Scientists reveal dangers of Western world’s most common genetic disorder

The Western world's most common genetic disorder causes far higher levels of serious disease and disability than previously thought, despite being easy to detect and treat, research has shown.

Two major studies have revealed that the iron overload condition haemochromatosis, previously thought to be a low-level health risk, actually quadruples the risk of liver disease and doubles the risk of arthritis and frailty in older age groups.

It also causes higher risk of diabetes and chronic pain.

The studies in UK Biobank data found that the number of deaths from liver cancer in men with the faulty genes was significantly higher than expected, although the number of deaths was small.

The research, led by the universities of Exeter and Connecticut, suggests that routine screening may be needed for people at risk of haemochromatosis.

Haemochromatosis causes people to absorb too much iron from their diet, which accumulates around the body over time, damaging organs and eventually causing disease.

It is the most common genetic disorder in the UK. An estimated 250,000 people of European ancestry in the country have the disease, which is caused when people have two particular faulty genes.

Who carries the gene?

One in eight people in some areas of the UK are carriers, meaning they have one of the two faulty genes. If both parents are carriers then two faulty genes can be passed on to their children.

Symptoms can include feeling tired all the time, muscle weakness and joint pain, meaning it is often misdiagnosed as the signs of ageing.

  • Feeling tired all the time
  • muscle weakness
  • joint pain
The researchers found that in men, 1.6% of hip replacements and 5.8% of liver cancers occurred in those with the two gene mutations.

Professor David Melzer, who led the research, said: "The haemochromatosis mutations were thought to only rarely cause health problems. We've shown that hereditary haemochromatosis is actually a much more common and stealth disease, including in older people.

"We now need to test ways of screening and diagnosing haemochromatosis earlier. It's exciting to think that better care might prevent so much unnecessary disease."

The team analysed data from 2,890 people with the two genetic mutations. Of that group, one in five men and one in 10 women with the mutations developed additional diseases, compared with those without mutations.

Celtic curse

Genetic haemochromatosis is thought to have evolved when past populations moved to places where meat was scarce.

In Ireland, it is known as the "Celtic curse", although it is common throughout northern Europe and also occurs at a lower level in southern Europe and is common in Australia and the US.

The condition is twice as likely to be serious in men, and women have partial protection until later in life because they lose iron through menstruation and having children.

Treatment initially involves the regular removal of blood, known as a venesection, and this is usually carried out every few weeks.

Dr Luke Pilling, a member of the research team, said: "We found that diagnosis of haemochromatosis is often delayed or missed. That's not surprising as symptoms such as joint pains and tiredness are frequently mistaken as signs of ageing.

"Yet it is likely that these potentially deadly health risks could be treated and avoided, transforming lives, especially at older ages."

The two papers are:

– Common conditions associated with Hereditary Haemochromatosis genetic variants: cohort study in UK Biobank, published in The BMJ

– Hereditary Hemochromatosis Associations with Frailty, Sarcopenia and Chronic Pain: Evidence from 200,975 Older UK Biobank Participants, published in the Journal of Gerontology: Medical Sciences.

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