1
Q
Unipareental Disomy
A
- Occurs because of a meotic nondisjunction that results in 2 alleles being inhereted from one parent.
- Euploid, but principles of mechanism can be applied to trisomy
2
Q
Meosis
A
- 2N 2C (AB) Replication
- 4N 2C (AA BB) Meosis I division (segredation)
- 2n 1c (AA) (BB) Meosis II division
- 1n 1c (A) (A) (B) (B)
3
Q
Meosis I Error
A
- Results in (AA BB) and ()
- Problem in segregation, further meosis II normal division leads to
- (AB) (AB)
- This is a heteroplasmic division, leading to heterodisomy
4
Q
Meosis II Error
A
- from (AA) to (AA) ()
- This results in homodisomy
5
Q
HW populations genetics
A
p^2 + 2pq + q^2 = 1 and p+q = 1
- Drawing punned square, there are two possibilities for a heteroygote carrier, therefor when determining frequency use 2pq
- Heterozygote carrier: 2pq
- Homozygote recessive: q^2
- Homozygote Dominant: p^2
6
Q
Lebers Optic Neuropathy
A
Degeneration of retinal ganglion cells leading to blindness as an adult
7
Q
MERRF
A
- Myoclonic epilepsy, hearing loss, lactic acidosis and exercise intolerance
- Ragged Red Fibers
8
Q
MELAS
A
-Lactic acidosis, muscle weakness and stroke like episodes that present before the age of 40
9
Q
Autosomal Dominant Disorders
A
AIP, PCT, Achondroplasia, APKD, Tuberous Scloerosis, VHL , NF 1 and 2, HHT,
-Hypercholesterolemia, FAP, spherocytosis, marfans
10
Q
Cystic Fibrosis
A
- Most commonly due to defeect in 508F which leads to a misfolded protein that is degraded
- Normally a Cl channel that resorbs Cl in sweat and secretes it in GI and Lungs
- Defect leads to thick mucous because of lack of osmotic pressure
- Salty baby with increased Cl on sweat test
- Male infertility due to lack of ductus deferens
11
Q
XLR
A
Brutons and wiskott aldrich, CD40L, many immunologic
12
Q
Trinucleotide
A
Myotonic dystrophy and the rest
-Errors in methylation??
