Lecture #61

  1. Pedigree
    • male=square; female=circle
    • carrier = colored in dot in male or femal
    • affected =filled in with color
    • straight line= marriage or union 
    • arrow pointed=proband first person IDed with disease condition
    • generation designated by roman numerals
    • regular numer show how many in generation
  2. autosomal recessive inheritance
    • affects both sex
    • two carrier parent made a carrier offspring

    the ofspring of affected could be carrier
  3. examples of autosomal recessive inheritance
    • cyctis fibrosis 
    • sickel cell anemia
  4. autosomal dominant
    • both sexes equally affected
    • no generational skipping
    • male and female equally pass on
  5. exaples of autosomal dominant inheritance
    • marfan syndrome
    • achodroplasia
  6. recurrent risk
    understanding percentage of offspring being dominant, carriers, and recessive
  7. what is unique about the recurrent risk of achondraplasia?
    having a homozygous dominant allel is embryonic lethal thus when calculating recurrent risk of this diseaseit would only be 66% or 2/3 since AA is lethal and will not be viable.
  8. what is significant for x-linked inheritance
    • there is no father to son transmission
    • usually male are affected
  9. recurrent risk with x linked is depending on sex
    for example if female the disease will not show
  10. why doesn't the y chromosome show disease
    y chromosome doesnt have many genes and most or jst for sex determination
  11. hemophilia A
    • deficency of factor VII of clotting cascade- easy brusining
    • nonsence/frameshift mutation
    • missence mutation
  12. types of x-linked recessive disease
    • duchenne and Beckers muscular dystrophy
    • Gloucose 6 dehydrogenase deficency 
    • color blind
    • hypohidrotic ectodermal dysplasia
  13. hypohidroticectodermal dysplasia
    • seen most in females deficency impairs development of sweat glands, hair, and teeth
    • mutation in EDA gene
    • mosaicism always for pactches of regular development because of x chromsome inactivation.
  14. mosaicism
    • x chromosme inactivation happens very early in development and the activated x chromsome is chosen randomly 
    • clones of cells that have diff expressivity of gene in respect to other
  15. X dominant inheritance disease
    very sever and lethal in all males
  16. what are some examples of x-linked dominant inheritance
    • hypophosphatemic rickets
    • incontinentia pigment type I
    • Rett syndrome
Card Set
Lecture #61
Autosomal and Sex-Linked Inheritance