Lecture 45 Flashcards
What types of mutations can karotyping detect?
Can detect deletions, duplications, inversions, translocations, other abnormalities
only large differences can be detected
What does a metracentric chromosome look like?
the centromere is in the middle
what does a submetracentric chromosome look like?
the centomere is not in the middle
what does an acrocentric chromosome look like?
presence of satellites
What can FISH probes detect?
Numerical chromosome aberrations
- Deletions
- Translocations
- Gene amplification
FISH probes are large
What is chromosome painting useful for?
can show translocation and rearrangements
very useful in cancer genetics
each chromosome is a diff color
What a the three types of euploidy?
- diploidy
- triploidy
- tetraploidy
diploidy?
normal
triploidy?
not compatible with life
tetraploidy?
lethal
What are the two types of aneuploidy?
- monosomy
2. trisomy
monosomy?
not compatible with life
exception: monosomy of X chromosome
trisomy?
one additional chromosome (47)
Trisomy 21?
down syndrome
symptoms of down syndrome?
intellectual disability, short stature, heart defects, depressed nasal bridge
risk factors of down syndrome?
increased maternal age (meiosis 1 non-disjunction)
Trisomy 18?
Edward syndrome
nondisjunction during oogenesis
symptoms of trisomy 18?
clenched fist, overlapping fingers
rocker bottom feet
heart defects
microcephaly
intellectual disability
Trisomy 13?
Patau syndrome
nondisjunction during oogenesis
features of trisomy 13?
- polyadctyly
- cleft lip and palate
- microcephaly
- intellectual disability
- cardiac abnormalities
how does turners syndrome occur?
nondisjunction during spermatogenesis
What is mosaicism?
The presence of two or more populations of cells
in one individual with different genotypes
