Genetics in Ageing and Health Flashcards
What is ageing?
Progressive loss of function accompanied by decreasing fertility and increasing mortality with advancing age.
What is the main mechanism behind ageing?
Accumulation of damage due to free radical and oxidative stress.
Why is understanding chronic disease so important?
Chronic diseases are the major cause of death and disability in the world – estimated at around 70%
What is the major risk factor for chronic disease?
Age
What suggests there are genes for ageing?
Diversity in longevity between species.
Is ageing programmed?
NO
Why is there a limit on lifespan?
Extrinsic mortality
Genes are selected to ensure survival for expected lifespan and no more
What is the selection shadow theory?
Late-acting deleterious mutations may accumulate due to being advantageous at a younger age.
What are genes with age pleiotropy?
Selection will tend to advance good and postpone bad effects
What is the disposable soma theory of ageing?
Differences in longevity between species can be explained by different levels of resource allocation to maintenance.
What happens when you reduce insulin like signalling?
Enhances survival is associated with longevity.
What is the caloric restriction evidence for plasticity in ageing?
Causes a delay in age-related disease due to a cellular stress response but a reduction in fertility.
What is the twin evidence for a genetic contribution to ageing?
Comparing the longevities of mono- and di-zygotic twins suggests that genes explain 25% of the variability in longevity.
What are progeroid syndromes?
Single gene mutations but affect multiple areas.
What kind of progeroid syndromes result from gene mutations
involved in DNA repair?
Werners
Blooms
Cockayne
What is WRN?
An autosomal recessive gene encodes a DNA helicase.
What are the symptoms of damage to the WRN (Werner syndrome Helicase)?
Osteoporosis
Cataracts
Cardiovascular disease
Grey hair
What is Hutchinson-Gilford caused by?
Caused by de novo autosomal dominant mutation in LMNA which encodes lamin A.
What does the mutation in LMNA cause?
Irregular nuclear envelope?
What are the symptoms of Hutchinson-Gilford?
Athersclerosis
Sarcopenia
Osteoporosis.
What is NOT a symptom of WRN damage?
Neurodegeneration
Alzheimer’s disease
What is NOT a symptom of Hutchinson-Gilford?
Dementias
Cancer
