Clinical Genetics 3 Ethics and Genetics

Question 1

1. What is genetic information and what can be included under genetic information?

Answer 1

1. DNA based test
   - Detection of product of mutated gene
   - Family history e.g. Huntington’s, heart disease
   - Gender ?
   - Age ?

Question 2

Give the definition of a genetic test.

What are the steps in testing a DNA sample?

Answer 2

A test to detect the presence or absence of, or alteration in, a particular gene, chromosome or gene product, in relation to a genetic disorder

PCR amplification and then fingerprinting (‘bar codes’)

Question 3

1. List some primary principles in obtaining and handling genetic information?
2. List secondary principles

Answer 3

1. Genetic solidarity,
   altruism (selflessness and care for the welfare of others),
   respect for people
2. Confidentiality, privacy, consent, non-discrimination.

Question 4

1. What are the ethical issues when testing children?
2. When do you test for a ‘late onset disorder’?
3. Give an example of when childhood diagnosis is appropriate?

Answer 4

1. Need to have an EFFECTIVE TREATMENT e.g. childhood cancers (MEN-2, FAP)
   Don’t just test because the parents want to know - confidentiality, child may not want to know if they do/do not have an incurable condition
2. 18 years or older
3. Multiple Endocrine Neoplasia Type II (MEN-2)
   –> Medullary thyroid cancer
   –> C-cell hyperplasia
   –> Thyroidectomy is curative
   In this case genetic testing can be the SOLE indicator for surgery

Familial Adenomatous Polyposis Coli

• -> Autosomal dominant
• -> Mutations in APC gene on chromosome 5
• -> Causes thousands of polyps
• -> By age 15 >50% affected individuals will have multiple polyps - high penetrance

Question 5

Describe Gene testing in Huntington’s Disease.

What are some of the steps taken before doing a pre symptomatic or predictive test?

Answer 5

1. Diagnostic test confirms diagnosis in a symptomatic patient.
2. Presymptomatic predictive test: testing at risk of asymptomatic person.

• Set protocol for assessing attitudes to and knowledge of HD
• At least 2 sessions with a geneticist or genetic counsellor before testing

Question 6

1. Why is preimplantation genetic diagnosis performed?
2. What are the drawbacks?
3. If normal..?
4. If abnormal..?

Answer 6

1 - Parental choice
- May avoid termination of pregnancy for serious abnormalities

2. Cost, error, stress, travelling
3. .. implant the egg.
   - ->20-30% ‘take home baby rate/
4. … do not implant egg. Each disorder needs a licence from the HFEA.

Question 7

Give examples of some ethical issues surrounding genetic test results.

Answer 7

• Should employers have the results of genetic tests?
• -> Make the workplace safe rather than demanding a genetic test
• Should insurers have the results of genetic tests?
• -> Insurance Moratorium - government moratorium currently in place.
• Life insurance - no use to be made of genetic test results on policies up to £500,000
• Long-term care insurance, critical cover - no use to be made on policies up to £300,000
• Only one test approved - for HD gene.