Pedigree Flashcards
pedigreee
shows how a trait is inherited
carrier
individuals who are hetero and do not show symptoms of the disease
first person with the genetic disorter in a pedigree
proband
the person who brings the family to the geneticist
consultand
kindred
all family in tree
mendelian disorders are known as
single gene disorders
what are the 2 factors that pedigrees depend on
- if phenotype is dominant or recessive
2. choromsomal location of the gene locus
if a person has a AD phenotype what is theri chance of transmitting the allele?
50% chance , this accounts for more than half of all mendelian disorders
AD DISORDER:
what is the most common pattern of inheritance for AD
verticle , in every generation .
Each child has a 50% chance of inheriting it if they have an affected parent.
If a child has it, they MUST have at least one AFFECTED parent.
clinical variability
compound heterozygytes
both alleles are mutant at the same locus
AR DISORDER
Affect men and women equally.
likely occur when maried bn family (consanguinity)
Child can get it without having an affected parent
Each child of a carrier parent has a 25% chance of being affected
Horizontal Pattern
Less clinical variablity
blue eyes
red hair
cystic fibrosis
sickcle cell
all these remind you of…
AR traits
X LINKED DOMINANT
more affected females than males
lack of male to male transmission (fathers pass y to sons ). But all daughters will have the disease
verticle transmission
examples of x linked dom traits
rickets
Rett
incontienta pigmenti
HOW TO DISTINGUISH AD FROM XLD
FIND AN AFFECTED MALE:
ONLY GIVE TO DAUGHTERS (NOT SONS = X LINKED DOM