Bioinformatics is the collecting, processing and analysis of biological information and data using computer software.Bioinformatics build databases which hold gene sequences and sequences of complete genomes. These sequences can be matched --> calculate degrees of similarity (close similarities indicate recent common ancestry)
- human genes may be found in other organisms and are used to model for investigating the way in which such genes have their effects
- e.g.: Plasmodium genome: used to find new methods to control parasites
---> reading the gene sequences provides information to develope vaccines for malaria
Advantages of using human proteins produced from recombinant DNA
1. Insulin
- reliable supply available for increasing demand
- is not dependent on factors e.g.: meat trade
- acts faster than animal insulin or slower over a long period of time
2. Factor VIII - genetically modified hamster cells produce factor VIII
- Factor VIII is extracted and purified before being used to treat patients with haemophilia
- avoids the risk of infection e.g.: HIV from donated blood
3. adenosine deaminase (ADA) - used to treat SCID (severe combined immunodeficiency disease)
- produced from genetically modified larvae of cabbage looper moth caterpillar
- administered to patients when:
- waiting for gene therapy
- gene therapy is not possible
Syllabus 2016-2018 19.2 Genetic technology applied to medicine a) define the term bioinformatics b) outline the role of bioinformatics following the sequencing of genomes, such as those of humans and parasites, e.g. Plasmodium (details of methods of DNA sequencing are not required) c) explain the advantages of producing human proteins by recombinant DNA techniques (reference should be made to some suitable examples, such as insulin, factor VIII for the treatment of haemophilia and adenosine deaminase for treating severe combined immunodeficiency (SCID)) d) outline the advantages of screening for genetic conditions (reference may be made to tests for specific genes such as those for breast cancer, BRCA1 and BRCA2, and genes for haemophilia, sickle cell anaemia, Huntington’s disease and cystic fibrosis) e) outline how genetic diseases can be treated with gene therapy and discuss the challenges in choosing appropriate vectors, such as viruses, liposomes and naked DNA (reference may be made to SCID, inherited eye diseases and cystic fibrosis) f) discuss the social and ethical considerations of using gene testing and gene therapy in medicine (reference should be made to genetic conditions for which treatments exist and where none exist, also to IVF, embryo biopsy and preselection and to therapeutic abortions) g) outline the use of PCR and DNA testing in forensic medicine and criminal investigations |
