Discuss methods used in gene therapy, including the risks involved.

somatic cell therapy methods alter the genetic material of somatic cells/nongametes;
could cure the individual treated but disease can still be passed to offspring;
germ-line therapy methods alter the genetic material of sex-cells/gametes/sperm/eggs;
disease would be absent in future offspring;
retroviruses/viruses are used (as vectors);
to insert (normal) gene/allele (in host cells);
verified application, e.g. treatment of SCID (severe combined immunodeficiency);
no fully successful cases since relatively new / technical issues need to be solved e.g. ensure correct amount of gene product/at the right time/in the right place;
cases of gene therapy causing cancer in patients / infect healthy cells causing illness / harm other cell functions / e.g. (two) children treated for SCID developed leukaemia;
immune system may attack newly introduced viruses causing inflammation/toxicity/organ failure;

Points were awarded for use of viruses as vectors and for a possible risk of gene therapy. Some better candidates were able to give one verified example such as SCID. Very few were able to discuss somatic cell therapy and germ-line therapy. Candidates tended to confuse gene therapy with other genetic topics.