Genetics - Predisposition to Adult Disease Flashcards
Why are adults referred to clinical genetics?
Diagnosis of disease Predictive testing Cascade screening Family history Fetal loss/miscarriages
What are the main mechanisms of adult onset genetic disease?
Single gene Chromosomal Mitochondrial Multifactorial Environment
What are the main ethical principles of medicine?
Respect for autonomy
Beneficence
Non-maleficence
Justice
What are the requirements of Predictive testing?
Test information must be usable for prevention/treatment
Information on test uncertainty
Proper counselling
Children only tested if there are benefits
Third parties have no access
What is the familial connection for Motor neurone disease?
5-10% familial
What is the mean age of onset for ALS?
55yrs
younger in familial forms
What are the clinical features of ALS?
Progressive muscle weakness/wasting Increased reflexes Limb/bulbar muscle involvement Motor signs Fasciculations Cognition spared
What is the most common cause of death in ALS?
Respiratory failure
What is the pathophysiology of ALS?
Cu/Zu superoxide dismutase
Excess of enzyme in motor neurones
What are the forms of SOD seen in humans? And where are they located?
SOD1 (cytoplasm)
SOD2 (mitochondria)
SOD3 (extracellular)
SOD1/3 contains what?
Copper, Zinc
SOD2 contains what?
Manganese
The genes for SOD are contained on which chromosomes?
21, 6, 4
What is the role of SOD?
Protect cells from free radical/ischaemic damage and progressive cell degradation
What mutation is seen in Huntington’s disease?
CAG expansion
