Woman Requesting Pre-conceptual Advice Due to Family History of Duchenne Muscular Dystrophy — Free SCA Practice Case
Woman requesting pre-conceptual advice due to family history of Duchenne Muscular Dystrophy
Station Timer
Golden Minute
Initial Introduction
•Introduce yourself
•Ask an open question — "How can I help you today?"
•Listen — don't interrupt
•Catch early cues
Data Gathering
History, ICE & Diagnosis
Clinical Management
Diagnosis, Plan & Decisions
Safety Net
Follow-up & Close
Five cases are free: a live 12-minute consultation with an AI patient each, marked, and no card.
Materials for Candidate
Please review before starting the consultation
Full Name
Chloe Davies
Age
28 years
Consultation Type
VideoAge
28
Reason for Encounter
"Patient and her husband are thinking about starting a family. She is requesting advice because her nephew was recently diagnosed with Duchenne Muscular Dystrophy."
Medical Records
- ●PMH: Asthma (mild, infrequent inhaler use).
- ●Medications: Salbutamol inhaler PRN. Microgynon 30 (Combined Oral Contraceptive Pill).
- ●Allergies: Penicillin (Rash).
- ●Social: Non-smoker, drinks 4 units/week. Works as a primary school teacher.
Recent Notes
- ●Last Month: Asthma review. Well controlled.
Patient Script
For the friend playing the patient role
Character Overview: You are Chloe. You and your husband have been married for two years and were planning to stop taking your contraceptive pill this month to try for a baby. However, your world was shaken three months ago when your older sister's 4-year-old son, Leo, was diagnosed with Duchenne Muscular Dystrophy (DMD). You have seen the devastation this has caused and are terrified of passing the same condition to your own child.
Opening Sentence: "Hi Doctor. My husband and I were planning to start trying for a baby this month, but we've had to put the brakes on. My sister's little boy was just diagnosed with Duchenne Muscular Dystrophy. We are heartbroken for them, but now I'm terrified I might carry the same gene. What do I need to do?"
History if Asked (Data Gathering Phase)
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The Family History (Crucial Genetic Link):
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"It's my older sister's son, Leo. He's 4. He was late walking and kept falling over."
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"My sister had a blood test last month, and the hospital told her she is a 'carrier' of the faulty gene."
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"We have a younger brother, and he's completely fine and healthy."
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"Our mum and dad are healthy, but my mum's brother (my uncle) died in his teens. We never really talked about it, they just said he had 'weak muscles'." (Classic X-linked history).
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Current Status:
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"I'm still taking my contraceptive pill. I haven't missed any."
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"I'm taking Folic Acid tablets from the supermarket because my friend told me to."
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General Pre-conceptual Health:
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"I don't smoke. I only drink a glass of wine on the weekends."
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"My asthma is absolutely fine, I rarely use my blue inhaler."
ICE — Ideas, Concerns, Expectations
The patient does not volunteer these unprompted. They surface only when the candidate directly explores her perspective.
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Ideas: "I know it's something genetic — my sister said it's passed through the mother's side. I think because we're sisters, there's a chance I could have the same faulty gene. I just don't know how likely it is or how to find out."
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Concerns: "Honestly, I'm terrified. I've watched what this has done to my sister and Leo — he's only 4 and they're already talking about wheelchairs. I can't put a child through that. And I'm worried that if I do carry it, does that mean we can never have a healthy baby? My husband and I have been dreaming about this for years and now it feels like it's all falling apart."
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Expectations: "I just want someone to tell me clearly what my options are. Can I get tested? And if I am a carrier, is there a way to still have a baby that won't be affected? I need a plan — I can't just sit with this uncertainty."
If Asked — Medical History and Medications
Actor guidance for items from the medical records that the candidate may ask about.
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Microgynon 30 (Combined Oral Contraceptive Pill): "Yes, I've been on the pill for about six years now. No problems with it. We were planning to stop it this month to start trying, but then all of this happened with Leo so I've kept taking it. I wanted to get advice first before we did anything."
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Salbutamol inhaler: "I've got a blue inhaler but I barely use it — maybe once every couple of months if I'm doing a lot of running around at work with the kids. It's not been an issue at all."
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Penicillin allergy: "Yes, I came out in a rash when I was a child — I think I was about 8. They told my mum not to give it to me again. I've never had any other problems with medicines."
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Recent asthma review: "I went to the nurse last month for my asthma check. She said everything was fine — my peak flow was normal and I didn't need to change anything."
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Folic acid: "My friend who had a baby last year told me I should start taking folic acid before trying to conceive. I've been taking the 400 microgram ones from Tesco for about a month now."
Social History and Lifestyle Impact
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Occupation and daily life: "I'm a primary school teacher — Year 1, so they're 5 and 6 year olds. I love my job. My husband works in IT. We've got a nice little house and we were so ready for this next step."
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Impact of the situation on daily life: "It's taken over everything, honestly. I can't concentrate at work — I'm surrounded by little children all day and all I can think about is Leo and what might happen if we have a baby. I cried in the staff toilets last week because one of my boys fell over in the playground and I just thought of Leo struggling to walk. My husband and I talk about it every night but we just go round in circles. We were supposed to be excited about starting a family and instead it feels like a nightmare."
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Relationship with sister: "My sister and I are really close. I've been going over to help with Leo every weekend. She's been amazing but I can see it's breaking her. She told me I need to get tested before we try — she doesn't want anyone else in the family to go through what she's going through."
If Asked — Associated Symptoms
Actor guidance for clinical questions a candidate may ask. The patient does not volunteer these.
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If asked about any muscle weakness or difficulty with physical activity herself: "No, nothing like that. I'm fine physically — I can keep up with 30 five-year-olds all day, so I think I'm alright on that front."
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If asked about any problems with her periods or menstrual cycle: "No, my periods are regular — every 28 days, like clockwork while I've been on the pill. Before the pill they were regular too, maybe every 30 days or so. No heavy bleeding or anything like that."
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If asked about any heart problems or palpitations: "No, nothing like that at all."
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If asked about any fatigue or tiredness: "I mean, I'm a teacher, so I'm always tired by Friday — but nothing unusual or medical, no."
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If asked about any mood changes, anxiety, or depression: "I wouldn't say I'm depressed, but I've definitely been more anxious and tearful since Leo's diagnosis. It's all situational though — I was absolutely fine before this happened."
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If asked about any previous pregnancies or miscarriages: "No, I've never been pregnant. We've always been careful."
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If asked about her husband's family history of muscle problems or genetic conditions: "No, his family are all healthy as far as we know. No muscle problems or anything like that on his side."
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If asked about cervical screening: "Yes, I had a smear test about a year ago and it was normal."
Responses to Management (The Negotiation Phase)
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If the Doctor asks you to explain what you know about the genetics: Reaction: "My sister tried to explain it. Something about boys getting the disease and women just carrying it? But I share blood with my sister, so does that mean I definitely have it?"
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If the Doctor suggests referring to Clinical Genetics: Reaction: "Yes, please. How long will that take? Should we stop trying for a baby until we get the results?"
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If the Doctor advises coming off the pill now: Reaction: Anxious. "But what if I get pregnant before I have the genetic test? I couldn't bear the thought of having a sick baby. Is there a way to make sure a baby doesn't have it?"
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If the Doctor discusses standard pre-conceptual advice (e.g., Folic acid, smoking) but ignores the genetics: Reaction: Frustrated. "I know about vitamins, Doctor, but my main worry is this muscle disease. Are you going to test me for it?"
Mark Scheme
Domain 1: Data Gathering and Diagnosis
Domain 2: Clinical Management and Medical Complexity
Domain 3: Relating to Others
Clinical Learning Points
DMD Genetics and X-Linked Inheritance
- ●Inheritance pattern: DMD is caused by mutations in the DMD gene on the X chromosome and follows an X-linked recessive pattern. Females carry two X chromosomes; if one carries the mutation, the second healthy X usually compensates, making most carrier females clinically unaffected (though some manifest mild muscle weakness or cardiomyopathy — so-called 'manifesting carriers').
- ●Why males are affected: Males have only one X chromosome. If they inherit the mutated X from a carrier mother, there is no backup and they develop the disease. This explains why DMD almost exclusively affects males.
- ●Reading the pedigree: The key features that point to X-linked recessive inheritance are: an affected male (Leo), a confirmed carrier mother (the sister), and a maternal uncle who died in his teens with 'weak muscles.' This pattern — affected males on the maternal side across generations — is the classic X-linked pedigree signature.
- ●De novo mutations: Approximately one-third of DMD cases arise from a new (de novo) mutation. However, because Chloe's sister has been confirmed as a carrier through genetic testing, this is a familial case — de novo mutation is not the relevant explanation here.
Chloe's Carrier Risk
- ●Starting risk: Because her sister is a confirmed carrier and the maternal uncle almost certainly had DMD, their mother is very likely to be a carrier herself. As the daughter of a likely carrier, Chloe has approximately a 1 in 2 (50%) chance of having inherited the mutated X chromosome.
- ●This is a probability, not a certainty: Genetic testing will give a definitive answer. Roughly half of women in Chloe's position will test negative — this is an important point to communicate clearly, as it provides genuine grounds for hope without minimising the uncertainty.
- ●If Chloe is confirmed as a carrier: Each pregnancy carries the following risks — 1 in 4 chance of an affected son, 1 in 4 chance of an unaffected son, 1 in 4 chance of a carrier daughter, 1 in 4 chance of a non-carrier daughter. In practice this means a 1 in 2 chance that any son will be affected, and a 1 in 2 chance that any daughter will be a carrier.
Referral to Clinical Genetics
- ●Primary care cannot deliver carrier testing: Targeted DNA analysis for DMD gene mutations requires specialist laboratory and counselling resources. The GP's role is to make a prompt, clearly documented referral to the regional Clinical Genetics service.
- ●What the referral should include: The precise diagnosis (DMD), the relationship to the affected child (nephew, maternal side), the sister's confirmed carrier status, and the maternal uncle's history. If the family has a genetics reference number from the sister's testing, include it — this significantly accelerates the process.
- ●Urgency: Given that Chloe is actively planning a pregnancy, the referral should be marked as time-sensitive. Waiting times for genetics services can be considerable; communicating urgency at the point of referral — and offering to contact the team directly — is appropriate.
Contraception — Continue Until Carrier Status Is Known
- ●Advise continuation of Microgynon 30: Chloe should not stop her combined oral contraceptive pill until her carrier status has been confirmed by the genetics service. This is one of the most important and commonly missed management points in this type of case.
- ●Rationale: If she conceives before knowing her carrier status, the options for an unaffected pregnancy become more limited and emotionally complex (prenatal testing followed by potential termination, rather than the option of PGT-M (Preimplantation Genetic Testing for Monogenic Disorders) before conception). Delaying conception until testing is complete preserves the full range of reproductive options.
- ●Timing sensitivity: Emphasise that contraception decisions can be revisited once results are available — this is not an indefinite delay, and the genetics referral should be made promptly to minimise the wait.
Reproductive Options for Confirmed Carriers
If the genetics team confirms carrier status, the following options should be discussed — not decided in primary care, but introduced here so that Chloe is not left without a framework for hope:
- ●Pre-implantation Genetic Testing for Monogenic Disorders (PGT-M (Preimplantation Genetic Testing for Monogenic Disorders)): Embryos created via IVF are tested for the DMD mutation before transfer, allowing only unaffected embryos to be implanted. NHS-funded for serious single-gene conditions including DMD. This is the option that avoids any risk of carrying an affected pregnancy to term.
- ●Prenatal diagnosis: Natural conception, followed by chorionic villus sampling (CVS) at 11–14 weeks or amniocentesis at 15+ weeks. Results confirm whether the fetus is affected. Requires the couple to consider their position on termination in advance.
- ●Donor eggs: Using eggs from a non-carrier donor eliminates the inherited risk entirely; the child would not be genetically related to Chloe.
- ●Natural conception with accepted risk: Some couples, after full counselling, choose to conceive naturally. This is a valid autonomous choice that must be respected.
- ●Present these as options to explore with the genetics team, not decisions to be made today. The purpose at this stage is to ensure Chloe leaves knowing that carrier status does not mean she cannot have a healthy child.
Pre-Conceptual Care Optimisation
- ●Folic acid: Chloe is already taking 400 micrograms daily — the correct dose for a woman without additional risk factors (BMI > 30, previous pregnancy affected by neural tube defect, antiepileptic medication, or coeliac disease would indicate 5mg). Advise her to continue from now until at least 12 weeks of pregnancy.
- ●Asthma: Well-controlled asthma managed with salbutamol PRN poses no barrier to conception. Salbutamol is safe in pregnancy. Poorly controlled asthma in pregnancy is associated with adverse outcomes (preterm birth, low birth weight, pre-eclampsia) — confirm control is maintained and advise her to contact the practice if symptoms worsen during a future pregnancy.
- ●Alcohol: Current intake (approximately 4 units/week) is low, but NICE and the CMO advise that the safest approach in pregnancy is to avoid alcohol entirely. A sensitive discussion about reducing to zero once she is trying to conceive is appropriate.
- ●Cervical screening: Confirm this is up to date — Chloe has had a normal smear approximately one year ago, which is within the 3-year recall interval.
- ●Rubella immunity: Consider checking rubella immune status if not documented. Non-immune women should be vaccinated before conception (MMR is contraindicated in pregnancy).
- ●Haemoglobinopathy screening: Offer as part of pre-conceptual care, guided by Family Origin Questionnaire, per NICE guidance.
Safety-Netting and Follow-Up
- ●Agree a clear plan before she leaves: (1) Referral to Clinical Genetics — prompt, marked time-sensitive; (2) continue Microgynon 30 until genetics results are available; (3) follow-up GP appointment after the genetics consultation to plan next steps.
- ●Offer an earlier review if her anxiety escalates, or if she has questions after receiving her genetics appointment letter.
- ●Signpost to support: Duchenne UK and Muscular Dystrophy UK provide information and peer support for families affected by DMD. Genetic Alliance UK supports families navigating genetic testing. Offering these resources acknowledges the emotional dimension and provides practical help between now and the genetics appointment.
- ●Psychological support: If the situational anxiety becomes persistent or starts to significantly affect her functioning (she is already tearful at work), discussing a referral for counselling or psychological support is appropriate — this does not require a formal mental health diagnosis.
Common Candidate Mistakes in This Case
- ●Advising her to stop the pill now: One of the most consequential errors in this case. Allowing conception before carrier status is confirmed removes the option of PGT-M (Preimplantation Genetic Testing for Monogenic Disorders) and limits the couple to post-conception prenatal testing. The clear, evidence-based advice is to continue contraception until results are known.
- ●Failing to quantify the risk: Vague statements like 'there is a chance you might be a carrier' are inadequate. Chloe needs to hear that her risk is approximately 1 in 2 — this is both honest and, critically, also means there is a 1 in 2 chance she is not a carrier.
- ●Offering a GP blood test for carrier testing: GP labs cannot perform targeted DMD gene mutation analysis. Ordering a standard blood test in primary care creates false reassurance and delays appropriate specialist referral.
- ●Focusing only on genetics and missing pre-conceptual care: The marking scheme assesses both the genetic management and the broader pre-conceptual optimisation. Candidates who spend the entire consultation on genetics and fail to confirm folic acid dose, asthma safety, and lifestyle advice will miss marks.
- ●Failing to acknowledge the emotional burden: This consultation carries significant psychological weight. Candidates who conduct it as a purely academic exercise — without validating Chloe's fear, acknowledging the impact on her marriage and work, or offering support — will not pass Domain 3.
Mapped to the RCGP curriculum topic: Genetics.
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