Lecture 2 Flashcards
What is the assumption made for individuals marrying into an effected individual with a non-effected child in an autosomal recessive disease?
the individual is homozygous dominant
True or False: genes can only have one allele
false, many genes have multiple alleles
What does sugar does someone with blood type A add to cell?
acetylgalactosamine
What does sugar does someone with blood type B add to cell?
galactose
What does sugar does someone with blood type AB add to cell?
acetylgalactosamine and galactose
What is haplosufficiency vs haploinsufficiency?
haplosufficiency is when one wildtype allele is dominant over a loss of function allele, and haploinsufficiency is when the wildtype is not dominant over a loss of function allele
What are recessive vs. dominant lethal alleles
recessive - kills recessive homozygotes
dominant - kills dominant homozygotes and recessive heterozygotes
What are the effects of a recessive amorphic LOF allele on a protein?
it does not produce a functional polypeptide, however this mutation is usually hidden because it is recessive
What are the effects of a hypermorphic LOF allele?
it produces a partially functioning polypeptide, however this mutation is usually hidden because it is recessive
What are the effects of a dominant negative allele?
it produces a polypeptide that can interfere with the wildtype allele, and because it is dominant this is a severe mutation
What is penetrance?
the proportion of individuals within a population that have a specific genotype and express the expected phenotype
What is expressivity?
the degree to which a phenotype is expressed in an individual
What does a combination of incomplete and variable expressivity look like?
identical known genotypes produce a broad range of phenotypes due to varying degrees of gene activation
What environmental factors effect penetrance and expressivity?
age, sex, temperature, and chemicals
What is a phenocopy?
the result of when the environment changes a genotype but produces the same phenotype
