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Genetic and Congenital Disorders
Genetic and Congenital Disorders ( 4 Questions)
A nurse is caring for a client who has a family history of Huntington disease. The nurse understands that this condition is caused by what type of mutation in a single gene?
Loss-of-function mutation is a type of mutation that reduces or eliminates the normal function of a gene or protein. This can result in diseases such as cystic fibrosis, phenylketonuria, or sickle cell anemia.
No explanation
Haploinsufficiency mutation is a type of mutation that reduces the amount or activity of a gene or protein to less than 50% of the normal level. This can result in diseases such as Marfan syndrome, familial hypercholesterolemia, or Waardenburg syndrome.
Dominant negative mutation is a type of mutation that produces an abnormal protein that interferes with the normal protein and prevents it from functioning properly. This can result in diseases such as osteogenesis imperfecta, Ehlers-Danlos syndrome, or Holt-Oram syndrome.
Choice B reason Huntington disease is caused by a mutation in the HTT gene that encodes for the huntingtin protein. The mutation involves an expansion of the CAG trinucleotide repeat in the gene, which results in an abnormal protein with an elongated polyglutamine tract. This protein gains a new toxic function that interferes with the normal function of other proteins and causes neuronal degeneration in the brain.
Choice A reason:
Loss-of-function mutation is a type of mutation that reduces or eliminates the normal function of a gene or protein. This can result in diseases such as cystic fibrosis, phenylketonuria, or sickle cell anemia.
Choice C reason:
Haploinsufficiency mutation is a type of mutation that reduces the amount or activity of a gene or protein to less than 50% of the normal level. This can result in diseases such as Marfan syndrome, familial hypercholesterolemia, or Waardenburg syndrome.
Choice D reason:
Dominant negative mutation is a type of mutation that produces an abnormal protein that interferes with the normal protein and prevents it from functioning properly. This can result in diseases such as osteogenesis imperfecta, Ehlers-Danlos syndrome, or Holt-Oram syndrome.