A DNA test for lactose intolerance, near Cardiff
Find out whether your genes are the reason dairy disagrees with you. This test reads the two variants of the MCM6 gene that govern whether your body keeps producing lactase into adulthood. One blood sample gives you an answer that holds for life. Self-refer at our Penarth or Cowbridge clinics near Cardiff.
A genetic answer, once and for good.
What is included for £154
- ✓Blood draw at Penarth or Cowbridge, near Cardiff
- ✓DNA analysis of the MCM6 gene: the C13910T and G22018A variants
- ✓A clear result: predisposed to lactose intolerance, or not
- ✓Plain-English report explaining what your genotype means
- ✓An answer that never needs repeating, since your genes do not change
- ✓Report emailed to you, easy to share with a clinician or dietitian
The difference between guessing and knowing
Cutting out dairy and seeing if you feel better tells you something, but it is slow, easily confused with other gut problems, and never quite certain. A genetic test looks straight at the cause. If you carry the variants linked to lactose intolerance, that is a solid reason to manage your diet. If you do not, your symptoms are pointing somewhere else, and that is worth knowing too.
Looks at the cause, not the symptom
Bloating and cramps have many causes. This test reads the actual gene behind primary lactose intolerance, so a positive result is a real explanation.
One test, for life
Your DNA does not change, so unlike a symptom diary or a breath test you never need to repeat it. The answer holds whatever you eat.
A doctor if you want one
A genetic result is a starting point, not a diet plan. Book a private GP appointment and one of our doctors will help you act on it sensibly.
Worth testing if dairy disagrees with you
Around one to two in ten people in the UK have some degree of lactose intolerance, and many never get a clear answer.
This test covers primary lactose intolerance, the common genetic kind. It does not test for a milk allergy, which is a different immune reaction, nor for coeliac disease. If your symptoms are severe or you are losing weight, please see a doctor.
One gene, two variants
The MCM6 gene acts as a switch for the neighbouring lactase gene, deciding whether you keep digesting lactose after childhood. We read the two variants that control that switch. Tap to see them.
MCM6 gene 2
Your report explains which variants you carry and what that means for digesting lactose.
Difficult veins? We find them with ultrasound
This test uses a small blood sample. If you have fragile or hard-to-find veins and have had failed attempts before, our consultant radiologists can take it under real-time ultrasound. It is the only such service in South Wales, and patients travel to us from across Wales and the West for it.
Nobody had managed to take my blood in years without several attempts. Here it was done first time with the ultrasound. Such a relief.
Verified Google reviewFrom booking to answers, step by step
Book
Self-refer online or by phone. No GP letter needed, and no fasting or special preparation for this test.
Your appointment
A small blood sample, taking about 15 minutes. Tell us if you have difficult veins and we will use ultrasound.
Your report
Because this is a DNA test, results take around 7 days. Your report explains which variants you carry and what they mean, in plain English.
Act on it
Optional: book a private GP appointment to talk through your result and how to adjust your diet if you need to.
Genetic Lactose Intolerance test
All inclusive. A DNA answer you will never need to repeat.
- ✓Blood draw at Penarth or Cowbridge
- ✓DNA analysis of the MCM6 gene, both variants
- ✓Plain-English report explaining your result, emailed to you
- ✓Ultrasound-guided draw available for difficult veins
A £50 booking deposit secures your slot and comes off the total.
Common questions about the genetic test
How much is the Genetic Lactose Intolerance test?
£154 all inclusive. That covers the blood draw, the DNA analysis of both MCM6 variants, and a plain-English report emailed to you. A £50 deposit secures your appointment and comes off the total.
How is a genetic test different from other lactose tests?
A hydrogen breath test or an elimination diet measures how you react to lactose on the day, which can be affected by other gut issues, recent illness or what else you have eaten. This test reads the underlying gene instead, so it tells you about your built-in predisposition rather than a single day's reaction. Studies have found genetic testing agrees very closely with the breath test for primary lactose intolerance.
What exactly does it look at?
It reads two variants, C13910T and G22018A, in the MCM6 gene. MCM6 sits next to the lactase gene and acts as its switch. These variants determine whether that switch stays on into adulthood. Carrying them is linked to keeping lactase active (tolerance); not carrying them is linked to lactase declining after childhood, which is primary lactose intolerance.
Do I need to prepare, or fast?
No. Because this looks at your DNA rather than anything you have eaten, there is no fasting and no special preparation. You can eat and drink normally beforehand, and keep taking any medication as usual.
How long do results take?
Around 7 days. Genetic analysis takes longer than a routine blood test because of the laboratory process involved. Your report explains your result clearly when it is ready, and we email it to you.
Will I ever need to repeat it?
No. Your genes do not change through life, so a genetic result is a one-off. This is one of the main advantages over symptom-based testing, which only ever captures a snapshot.
Does a positive result mean I must avoid all dairy?
Not necessarily. Many people with the intolerance-linked genotype can still handle small amounts of lactose, and tolerance varies from person to person. A result tells you the likely cause; how strictly you need to adjust your diet is best worked out with a doctor or dietitian. Book a private GP appointment if you would like help with that.
Does this test for milk allergy or coeliac disease?
No. A milk allergy is an immune reaction to the proteins in milk, which is different from lactose intolerance and can be more serious. Coeliac disease is a reaction to gluten. This test looks only at the genetics of primary lactose intolerance. We offer separate tests for allergy and coeliac disease if those are a concern.
Do I need a GP referral?
No. This is a self-refer test. Book online or call 029 2199 9300.
Where is the blood taken?
At our Penarth clinic (13 Washington Buildings, CF64 2AD) or our Cowbridge clinic (10 High Street, CF71 7AG). Both are a short drive from Cardiff with easy parking.
Want help acting on the result?
Knowing your genotype is the start. Book a private GP appointment and one of our doctors will explain what it means for you and help you plan any changes to your diet, sensibly and without cutting out more than you need to.
Book a GP appointmentTwo clinics, close to Cardiff
Penarth Clinic
13 Washington Buildings
Stanwell Road, Penarth
CF64 2AD
Mon to Thu 9:00 to 18:00
Fri 9:00 to 17:00
Sat 9:00 to 15:00
Cowbridge Clinic
Beauty Within
10 High Street, Cowbridge
CF71 7AG
By appointment. Please call for availability.
Get directionsPatients travel to us from Cardiff, Penarth, Cowbridge, Barry, Newport, Bridgend and across the Vale of Glamorgan.
Important: This test identifies a genetic predisposition to primary lactose intolerance and does not diagnose it on its own, nor does it test for milk allergy, coeliac disease or secondary causes of dairy intolerance. A genetic result is most useful when interpreted by a doctor alongside your symptoms, so we recommend discussing it with your own GP or booking a private GP appointment with us before making major changes to your diet. Lab values alone do not constitute medical advice.
Stop guessing about dairy.
Self-refer for the Genetic Lactose Intolerance test: a DNA read of the MCM6 gene that gives you a lifelong answer. £154 all inclusive at Penarth or Cowbridge, near Cardiff.