: C Rationale: Genetic predisposition refers to an increased likelihood of developing a disease due to specific genetic factors, which may require environmental triggers to manifest. 10.A patient with familial hypercholesterolemia is being counseled. Which pattern of inheritance does this disorder exhibit? A) Autosomal recessive B) X-linked recessive C) Autosomal dominant D) Multifactorial Answer: C Rationale: Familial hypercholesterolemia follows an autosomal dominant inheritance pattern but also has environmental influences on disease severity. 11.Which gene-environment interaction contributes to the development of type 2 diabetes? A) Sedentary lifestyle and genetic variants in the TCF7L2 gene B) Low folate levels and mutations in the CFTR gene C) Exposure to UV light and mutations in the BRCA1 gene D) Smoking and deletions on chromosome 21 Answer: A Rationale: Variants in the TCF7L2 gene combined with a sedentary lifestyle increase the risk of type 2 diabetes. 12.Which concept explains why identical twins might not always develop the same multifactorial disorder? A) Genetic heterogeneity B) Incomplete penetrance C) Environmental variation D) Pleiotropy Answer: C Rationale: Environmental factors can differ between identical twins, leading to differences in the expression of multifactorial disorders. 13.Which characteristic is commonly seen in multifactorial diseases? A) Early onset with severe symptoms B) Predictable inheritance patterns C) Clustering within families D) A single gene responsible for the condition Answer: C Rationale: Multifactorial diseases tend to cluster in families due to shared genetic and environmental factors. 14.Which of the following traits is likely to follow a multifactorial pattern of inheritance? A) Eye color B) Cystic fibrosis C) Sickle cell anemia D) Blood type Answer: A Rationale: Traits like eye color are influenced by multiple genes and environmental factors, making them multifactorial. 15.A patient asks about heritable risk for schizophrenia. What should the nurse explain? A) Schizophrenia is strictly genetic and environmental factors do not influence it. B) Family history increases the risk, but environmental factors also play a significant role. C) Schizophrenia follows a simple Mendelian pattern of inheritance. D) The disorder can only be inherited through the paternal lineage. Answer: B Rationale: Schizophrenia is a multifactorial disorder, with both genetic predisposition and environmental factors contributing to its development