Genetic Counselling

Question 1

What is genetic counselling?

Answer 1

A communication process which deals with human problems associated with the occurrence, or the risk of occurrence, of a genetic disorder in a family’.

Question 2

What is the role of a genetic counseller?

Answer 2

Comprehend the medical facts, including the diagnosis

Understand the way in which heredity contributes to the disorder, and the risk of recurrence in relatives

Explore the alternatives for dealing with the risk of recurrence

Choose the course of action which seems to them appropriate

Make the best possible adjustment to the disorder in an affected family member and/or the risk of recurrence of that disorder

Question 3

What information needs to be gathered at a consultation?

Answer 3

Medical and social history

Family history, ages at diagnosis etc

Confirmations of diagnoses, genetic test reports

Question 4

What information is given at a consultation?

Answer 4

The condition

Inheritance patterns

Occurrence/Recurrence risks

Question 5

What options are offered at a consultation?

Answer 5

Whether or not to have a genetic test (diagnostic/predictive/carrier/prenatal)

Screening and preventative options

Reproductive options

Question 6

Issues to be aware of in a consultation?

Answer 6

• Loss and Grief
• Guilt and Blame
• Family myths and beliefs
• Culture and religious beliefs
• Confidentiality and informed consent
• Distress – can be a sign that someone is not adjusting to a situation

Question 7

Grief and loss around childhood and adolescence?

Answer 7

Birth of a child with disabilities, loss of the perceived child

Loss of an infant e.g. Tay Sachs

Loss of young adult e.g. CF, FAP

Illness of a parent e.g. HD, cancer

Question 8

When would genetic testing be offered?

Answer 8

Genetic testing following confirmation that they have inherited a faulty gene or notice symptoms e.g. Huntington’s

Question 9

Grief and loss surrounding genetic testing results?

Answer 9

Loss of a ‘part’ - genetic testing may lead a person to confront surgery i.e. mastectomy or colectomy e.g. BRCA1 gene or FAP gene

Survivor guilt when they get a good predictive result

Question 10

Issues with family dynamics?

Answer 10

Old wounds and concealed hatreds may be expressed

Difficulty in re-contacting an estranged branch of the family

Refusal to give consent for medical information

Reluctance to tell other family members a diagnosis

Question 11

What is transcultural genetic counselling?

Answer 11

Transcultural genetic counselling is not about being an expert on any given culture, rather it is a way of thinking about patients that acknowledges and values culture:

• Belief and disbelief about science, invasive testing, postmortem
• Pressures to have children
• Communication in correct language
• Beware of making assumptions e.g. that termination of pregnancy would not be acceptable

Question 12

When testing children for adult-onset conditions, what questions should be asked?

Answer 12

• Can it wait until older?
• Will it cause insurance problems?
• Are there treatments or any benefits to knowing?
• Will their autonomy be respected?
• Do they know enough to understand what is happening?
• Are the parents making the decision without the child’s involvement?

Question 13

What is amniocentesis?

Answer 13

Amniocentesis is a procedure in which amniotic fluid is removed from the uterus for testing or treatment. This fluid contains foetal cells and various proteins.

Question 14

What does amniocentesis test for?

Answer 14

Foetal abnormalities (birth defects) such as Down syndrome, cystic fibrosis or spina bifida.

Question 15

Who is amniocentesis offered to?

Answer 15

Only offered to pregnant women who have a higher chance of having a baby with a genetic or chromosomal condition

Question 16

What is chorionic villus sampling?

Answer 16

A small sample of cells (called chorionic villi) is taken from the placenta where it attaches to the wall of the uterus

Question 17

What does CVS test for?

Answer 17

To check if your baby has a genetic or chromosomal condition, such as Down’s syndrome, Edwards’ syndrome or Patau’s syndrome.

Question 18

Who is CVS offered to?

Answer 18

Only offered to pregnant women with an increased risk of having a baby with a genetic or chromosomal condition

Question 19

What is PGD?

Answer 19

Pre-implantation genetic diagnosis.

A treatment which involves checking the genes or chromosomes of your embryos for a specific genetic condition.

Question 20

Why is PGD complex?

Answer 20

Because the embryos need to be tested in a lab, you will need to have IVF.

Embryos which have been tested and are free of the condition will be placed back into your womb to hopefully continue to develop

Question 21

Who is offered PGD?

Answer 21

you have ended previous pregnancies because of a serious genetic condition

you already have a child with a serious genetic condition and want to avoid this happening again

you have a family history of a serious genetic condition, or

you have a family history of chromosome problems.

Question 22

What conditions does PGD test for?

Answer 22

PGD can be used to test for almost any genetic condition where a specific gene is known to cause that condition.

Question 23

Risks of amniocentesis / CVS?

Answer 23

Slight risk of miscarriage (larger in CVS)

Also have to face tough decision - termination?

Question 24

Diagnostic challenge for childhood congenital deafness?

Answer 24

50% genetic cause

50% other causes (prematurity, infection during pregnancy, childhood infection)

Question 25

Of the 50% of congenital childhood deafness, how many are syndromic? How many are nonsyndromic?

Answer 25

Syndromic - 30%

Nonsyndromic - 70%

Question 26

What is syndromic hearing loss?

Answer 26

syndromic hearing loss occurs with signs and symptoms affecting other parts of the body

Question 27

What is nonsyndromic hearing loss?

Answer 27

Hearing loss is a partial or total loss of hearing that is not associated with other signs and symptoms.

Question 28

Of the nonsyndromic cases of hearing loss, what types of inheritance are they caused by?

Answer 28

• 75-85% recessive genes
• 10-15% dominant genes
• 5-15% X-linked genes or mitochondrial inheritance

Question 29

What is usher syndrome?

Answer 29

Primarily characterised by deafness accompanied by retinitis pigmentosa

Question 30

What is FAP?

Answer 30

Familial adenomatous polyposis (FAP) is a dominantly inherited predisposition to the development of many hundreds to thousands of adenomatous polyps of the colon.

Question 31

What is the mean age of onset of FAP? How would this affect genetic testing?

Answer 31

The mean age of onset is around 15 years, symptoms may arise in the third decade, and the median age for the development of colonic cancer is 35–40 years.

Reduces age of testing –> testing earlier is better.

The suggested age of testing is around 12.

Question 32

What is exclusion testing?

Answer 32

Exclusion testing means that the at-risk parent doesn’t have to have a genetic test to have disease-free children.

E.g. Huntington’s:
Exclusion testing involves testing a foetus (unborn baby) around 10-15 weeks into a pregnancy to see if it has the tracking marker for Huntington’s but NOT testing parent