Always a trend-setter, I’ve been living in my own personal vampire movie for the past eight months.

Every Monday, and sometimes on Thursdays too, I have nearly a pint of blood drained from my body.

My “vampires” are benign, pleasant in fact, they work daylight hours in the NHS and without them I’d be in serious trouble.

I have, it’s been discovered, a fairly common genetic disorder called haemochromatosis, a long word meaning I have too much iron in my blood.

An iron overload caused by Genetic Haemochromatosis (GH) can cause liver disease, diabetes, weaken the heart, leave you impotent and depressed and give you arthritic pain in your bones. So, you can understand the incentive I have to seek out these friendly vampires, the nurses who bleed me regularly until the amount of iron in my blood reaches normal levels. It’s an old-fashioned treatment for a genetic disorder that’s not widely known but might affect as many as one in 200 Scots. Read on, you might be in the wrong movie too.

GH can’t be cured but taking the iron out with the blood reduces the risk of more serious illness. So far with me it’s been about three gallons of blood down the drain, enough to keep the Twilight film franchise going for another few seasons. I’m just about halfway through my treatment and physically, well, it’s tiring. But before I get into that let me start my vampire tale at the beginning.

As usual, I blame my brother. I felt perfectly fine until he started complaining of abdominal pains and listlessness. I made the elder brother diagnosis – he was obviously suffering from sloth. Fortunately, for us both, he had a second opinion and blood tests showed excessive levels of iron. One gene test later and he was diagnosed with haemochromatosis. “What-o, what-o, what?” I asked on the phone. If he had it, then it was quite likely his siblings did too.

My GP was endearingly honest: she hadn’t heard of GH either but soon we were both up to about the same level of Wiki-expertise. I was swiftly referred to a consultant haematologist who took one look at my stratospheric iron levels and started the bloodletting without waiting for a gene test.

The average level of iron in the blood, measured by the amount of ferretin, the protein that binds to iron in the blood, can vary between 50 and 300 depending on the individual. My brother come in at an impressive 1000ft. I weighed in with more rivets than the Forth Road Bridge – 2500ft. With treatment my brother’s levels have dropped right down. I’ve proved more resistant, replacing the

iron as quickly as they can drain it away, hence the sometimes twice weekly venesection.

As the consultant started explaining the effects of GH quite a few things began to make sense. For some months I’d been waking in the night with a worrying “pins and needles” sensation in my arms. One knuckle was permanently sore and swollen and I had occasional shooting pains in my wrist.

The iron accumulated in the body has to go somewhere, the consultant explained. The liver, the body’s blood filter, deals with most of it but excess amounts can crystalise in the joints causing pain, usually in the knuckles,

and can cause carpal

tunnel syndrome, pressing on nerves in the wrist. Immediate X-rays showed no sign of arthritis and the pain has all but disappeared in the months since I started treatment.

A word here about my treatment. It has been quite unbelievable. Every Monday I walk back down the Mile End Road shaking my head in bewilderment at the professionalism of it. All these tests, all the expertise and the care with which it is administered – it’s all free.

My brother, in rural Scotland, enjoys a walk-in, personal venesection service. In London, I book my treatments at the local hospital and wait with people

who are genuinely ill with other blood disorders and whose discomfort knocks my inconvenience into a pint pot of plasma fluid.

The tests have been mostly fun – glucose absorption for diabetes, barium meal (OK, not that much fun) and a ridiculously intimate encounter with a sonographer, who wrapped herself around me as she applied an ultrasound to my chest. “Your heartbeat is slow,” she said in our strange embrace. “I think it’s about to speed up,” I giggled, as I opened my heart to a stranger.

An excess of iron also causes bronzing of the skin, which I found a bit of a personal blow. There’s a theory that some of us Hebrideans are descendants of shipwrecked sailors from the scattered Spanish Armada. I’ve always enjoyed being mistaken for a stray Iberian, but my GH gene blows that myth out of the water. However, it does raise the intriguing possibility that the Armada story is a 16th-century Gaelic explanation for a defective gene condition that is apparently prevalent across the Celtic nations of the UK.

One theory is that the gene emerged

as a method of absorbing high amounts of iron from a meagre diet in times of famine, common enough in rural Scotland and Ireland centuries ago. It’s been called the Celtic Curse but that’s something of a misnomer because it’s really a Scandinavian Scunner and far more of our Nordic cousins suffer.

Women, because they menstruate and lose iron that way, develop the condition later in life. My sister, for example, has the gene but is only slightly anaemic. Diet does little for it: the amount of iron in a pint of Guinness or a rare steak is minuscule compared to my internal Ravenscraig absorbing the iron from what I eat.

GH is surprisingly common. In Scotland it is estimated about 25,000 people are affected with the condition, having inherited two copies of the mutated C282Y gene, and 600,000

carry one copy of the mutated gene. That’s about one in 200 people who could be affected.

While I make light of my early diagnosis, untreated it can be a killer. In fact, people like George Scott, who heads the Haemochromatosis Society, think it is the unrecognised factor in Scotland’s bad health story. Tomorrow, Mr Scott is due to present a petition to the Scottish Parliament calling for routine screening for the rogue gene which is easily affordable and could save lives.

That makes perfect sense. Late onset diabetes, cirrhosis, liver cancer, pancreatic cancer, loss of libido and fatigue are all part of Scotland’s basketcase of bad health statistics. Many people could be suffering from these conditions because they have a gene that leaves too much iron in their blood.

Remember, it starts with waking in the middle of the night with a tingling feeling in your arms. Next, the tell-tale puncture marks and then you find yourself walking around in a tired, half-sleep letting people drain blood from you. Haemochromatosis – just your typical vampire movie, really.

Haemochromatosis: the facts

What is it?

Haemochromatosis is a genetic iron overload disorder. Iron accumulates from the early 20s onwards. Excess iron is deposited in the liver, pancreas, other glands and the heart. Untreated, it results in irreparable organ damage, including cirrhosis, diabetes or cardiomyopathy.

What are the symptoms?

Chronic fatigue, weakness, lethargy, abdominal pain, arthritis, diabetes (late onset type), liver disorders, sexual disorders, disease of the heart muscle, neurological/psychiatric disorders and skin bronzing.

How is it inherited?

If both parents have GH or are carriers of the mutant gene, then the chances are all or some of the children will also be carriers or develop the condition. Relatives who are at risk should be tested from the age of 18.

Can it be treated?

There is strong evidence that early treatment, normally by venesection, preserves normal life expectancy.