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PUID: 64 || PLAB 2 Mock 3 :: CounselingCondition10: Huntington's Disease (1st Attempt)


Summary

This PLAB 2 counselling scenario focuses on explaining Huntington’s disease inheritance, assessing family history, discussing genetic testing, and addressing concerns about future children. Candidates are expected to communicate complex genetic concepts in simple language while demonstrating empathy, structured counselling, and patient-centred communication.



Key Points


Understanding Huntington’s Disease

  • Huntington’s disease is a neurodegenerative genetic disorder.

  • It follows an autosomal dominant inheritance pattern.

  • Only one faulty gene copy is enough for the disease to manifest.

  • Patients commonly present with:

    • Psychiatric symptoms initially

      • Depression

      • Anxiety

      • Irritability

      • Behavioural changes

    • Later neurological symptoms

      • Chorea

      • Coordination difficulties

      • Eye movement abnormalities

      • Cognitive decline

  • Typically presents between 35–50 years, although earlier onset may occur due to anticipation.



Genetic Inheritance Explanation


Autosomal Dominant Inheritance

  • Every person inherits:

    • One gene copy from the mother

    • One gene copy from the father

  • In Huntington’s disease:

    • A single faulty gene can cause disease manifestation.

  • If one parent is heterozygous:

    • Child has a 50% chance of inheriting the faulty gene.

  • If the affected parent is homozygous:

    • There is a 100% inheritance risk.


Important Clarifications

  • There is no carrier state in autosomal dominant disorders.

  • Patients either:

    • Have the faulty gene and may develop disease

    • Or do not have the gene at all.

  • Family history should extend to:

    • Parents

    • Grandparents

    • Maternal and paternal sides separately.


Punnett Square Explanation

Candidates should be able to explain inheritance visually and simply:

  • Avoid using technical jargon without explanation.

  • Explain:

    • “One faulty copy is enough to cause disease.”

    • “This is why the condition runs strongly through families.”



Important Considerations


Communication in Counselling Stations

  • Avoid excessive jargon.

  • Explain “autosomal dominant” in plain English.

  • Use diagrams/Punnett squares where appropriate.

  • Avoid memorised robotic phrases.

  • Show natural empathy and active listening.


Common PLAB 2 Pitfalls

Avoid:

  • Overusing phrases like:

    • “Everything will remain confidential.”

    • “Is that okay?”

    • “May I ask personal questions?”

  • Sounding rehearsed or scripted.

  • Overloading patients with scientific terminology.

  • Giving inaccurate inheritance percentages.

  • Assuming facts without exploring family history.


Age of Onset & Anticipation

  • Huntington’s usually manifests later in life.

  • Younger patients may still be asymptomatic.

  • Anticipation:

    • Disease can present earlier in successive generations.

    • Important counselling point in family discussions.



Diagnostic Approach


Step-by-Step Counselling Structure


1. Build Rapport

  • Confirm name and age.

  • Acknowledge concerns empathetically.

  • Explore ICE:

    • Ideas

    • Concerns

    • Expectations


2. Explore Presenting Concerns

Ask:

  • Why they attended today

  • What worries them most

  • Whether symptoms are present


3. Focused History

Explore:

  • Family history

    • Maternal side

    • Paternal side

    • Grandparents

  • Neurological symptoms

  • Psychiatric symptoms

  • Functional impairment


4. Explain Inheritance

  • Use simple language.

  • Explain dominant inheritance.

  • Clarify probability carefully.

  • Use visual aids if needed.


5. Discuss Investigations

  • Genetic testing

  • Genetic counselling referral

  • Neurology referral if symptomatic


6. Address Reproductive Concerns

Discuss:

  • Risk to children

  • IVF with PGD

  • Prenatal testing

  • Adoption options


7. Safety Net & Follow-Up

  • Offer psychological support.

  • Encourage follow-up appointments.

  • Provide support groups/resources.



Management


Investigations

  • Genetic testing for Huntington’s gene mutation

  • Neurological assessment

  • Psychiatric evaluation if symptoms present


Specialist Referrals

  • Genetic counsellor

  • Neurologist

  • Psychiatrist if needed

  • Fertility specialist for PGD discussions


Reproductive Options

Preimplantation Genetic Diagnosis (PGD)

  • IVF performed.

  • Embryos genetically tested.

  • Only unaffected embryos implanted.

  • Important counselling regarding:

    • Cost

    • Success rates

    • Emotional burden

    • Ethical implications

Prenatal Testing

  • Chorionic villus sampling

  • Amniocentesis

Alternative Options

  • Adoption

  • Remaining child-free by choice



Communication Skills


What Examiners Want

  • Genuine interaction

  • Clear explanations

  • Logical structure

  • Natural empathy

  • Active listening


Excellent Phrases

  • “I can understand why this is worrying for you.”

  • “Let me explain this step by step.”

  • “Would it help if I drew this out visually?”


Avoid

  • Scripted empathy

  • Excessive reassurance

  • Technical jargon without explanation



Ethical Considerations


Key Ethical Areas

  • Informed consent for genetic testing

  • Psychological impact of predictive testing

  • Confidentiality

  • Family implications of genetic information

  • Reproductive autonomy


Good Medical Practice Principles

Candidates should demonstrate:

  • Respect for patient autonomy

  • Shared decision-making

  • Compassionate communication

  • Clear explanation of risks and uncertainties

  • Non-directive counselling



PLAB 2 Examiner Tips Relevant to This Station


Strong Candidates

  • Stay focused on the task.

  • Use structured counselling.

  • Tailor explanations to the patient’s understanding.

  • Manage time effectively.

  • Explain complex concepts simply.


Weak Candidates

  • Give memorised speeches.

  • Ignore patient concerns.

  • Over-investigate unnecessarily.

  • Speak unnaturally.

  • Fail to explain terminology.




Additional Resources

  • GMC Good Medical Practice guidance

  • GMC PLAB 2 examiner guidance

  • GMC examiner top tips document

  • PLAB 2 communication and counselling frameworks

  • NICE guidance on Huntington’s disease management

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