25 & 26 - Ethical Genetics Flashcards
Clinical geneticists
Overarching diagnosis for children with developmental delay / intellectual impairment, congenital abnormalities, growth disturbance and dysmorphic features
Ethical principles of genetic testing
- Autonomy
- Justice
- Beneficence
- Non maleficence
(AJBNM)
Autonomy
- Patient’s right to make a health care decision
- Must understand all risks and benefits (informed consent)
Justice
- Equal access of treatment / testing to all people
- Testing will not lead to discrimination of an individual
- Confidentiality
Beneficence
Intent of doing good for the patient
Non maleficence
Intent of causing no harm to patient
Genetic testing
- Diagnostic genetic testing
- Predictive / pre-symptomatic testing
- Carrier testing
- Screening for genetic disorders
Outcomes of positive results
- Management decisions
- Reproductive options
- Predictive testing for relatives
Outcomes of inconclusive result
Unable to offer predictive testing
Variant of uncertain significance
Unable to offer predictive testing
Predictive genetic testing
- Testing for a known mutation in family
- Definitive (neg or pos)
- Informed consent required
Testing in children
- Consider rights of child (a)
- Weigh up benefits and harms (B vs NM)
- Gudinhg principles
When is unconsented use allowed
Where it is reasonably necessary to lessen or prevent a serious risk to
the life, health or safety of any individual
Options for at risk couples
- Prenatal testing + termination of pregnancy
- Pre-implantation Genetic Diagnosis (PGD)
- Utilise Sperm or egg donor
- Adoption
Pre implantation genetic diagnosis
- Selection against an at risk single gene or chromosome
- Screening for aneuploidy
Genetic tech revolution
- 1990 (HGP, 13 years, $2.7 billin, thousands of scientists)
- 2013 (<1 week, <$1000, 1 scientist)
Whole exome sequencing
- Protein encoding regions of the
genome = exome - Most disease mutations are in coding (exons) or adjacent (splice sites)
Panel
- Cheaper, less analytical time, less data to store
- Higher throughput
- Better coverage of exons, better read depth
- Incidental findings avoided
WES
- Filter for genes of interest
- More expensive, more analytical time, more data to store
- Potential for incidental findings
- Able to go back and interrogate “new” genes
Issues with whole genome sequencing
- Incidental findings
- Beneficence vs non-maleficence?
- Medicalization of the genome
- Genetic discrimination
- Rights of the individual (autonomy) vs benefits of the community?
- Are doctors being paternalistic here?
On average how many loss of function variants does each person carry
250-300
% of false positives
27%
