Genetics Flashcards
What are the genetics of Marfan syndrome?
Caused by variation in the FBN1 (fibrillin-1) gene
- Autosomal dominant
Pleiotropy: where a genetic condition affects multiple tissues or organs
What are genetics of sickle cell anaemia?
Caused by a change in one nucleotide, apoint mutationin theHBB gene
- Example of pleiotropy
Albinism is a result of mutation of which gene?
TYR gene
- Example of pleiotropy
- Autosomal recessive
Genetics of HHT?
Hereditary haemorrhagic telangiectasia - autosomal dominant
Mutations in which gene is implicated in retinoblastoma, as well as other cancers
RB1 gene
- Bilateral disease occurs earlier than unilateral
Also osteosarcoma, melanoma, soft tissue cancers
How many CAG repeats for clinically apparent Huntington’s disease?
At least 40
- Gain-of-function
Features of Friedrich’s ataxia?
GAA trinucleotide repeat, AR
- Ataxia
- Scoliosis
- Dysarthria
- HOCM
- Diabetes
Genes associated with late-onset Alzheimer’s?
APOE4
Genetics early onset Alzheimer’s?
APP (amyloid precursor protein) and presenilin (PSEN)
Frameshift mutation
Change the triplet reading frame - usually big effects/always leads to loss of function
Missense mutation
Point mutation > change in AA; may lead to loss of function, gain-of-function or altered function
Nonsense mutation
Point mutation > changes to a stop codon > always lead to loss of function
Which nucleotide is the most redundant?
3rd nucleotide
Which nucleotide is the most redundant?
3rd nucleotide
Transactive response DNA binding protein of 43 kDa (TDP-43) is associated with which set of conditions?
Neurodegenerative conditions
- Amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), Alzheimer’s disease (AD), and limbic predominant age-related TDP-43 encephalopathy (LATE)
