Before You Go For Genetic Testing, Read This

With Consultant Clinical Geneticist, Dr Fiona Lalloo

Lizzie: Fiona, you’re actually the first Consultant Clinical Geneticist I’ve had on the podcast — which feels long overdue! Could you begin by explaining your role in the MEN1 diagnosis process?

Fiona: We typically get involved in two ways. One is when we’re asked to give an opinion on a patient who’s showing clinical features suggestive of MEN1. We’ll review their records, examine the symptoms, and if we believe the diagnosis is likely, we organise genetic testing. The second scenario is familial: if a known MEN1 mutation exists in a family, we can test unaffected relatives to determine their risk and ensure they’re enrolled in screening if necessary.

Lizzie: What if someone suspects they have MEN1 but doesn’t have a known family mutation?

Fiona: They should start with their GP. If the GP notices endocrine abnormalities, they’ll refer them to an endocrinologist, who might then refer them to us for genetic testing — especially if a clinical picture consistent with MEN1 emerges. Sometimes endocrinologists will even handle the initial testing and refer to us afterwards.

Lizzie: That’s helpful context. I’ve heard from patients that it can be incredibly hard even to get to the endocrinologist stage. The process often feels long, slow, and frustrating.

Fiona: Yes, the initial diagnosis is difficult because many features of MEN1 — like pituitary lesions or high calcium — are relatively common in the general population. MEN1 itself, though, is rare, so unless someone has a combination of features, it might not be considered early on.

Lizzie: I’ve spoken to many listeners who feel this exact frustration. I wanted to ask you about genetic counselling — something I didn’t really go through myself. What exactly does it involve?

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Fiona: Genetic counselling is different from therapeutic counselling. Its aim is to inform and support someone through a genetic diagnosis. If someone’s struggling, we help them understand the condition and its implications — not just for them, but for their family. For children, we start with basic conversations around screening and return later, in their late teens, for more in-depth discussions about inheritance and family planning.

Lizzie: That’s a really important distinction. I’d always conflated the two types of counselling. I also wanted to ask about family planning — how does that process look for MEN1 patients?

Fiona: It depends on the age at diagnosis. For children, we talk in simple terms and focus on keeping them well. By their late teens or early twenties, we explain inheritance, options for reproduction, and the potential risks to future children. When they’re in relationships, we might meet with the couple to discuss testing, prenatal options, or IVF with preimplantation genetic diagnosis. That’s where a genetic counsellor becomes crucial.

Lizzie: That brings us to a huge topic: uncertainty. People often hope that getting genetic test results will give them certainty — but it doesn’t always work that way.

Fiona: Precisely. I can tell you whether you have the MEN1 mutation. But I can’t tell you exactly what symptoms you’ll develop or when. That’s the nature of this condition — it’s highly variable, even within families. We can talk about probabilities, but not certainties. And that uncertainty can be very hard to manage, especially for patients with health anxiety. In those cases, we sometimes refer to psychological support.

Lizzie: Anxiety is such a big theme in my community. I’ve also had many people ask whether it’s worth going privately for testing — especially if NHS waiting lists are long. What are your thoughts?

Fiona: If it’s predictive testing — meaning a mutation is already known in the family — I recommend sticking with the NHS. You’ll get the support of a full genetic service, which you often don’t receive if you go private. Even for diagnostic testing, you need to be careful. Many private companies use large gene panels and might find mutations that are irrelevant but still cause stress or require further investigation. You might end up with more information than you bargained for.

Lizzie: That’s such an important point. I had no idea that private gene panels could reveal totally unrelated mutations — and potentially cause problems that wouldn’t have otherwise existed.

Fiona: Exactly. Plus, the NHS genetic system is very well set up. It’s collaborative. If I’ve seen your father in Manchester and you turn up in a clinic in Exeter, we can quickly coordinate. That’s much harder in the private system.

Lizzie: I know some of our US listeners will be wondering how this translates to their healthcare setting. What would your advice be to them?

Fiona: In the US, any physician can order a genetic test, but you might not get to speak with a genetic counsellor unless you request one. I’d recommend doing that. Also, the approach is different — there’s more of a rush to test and less emphasis on pre-test counselling. Offers like “half-price for relatives” are not uncommon, but they bypass important discussions about consent and implications. It’s a very different mindset.

Lizzie: You’ve helped me understand so much already. Before we finish, I wanted to ask whether epigenetics plays any role in MEN1?

Fiona: It’s possible, especially in explaining why symptoms vary, but I’m not familiar with the specific literature. We know that mutations happen at conception — every person carries some. In the case of MEN1, it’s a clear Mendelian inheritance: dominant, autosomal, and high penetrance. But variability still exists, and we don’t fully understand why.

Lizzie: Fiona, thank you so much. You’ve offered so many insights — from the value of NHS genetics to the complexity of navigating an uncertain diagnosis. I’m incredibly grateful for your time and I know our listeners will be too.

Dr Fiona Lalloo is a consultant in Cancer Genetics. She qualified from Newcastle University in 1990 and trained in adult medicine before moving into Genetics in 1994. Her MD was undertaken on the genetics of breast and ovarian cancer. She was appointed consultant in 2001. She has been involved at a national level with the recruitment of trainees into clinical genetics and is currently Chair of the Cancer Genetics Group. Dr Lalloo is involved with teaching of both undergraduates and postgraduate medicine devising, instigating and running the first national course on cancer genetics. She has maintained her research interest in breast and ovarian cancer and is the author of “Genetics for Oncologists”. Her clinical interests include breast, ovarian and bowel cancer and endocrine malignancies. She is currently Clinical Lead for Genetic Medicine.

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Disclaimer: This interview is intended for informational and educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before making personal medical decisions.