genetic basis of schizophrenia

• What does the genetic basis of schizophrenia suggest about inheritance?

  Biological characteristics are inherited from parents
• How does a faulty gene occur in relation to schizophrenia?

  It occurs due to random mutation
• What happens to a faulty gene after it occurs?

  It can be inherited by offspring
• What are candidate genes in the context of schizophrenia?

  Genes that contribute to the risk of developing schizophrenia
• What does the COMT gene control?

  It controls an enzyme that breaks down dopamine
• What happens if a person inherits a low activity variant of the COMT gene?

  Dopamine levels are allowed to increase
• What is linked to excessive dopamine activity in schizophrenia?

  Hallucinations experienced by some patients
• What does a polygenetic explanation propose about schizophrenia?

  Symptoms result from many candidate genes
• What is one method used to investigate the genetic basis of schizophrenia?

  Twin studies
• What types of twins are involved in twin studies for schizophrenia?

  Monozygotic and dizygotic twins
• What is calculated in twin studies when one twin has schizophrenia?

  Concordance rates
• What does a higher concordance rate for MZ twins suggest?

  Schizophrenia has a genetic basis
• What percentage of genetic material do MZ twins share?

  100%
• What percentage of genetic material do DZ twins share?

  Approximately 50%
• What did Gottesman (1991) find regarding concordance rates?

  MZ twins had 48%, DZ twins had 17%
• What does the difference in concordance rates between MZ and DZ twins suggest?

  Schizophrenia is at least partly genetic