genetic variation and disease Flashcards
how is a chromosome recognised
centromere in between short-p and long-q telomere
total number of chromosmes
46
which arm doesnt rlly matter
short arm
balanced chromsome rearrangement
all chromosome material is present just in a different arrangement
unbalanced chromosme rearrangement
extra or missing chormosomal material
usually 1 or 3 copies of same genome
aneuploidy
whole exrta or missing chromosome
translocation
rearrangement of chromosomesnseet
insertions/ deletions
missing or duplicated material
downsydrome
47XY +21
robertsonian translocation
two accrocentric chromosomes stuck end to end
trisomy 21
downsydorme
trisomy 14
miscarriage
edwards syndrome
47XY + 18
turner syndrome
45X
why is x chromosome aneuploidy better tolerated
due to x inactivation
FISH
Uses fluorescent probes that bind only to parts of a nucleic acid sequence with a high degree of sequence complementarity
For finding specific features
aCGH
- 1st line chromosome test
- Detects missing/duplicated pieces of chromosome
- Find polymorphisms
- Does not detect balanced rearrangements
- whole chromosme aneuploidies
mosaicism
when a person has two geentically different sets of cells in their body
PCR
rapid amplification of DNA
first lin efor chromosome imbalance
aCGH
what doesnt detect balanced rearrangement
aCGH
autoimmune disease associated with single gene defect
IPEX
