Genealogy is the new shopping. A national pastime that is fast becoming an obsession. Millions tuned in to the BBC series Who Do You Think You Are? in which celebs traced their family trees. In a deeply moving programme, Bill Oddie discovered he had a sister who died when she was just five days old.
And he found that his mum, who had been hospitalised with "schizophrenia", had probably been suffering from postnatal depression. But Oddie is an exception. According to recent surveys by Norwich Union Healthcare, most of us haven't a clue about our family health history and aren't bothered about finding out more. Of GPs surveyed, 88% said we need to know more about hereditary conditions that run in our families, and only 55% felt the information they do get is accurate. In a concurrent study of 1,042 adults across the UK, the majority (79%) said they didn't need to know about their family's health history, and a third admitted they wouldn't feel confident at all if asked to give a family history.
It seems odd that we often know more about our friends' health problems than our family's. At least half of all serious illnesses are inherited, while the other half are due to lifestyle and environmental factors. We are bombarded with information about modifying our lifestyle, but hear little about investigating the inherited diseases we may be prone to.
So how do you go about mapping out your family history? As a starting point, Professor Doug Easton, director of Cancer Research UK's genetic epidemiology unit, suggests finding out what relatives died of and at what age. "The common inherited diseases are breast, ovarian and bowel cancers, heart disease, diabetes and strokes," he says.
All common cancers can run in families, but knowing you're at increased risk only helps you if there is a reliable screening test and treatment. "It's still hard to know whether screening for prostate cancer is helpful," says Easton. "On the other hand, knowing that the skin cancer melanoma runs in your family would be useful to you because you could be particularly careful to stay out of the sun and could have regular dermatology checkups to spot any melanomas at an early stage."
To map out your family history, you need to know how many family members have been affected by a disease and at what age they were diagnosed: that way doctors can assess your risk. So if you have one first-degree relative (sibling or parent) who had breast cancer before the age of 40, or two close relatives at any age, you are considered to be at moderate risk. But if you have two close relatives who were younger than 50 when diagnosed, you are at high risk. Women at moderate risk are recommended to have mammo-graphy from the age of 40 and those at high risk are offered gene testing. Knowing that you carry one of the abnormal breast cancer genes (BRCA1 or 2) is a heavy burden. A BRCA1 carrier has a 70% chance of developing breast cancer by the age of 70 and a 40% chance of ovarian cancer; BRCA2 carriers are at slightly lower risk. But the knowledge allows you to make choices about how you live, whether you opt for surgery to remove your breasts and ovaries to lessen the risk and whether you have children. Men who carry the gene have an increased prostate cancer risk so they can be alerted to that and have regular tests.
North London GP Dr Tina Farid often asks patients about family history, but people don't always have the information they need. "If a woman comes in and is worried about her breasts, I would always ask whether there is a family history of breast cancer. But the information is often a bit woolly. Women usually know if their close relatives have had breast cancer. But the criteria for referring for screening depend on the age at which they developed cancer and women often don't know that," she says.
Despite the huge growth in screening programmes, a sudden and unexpected early death is often the first clue that a condition runs in a family. Inherited clotting abnormalities may only be uncovered after a family member dies unusually young of a blood clot (thrombosis). Close family members are then usually screened for the clotting disorder and they can be offered blood-thinning drugs to reduce their risk. In retrospect, it may become clear that there have been several unexplained deaths among the wider family over the past few generations.
Knowing your family history can bring extreme heartache and anxiety. It can be particularly stressful, for example, to discover that you are susceptible to Huntington's disease (HD), which causes involuntary movements, personality and memory change. "If you carry the abnormal gene that causes Huntington's disease, every child you have has a 50% risk of inheriting it. And if you have the faulty gene, you will inevitably get the disease, although no one can tell you when," says Diana King, regional care adviser of the Huntington's' Disease Association.
Most people who have HD in the family have some inkling about it but King reckons that the diagnosis comes as a surprise to about a third of the 2,500 clients with HD whom she deals with. For the past decade, there's been a test for HD so if you know it runs in the family, you can be diagnosed before you get any symptoms. There is no way of delaying the onset of symptoms or correcting the abnormal gene yet. But the test does mean that if you carry the gene but want to have children, you can opt for IVF treatment. The embryos can be tested and only those without the faulty gene can be implanted.
GPs are used to asking whether heart disease or cancer runs in the family but are less good at asking about mental health problems, according to Vicky Lawson, training manager for the Bipolar Organisation (previously Manic Depression Fellowship). Bipolar disease can cause extreme mood swings from the lows of severe depression to the highs of mania. Mild mania (hypomania) can feel great; elated mood, loads of energy, and lots of creative drive. But it can also be very damaging as mania makes it hard to focus, keep things in perspective, hang on to your temper and keep in touch with reality.
Sufferers tend to go to their GP when they are depressed and are often misdiagnosed and prescribed antidepressants. But as someone's mood swings back into mania, antidepressants can be dangerous and may increase the risk of suicide. The cardinal pointers to a diagnosis of bipolar disease are a family history of the condition, drug and alcohol abuse, and periods of elation. "We need to push GPs to ask depressed people whether there is a family history of mental health problems or alcohol and drug abuse which people often turn to when their moods are fluctuating," says Lawson.
The flip side of knowing more about your family history is that you may have to disclose the information to insurance companies. Most insurers insist on a medical before authorising life insurance or mortgage cover. They ask you and your GP to give details of any first-degree relative who has had heart disease, stroke, diabetes, cancer, multiple sclerosis, Alzheimer's disease or any other familial condition before the age of 65. Fudging the truth can jeopardise your cover, but for your own sanity, it's worth remembering that none of these conditions is inherited in a predictable way; you may inherit a tendency to any one of them, but lifestyle and luck play their part too.
Case study: Ann Cole, 55
"My mum died of bowel cancer when she was only 55. She had been to the doctor with bleeding, but was told it was haemorrhoids. She got more and more ill and lost lots of weight. By the time they opened her up, her bowel cancer was too extensive to do anything and she died soon after.
"I was 30 then. My GP never mentioned screening but I paid for a full health screening check at 40, 45 and 50 years old. At 50, my stool sample showed traces of blood. The consultant said he was 99% sure it wouldn't be cancer, but it was. I had an operation to remove a third of my colon and a 30-week course of chemotherapy. Less than a year later, I found a lump in my abdomen that was another tumour. I had more operations and chemo and now just have annual checkups.
"My kids are 31 and 32 and they have a colonoscopy (intrusive examination of the bowel) every five years. It's not a pleasant procedure, but, by having the test, they will hopefully be spared what I've been through. There's a lot of talk about cancer being due to lifestyle and obesity but I think the genetics is more important."
To map out your own family health tree, log on to www.norwichunion.com/healthtree
Get information about screening for bowel cancer at www.beatingbowelcancer.org
