New Treatments for Genetic Diseases Flashcards
What will be some likely future developments?
- Increased use of non-invasive prenatal diagnosis (Free foetal DNA in maternal plasma) for sex determination, testing for aneuploidies and paternal mutations
- Increased use of NGS,
- Increased understanding of varients with unknown significance and in the non-coding regions of genome,
- Improvements in NGS,
- More use of pharmacogenetics,
- More gene therapy,
- More precision medicine
What is precision medicine?
Use of DNA analysis to reduce side effects and increase efficacy of medicines
Name a current example where precision medicine is used?
Drugs such as Ivacaftor, tezacaftor and elxacaftor are used in cystic fibrosis to improve the CFTR protein function and reduce hospital admissions (they work on specific CF mutations)
Explain the mechanism of Ivacaftor
- Works on G551D mutation (3rd most common CF mutation) which blocks the opening of the CFTR chloride ion channel. Ivacaftor reopens the channel (thinning secretions)
How is genetic analysis used in cancer treatment?
Can help identify which therapies will be more suited for specific mutations.
What are some gene therapy strategies?
- Treating the gene or its expression,
- Replacing the gene
Explain gene editing
Done using the CRISPR- CAS9 system. They are designed to target a specific genomic sequence, then change or cut the DNA sequence. Need to be certain there will be no off-target effects.
How can you replace a faulty gene?
Zolgensma is a drug used for spinal muscular atrophy. A virus was genetically modified to contain a working copy of the mutated gene (SMN1 gene). Once injected into patient, the virus containing the gene will begin to produce relevant proteins.
What drug can be used in DMD and explain its mechanism
Ataluren is a drug which permits read-through of premature stop codons, allowing the ribosome to finish synthesising dystrophin
What is exon skipping?
Drugs that allows for mutated exons to be ‘skipped over’ during splicing.
