Biological explanation: genetic inheritance

Question 1

Ripke et al

Answer 1

• 108 genetic variants that could mediate a vulnerability to the disorder
• includes variations on chromosome 8 and 11 and the C4 gene

Question 2

Hong et al

Answer 2

• variation on the gene TPH was far more common with chinese patients with schizophrenia

Question 2

Gottesman and Shields

Answer 2

• family studies about chance of developing disorder if their relative has schizophrenia
  -> children of 2 schizophrenic patients: 46%
  -> identical twins: 48%
  -> first-degree relatives: 13%
  -> second-degree relatives: 5%
  -> normal person: 1%

Question 3

MacDonald and Schultz

Answer 3

• if one MZ twin is diagnosed with schizophrenia, the other twin is 99 times more likely to suffer from the condition

Question 4

Tienari et al

Answer 4

• adoption study in Finland with 164 adopted children
• group 1:
  -> biological mothers had been diagnosed with schizophrenia
  -> 7% were then diagnosed with schizophrenia
• group 2:
  -> biological mothers did not have schizophrenia
  -> 2% were then diagnosed with schizophrenia

Question 5

Joseph et al

Answer 5

• 40% concordance rate for MZ twins
• 7% concordance rate for the DZ twins