Bio exp - genes

• Family studies 


  Used to investigate the genetic transmission of schizophrenia by comparing rates of schizophrenia in relatives of diagnosed cases and relatives of controls
• family studies pt2

  First-degree relatives (parents, siblings and offspring) share 50% of their genes. Therefore, if there is a genetic component to schizophrenia, we would expect to see higher rates of the disorder in relatives of diagnosed schizophrenics.
• twin studies

  Twin studies help to distinguish between the effects of nature and nurture.

  some of the most striking evidence for the genetic basis schizophrenia comes from looking at concordance rates between MZ and DZ twins.
• twin studies pt2

  Monozygotic twins (MZ) share all their genes, whilst dizygotic twins (DZ) share only 50% of their genes.

  In twin studies, a researcher compares the concordance rates for

  schizophrenia between MZ twins and DZ twins. If it is found that concordance rates are higher for MZ twins, then this difference should be due to genetic factors rather than environmental.
• the C4 gene

  The C4 gene is involved in eliminating the connections between neurons – a process called ‘synaptic pruning’. This happens naturally during teen years.

  Sekar et al. (2016) identified a complex variation of this gene which they believe increases the risk of schizophrenia
• the c4 gene pt 2


  This variation is thought to cause excessive or inappropriate pruning of

  neural connections which could lead to the development of schizophrenia. this would explain why schizophrenia symptoms often first appear during adolescence.