genetic disease Flashcards
what is penetrance?
proportion of those that carry the gene will express the trait.
what is expressivity?
how the gene is expressed in an individual with same mutation
what is a disorder caused by single genes with large effects?
cystic fibrosis and sickle cell anaemia.
what type of disorder will be caused by chromosomal disorders?
Downs syndrome.
What are complex multigenic disorders?
- gene variants.More than one gene or mutation within a gene associated with conditions.
- each variant has low penetrance and small effect.
what are single nucleotide polymorphisms (SNPs)?
change in one nucleotide pair
What are contiguous repeats?
dinucleotides
tri (3)
tetra (4)
what is a silent mutation?
no change in amino acid sequence
what is missense?
change in amino acid sequence
what is a nonsense mutation?
premature stop codon
what is an amino acid sequence that changes but retains biochemical properties called?
conservative
what is the amino acid sequences that is changed but changes biochemical properties?
non conservative.
what is frameshift mutation caused by?
insertion and deletion unless it is insertion or deletion of 3 nucleotides.
when is a disorder not X-linked?
when passed on from male to male
when is a disorder not mitochondrial?
when passed on from male.