Mention iron overload in conversation and you're likely to receive a few blank stares. While most of us are familiar with the symptoms of iron deficiency, few know about its counterpart, haemochromatosis.
This is a hereditary condition in which excessive amounts of iron are absorbed from the diet and stored in a variety of organs, including the liver, heart and pancreas, and also in the joints.
Because it is more common in Ireland than anywhere else in the world, it's sometimes known as the Celtic Mutation.
The most common indication of haemochromatosis is chronic fatigue. Additional complaints depend on the areas that have been most affected by the condition.
Diagnosis is by way of a few simple blood tests, while treatment involves having blood taken at specified intervals.
Approximately 1pc of the Irish population have haemochromatosis, according to Barry Kelleher, consultant gastroenterologist at the Mater Hospital. "If diagnosed early, the prognosis in the vast majority of cases is very good, provided regular blood depletions are carried out to offset the iron overload," he says.
"However, when detected late in life, damage caused over the years can, for a minority, be life-threatening. Why some experience a far more aggressive form of the disorder than most is not yet known.
"As iron builds up slowly in the body, the typical male, if left unscreened, will be in his early 40s before realising that all is not well.
"Women, on the other hand, offload some of the excess iron during menstruation, and so are usually in their early 50s before experiencing signs of the disorder."
Dr David Sowby was aged 75 when he discovered that he had the condition, six years ago.
"The realisation came about as a result of hearing Margaret Mullett, chairperson of the Irish Haemochromatosis Association, speaking on a radio programme about how she had so tragically lost her husband George, a 63-year-old consultant psychiatrist, to the condition," he says.
"Her words touched a chord so I had some tests, which showed that I had the disorder.
"Because it went undetected for so long, my pancreas and liver were damaged, causing diabetes and cirrhosis. I
subsequently developed two cancerous tumours on my liver, which have since been successfully removed."
Many of those suffering from exhaustion as a result of iron overload unwittingly take iron supplements and tonics high in iron, as a method of fending off fatigue.
A former chemistry teacher, Margaret laughs as she recalls how she was affectionately known to her students as Iron Maggie.
"It's ironic, given my nickname, that raising awareness of the dangers of iron overload has since become a great passion of mine," she says.