Inheritance Lecture

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Inheritance Lecture
2012-08-28 21:35:27

med school
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  1. one gene affects long fingers, several organs... which disease and clinical example of and why?
    Marfan Syndrome; pleitropic because one gene affects many phenotypic traits
  2. Mom looks different from kid and grandma. (myotonic dystrophy) or long DNA seq. in Duchenne Muscular dystrophy that can be mutated anywhere along DNA are examples of?
    Phenotypic heterogeneity: same mutation with different phenotypes.
  3. Myosin/actin fibers (different genes) cause single disorder is example of?
    Locus heterogeneity
  4. Genetic heterogeneity?
    DMSP: Different Mutation Same Phenotype
  5. Long gene but 1000 mutations in same loci of gene. 
    Allelic Heterogeneity: Different mutations on the same loci of gene (Cystic fibrosis)
  6. Variable expressivity?
    Common to Allelic Heterogeneity..means severity of disease depends on mutation
  7. If two _____geneity mate, their offspring can still be normal?
    Locus heterogeneity
  8. Characteristics of autosomal dominant?
    50% chance offspring get disease; male-to-male transmission; generally AA (homozygous) is worse EXCEPT in HUNTINGTON'S
  9. Examples of gene imprinting?
    When one gene is silenced and recieved from parent.

    Prader-Willi Syndrom (paternal abnormal chromo) and Angelman Syndrome (maternal abnormal chromo)
  10. Uniparental Disomy
    One parent gives two copies of a gene to you.
  11. Mosaicism?
    When more than two populations of cells with DIFFERENT genotypes are present in body

  12. Most severe type of muscular dystrophy is caused by in-frame mutation, out-of-frame mutation, N- or C- termini mutation?
    Out-of-frame mutation (deletion) --> Duchenne's MD
  13. Definitive test for measuring dystrinopathy?
    DNA testing (gene coding)
  14. Triple repeat sequence importance?
    Worsens after every generation. 
  15. Huntington's disease repeat is ____. Worse if received from mom or dad.
    CAG; dad
  16. Fragile X repeat seq.
  17. What is genetic counseling? What is non-directive counseling?
    • GC: telling patient about the disease, risk, etc.
    • Non-Dir. C. applies 
    • to aspects of decision-
    • making which are not clearly
    • decided by scientific data
  18. Split-hand deformity?
    Example of penetrance...bc grandparents and mom/dad didnt have it, but offspring did.