Mutations Flashcards
1
Q
A
2
Q
Mutation
A
- any change in the DNA sequence of an organism
- source of the altered versions of genes that provide the raw material for evolution
(only germline mutations are transmitted over generations) - most cause no affect, are neutral
3
Q
Autosomal recessive inheritance
A
- associated with Loss of Function mutations
- remember that diploids have two alleles(this means that one allele can still carry the LOF mutation, while the other allele can produce a functional protein product)
- of both alleles are hit with a LOF mutation, this creates a autosomal recessive disease
4
Q
Autosomal dominant inheritance
A
- associated with Gain of Function mutations
- only ONE allele has to be hit with a GOF mutation in order to develop disease (typically for humans two GOF alleles are embryonically lethal)
5
Q
Autosomal dominant pattern: missense/nonsynonymous/replacement
A
- A missense/nonsynonymous/replacement mutation leads to a different animo acid in the protein product.
-If the different amino acid causes the protein to function abnormally (e.g. an enzyme with an increased rate), this leads to an autosomal dominant disease.
6
Q
Autosomal dominant inheritance pattern: what causes big increase in quantity of protein produced
A
- A mutation in a regulatory switch can lead to too much protein produced, protein made in the wrong cell or tissue type, and/or protein produced in the wrong time during ontogeny
- if one GOF allele mutation in regulatory switch, leads to auto. dom. disease
7
Q
Trans-sequence
A
- sequence change in protein coding DNA sequences
8
Q
Cis regulatory sequence
A
- sequence change in non-coding regulatory switch DNA sequences
9
Q
Silent mutation
A
- exon mutation
- base subsitution
- alters no amino acids
- has no effect on protein function
10
Q
Missense
A
- exon mutation
- base substitution
- alters a nucleotide, which leads to a change of one amino acid
- can be neutral or inhibitory (so a LOF or a GOF)
11
Q
Nonsense
A
- exon mutation
- base subsitution
- Uracil replaces Thymine for RNA
-creates a stop codon - creates short protein
- alters many amino acids, is an ihibitory LOF for proteins
12
Q
Frameshift
A
- changes multiple amino acids
- creates a addition/deletion mutation in DNA
- exon mutation
- alters many amino acids
- inhibitory LOF on proteins
(exception: insertions and deletions of three will not create a framshift, will be a GOF allele)
13
Q
Sickle Cell Anemia
A
- missense mutation that creates LOF
- leads to different protein with sickle-like blood cells
14
Q
Cystic Fibrosis
A
- missing amino acid or defect alters conformation of chloride channels in certain epithelial cell plasma membranes
- water enters cells, drying out secretions
- frequent lung infection, pancreatic insuffciency
15
Q
Duchenne muscular dystrophy
A
- deletion eliminates dystrophin, which normally binds to inner face of muscle cell plasma membranes, maintaining cellular integrity
- cells and muscles weaken
- gradual loss of muscle function
16
Q
Familial hypercholestolemia
A
- deficient LDL receptors cause cholesterol to accumulate in the blood
- high blood cholesterol
17
Q
Hemophilia A
A
- absent or deficient clotting factor causes hard-to-control bleeding
- slow or absent blood clotting
18
Q
Huntington disease
A
- extra bases in the gene add amino acids to the protein product, which impairs certain transcription factors and proteasomes
- uncontrollable movements
19
Q
Marfan Syndrome
A
- deficient connective tissue protein in lens and aorta
- long limbs, sunken chest, lens dislocation
20
Q
Neurofibromatosis
A
- defect in protein that normally suppresses activity of a gene that causes cell division
- benign tumors of nervous tissue beneath skin
