Thomas discovered a devastating piece of family historywhen he learned that his brother had been diagnosed withHuntington disease (HD) at age 49. This dominantly inheritedautosomal condition usually begins around age 45 with progressivedementia, muscular rigidity, and seizures and ultimatelyleads to death when affected individuals are in their early 60s. Therecurrently is no effective treatment or cure for this genetic disorder.Thomas, now 38, wonders what the chances are that he also hasinherited the mutant allele for HD, leading him to discuss with hiswife whether they should seek genetic counseling and whether heshould undergo genetic testing. They have two teenage children, aboy and a girl. Question : If you were in Thomas’s position, would you want to be testedand possibly learn that you were almost certain to develop thedisorder sometime in the next 5–10 years?

Thomas discovered a devastating piece of family historywhen he learned that his brother had been diagnosed withHuntington disease (HD) at age 49. This dominantly inheritedautosomal condition usually begins around age 45 with progressivedementia, muscular rigidity, and seizures and ultimatelyleads to death when affected individuals are in their early 60s. Therecurrently is no effective treatment or cure for this genetic disorder.Thomas, now 38, wonders what the chances are that he also hasinherited the mutant allele for HD, leading him to discuss with hiswife whether they should seek genetic counseling and whether heshould undergo genetic testing. They have two teenage children, aboy and a girl. Question : If you were in Thomas’s position, would you want to be testedand possibly learn that you were almost certain to develop thedisorder sometime in the next 5–10 years?

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter11: Genome Alterations: Mutation And Epigenetics

Section: Chapter Questions

Problem 16QP: Familial retinoblastoma, a rare autosomal dominant defect, arose in a large family that had no prior...

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A 30 - year - old woman was undergoing therapy for b-thalassemia,a recessive trait caused by absence of or reduced synthesis ofthe hemoglobin b chain, a subunit of the oxygen-carrying moleculein red blood cells. In this condition, red blood cells are rapidlydestroyed, freeing a large amount of iron, which is deposited in tissuesand organs. The blood transfusions the patient had received every twoor three weeks since the age of 7 to stave off anemia were furtheraggravating iron buildup. Her major organs were showing damage, andshe was in danger of death from cardiac disease. Her physician suggestedthat she consider undergoing a hematopoietic (bone marrow)stem cell transplant (HSCT). Since these stem cells give rise to redblood cells, such a transplant could potentially restore her health. Whilethis might seem like an easy decision, it is not. Advanced cases havea high risk (almost 30 percent) for transplantation-related death. At thispoint, the woman is faced with a difficult and…
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