genetic predisposition to adult onset disease

Question 1

ex. condition s with strong mendelian inheritence

Answer 1

Alzheimer’s
adult polycystic kidney disease
Huntington’s
CF

Question 2

ex conditions with multifactorial/polygenic inheritance

Answer 2

DM
Crohn’s
schizophrenia

Question 3

why are adults referrred to genetics for assessment

Answer 3

diagnosis
predictive testing 
carrier testing or cascade screening
FH 
fetal loss/recurrent misscarriages

Question 4

mechanisms of genetic adult onset disease

Answer 4

singe gene
chromosomal
mitochondrial
multifactorial: genetics, environmental

Question 5

prediction and uncertainty

Answer 5

• test info must be usable for Rx/prevention
• adequent info about uncertainty
• proper counselling
• 3rd parties should have no access
• kids only tested if potential medical benefits

Question 6

amytrophic lateral sclerosis

Answer 6

5-10% familial
autosomal
mean onset 55yrs
incomplete penetrance - no certainty

Question 7

ALS features

Answer 7

progressive muscle weakness, wasting 
inc reflexes
UMN and LMN signs
fasiculations
limb and bulbar muscles
death due to resp failure

Question 8

superoxide dismutase genes (SOD)

Answer 8

20% familial cases ALS
chromosomes 21, 6, 4

SOD1 - cytoplasm
SOD2 - mitochondria
SOD3 - extracellular

Question 9

what does SOD do

Answer 9

protect cells from free radical damage and tissue ischaemia damge
protect from progressive cellular degeneration

Question 10

huntington’s disease

Answer 10

full penetrance, no cure

mean onset late 30s/early 40s

Question 11

Huntington’s genetics

Answer 11

autosomal dominant

CAG expansion

Question 12

huntington’s features

Answer 12

movement: chorea, myoclonus, rigitidy, athetosis

cog change: poor planning + memory, subcortical demensia

psychiatric: depression, paranoia, psychosis

personality change: apathetic, self-centred, irritable, dishinibition