DNA damage Flashcards
Fragile X syndrome
- genetic mechanismss
- clinical features
- CGG repeats of FMR1 gene on long arm of X chromosome
- anticipation: gets longer each generation b/c instability during maternal meiosis
- with a threshol length, –> CpG methylation
Complementation (mutations)
alleles of different subunits are mutated –> no disease (you will have different subcategories of disease) (so if two people mate with same diseases but of different subcategories, offspring will not have disease)
Hb lepore
- genetic mechanism
- general mechanism
- tandem repeats –> weird homologue pairing —> unequal crossover
- change in delta globin (fetal) promoter –> low expression
- thalassemia
MAP genetic mechanism?
MUTYH associated polypsis
base excision repair
autosomal recessive LOF
Xeroderma pigmentosa genetic mechanism?
nT excision repair: thymidine dimers from UV and bulky photoadducts
Lynch syndrome genetic mechanism?
mismatch repair
Fanconi anemia genetic mechanism?
DNA break reppair
biallelic mutations w at least 1/9 in subunit A
HBOC genetic mechanism?
DNA break repair
Ataxia telangiesctasia DNA genetic mechanism? clinical feature
DNA break repair
biallelic LOF
high risk for blood cancer
DNA break repair system and associated diseases?
- ATM protein detects ds breaks (biallelic mutation –> ataxia telangiesctasia)
- ATM signals BRCA1/2 (mutation –> HBOC)
- BRCA2=FANCD1 (biallelic mutation –> fanconi anemia)
DNA recQ helicase family role? associated syndromes?
limits recombination
cancer susceptibility syndromes (3)
-Bloom (BLM)- most CA risks, death by 24, excess sister chromatid exchange
-Werner (WRN)- mesenchymal CA, excess translocation/del
-Rhothmund Thomson (RECQ4)- osteosarcomas, ploids and omies
PARP1
ssDNA break repair
works in parallel with BRCA/ATM/FANCD pathways
