genetic explanation to schizophrenia

Question 1

what is a genetic explanation

Answer 1

suggests the disorder is due to your genes, it has a biological basis which can be inherited and passed through generations.

would suggest that the more genes shared with someone with schizophrenia the higher the likelihood of developing it.

Question 2

why do we do twin and family studies

Answer 2

measures concordance rates to assess to what degree a particular trait/disorder is inherited within family’s which tells us whether there is a genetic basis.

Question 3

outline Gottesman’s study and key findings

Answer 3

conducted a large scale family study, found 48% concordance rates for MZ, 17% for DZ

Question 4

evaluate what Gottesman’s study tells us (AO3)

Answer 4

MZ share 50% more of their genes than DZ therefore we could expect a concordance rate of about half for DZ. Prevalence is only 1% so high % found in the data tells us there must be a biological basis to SZ.
However if truly biological would expect 100%. Never found must be another factor eg. environment.
perhaps it was the shared environment and biology that accounts for an inflated concordance rate.
Impossible to separate nature and nurture.

Question 5

what are candidate genes

Answer 5

individual genes believed to be associated with an increased risk of schizophrenia through inheritence.

Question 6

give an example of a candidate gene and its function

Answer 6

PCM-1
associated with function of neurotransmitters such as dopamine.

Question 7

schizophrenia is not caused by one single gene, therefore it can be described as what?

Answer 7

polygenic

Question 8

outline a study that demonstrates schizophrenia is polygenic (AO1/AO3)

Answer 8

Ripke et al combined data from previous genome-wide studies of SZ. comapred the genetic makeup of 37,000 ppl with SZ and compared to controls
found 108 separate genetic associations were associated with increased risk of SZ

Question 9

Schizophrenia can be described as aetiologically heterogeneous, what does this mean

Answer 9

a number of different combinations of genes can lead to the illness.

Question 10

Schizophrenia has also been found to have a genetic origin in the absence of family history, what is an explanation for this, what support is there.

Answer 10

Gene mutation is more likely to occur with age, found positive correlations between paternal age and risk of schizophrenia. from 0.7% with fathers under 25 to 2% with fathers over 50. Could cause a biological predisposition if passing on mutated genes to offspring.