HOW DO your genes affect your health? You probably don't really know right now, but that will soon change, writes CLAIRE O'CONNELL.
As the cost of technology falls and as we understand more about how variations in our DNA “letters” contribute to the risk of disease, you can bet genetic sequences will be part of our medical future.
And one expert, who will talk in an upcoming lecture series in Dublin, believes patients and doctors alike need to be informed and ready for that revolution.
“We have made really rapid progress in understanding how variation in our genomes [DNA] is contributing to our health,” says Dr Gianpiero Cavalleri, a biomedical research lecturer at the Royal College of Surgeons in Ireland (RCSI).
“People need to empower themselves with the basic knowledge that’s required to interpret the results from these studies. And physicians need to be trained to understand what this information means and how it can be passed on to patients.”
The devil lies in the detail – the tiny differences in our genetic make-up that can combine to influence how our individual bodies work, he explains.
“If you take two people, sequence their entire genomes and line them up together, you see around three million positions that are mismatched. And it’s those variations that contribute to at least a proportion of the differences in traits we can measure, like height or weight or the types of diseases you are at risk of developing.”
As part of the RCSI’s Mini Med School series of public lectures, Cavalleri will explain the techniques scientists use to link gene variations with particular traits. The technology has improved in recent years, meaning researchers can now screen enormous numbers of patients for genetic data and find strong associations between carrying particular versions of genes and the risk of developing a medical condition, he explains.
“They are starting to move on to the question of heart disease with really big numbers – there are studies coming out of around 22,000 people and these have all had a genome scan, so there’s major funding behind it.”
But while individuals can order genetic screens for under €300 from private companies like US-based 23andme, they won’t get much relevant medical information from the results yet, according to Cavalleri.
“The actual value that comes from that test is modest at the moment,” he says. “But this technology is here, it’s not going to go away, and the value that an individual can garner from this information will increase in the near future as the academic studies start to discover more risk variants and understand how they interact with the environment and with each other.”
In the meantime, he notes that a healthy lifestyle is the best way to beat the genetic odds in many cases. “You might carry a variant that gives you an odds ratio of two of developing heart disease, so it’s twice as likely. And people think this is terrible, there’s nothing I can do, I have this genetic variant and they almost accept the risk. Whereas in reality if you eat well, you probably reduce the risk by even more. The genetics might explain it, but you can do something about it.”
And if, despite your efforts, you wind up in hospital, you may encounter infectious bugs like MRSA and C difficile. Hospital infections have been around as long as hospitals, but they have appeared on the public’s radar only in recent years, notes Hilary Humphreys, professor of clinical microbiology at RCSI, who will address the Mini Med School in March about hospital-acquired infections.
Pressure from patients and the public has raised the profile of the bugs, he says. “Patients are consumers and like any consumers you apply a critical approach to a service when you think that service isn’t meeting your expectations. And I think that’s a big issue as to why it has emerged as a political and public health issue, even though many professionals have been concerned about this area for some time.”
Prof Humphreys, a consultant microbiologist at Beaumont Hospital, cites recent figures that 5-10 per cent of patients admitted to an acute hospital develop a hospital-associated infection.
The majority are caused by “bog-standard” microbes, he says, but there are also cases of antibiotic-resistant bacteria like MRSA and C difficile.
Bacteria can adapt rapidly to their environment, and medical advances like transplants and chemotherapy that weaken the immune system, as well as Ireland’s hospitals often having old-fashioned designs, means that ambient microbes can cause trouble for vulnerable patients, explains Humphreys.
And as the winter vomiting virus currently rips through hospital wards, he advises patients and visitors alike to take care with hygiene.
“Some of the winter vomiting bug comes in from the community and then if someone has it in hospital they may give it to a visitor who brings it back out, so it’s like a revolving door,” he says, suggesting that visitors stay at home or at least curb their enthusiasm.
“Try to avoid going from one patient to another. If you do, wash your hands adequately, but it’s probably preferable to visit one patient and then leave.”
Mini Med hour-long lectures
How can you really cut your risk of heart disease? What conditions can we diagnose in unborn children? And what kind of impact can snoring have on your life?
If you want to find out more about these and a range of other health-related questions on psychiatric illness, anatomy, diabetes, childhood accidents, cancer and general practice, then keep your Tuesday evenings free.
From today until March 24th, the Royal College of Surgeons will run a series of 18 Mini Med School hour-long lectures, two each Tuesday evening (except for St Patrick’s Day), and a hands-on clinical measurements workshop, to give attendees an insight into medical practice and topical issues.
Tonight consultant obstetrician Prof Fergal Malone and gerontologist Dr Riona Mulcahy will talk about the diseases of the very young and the very old.
- Registration for the course costs €150 and you can sign up until the lectures start this evening at 7pm at the Royal College of Surgeons in Ireland, 123 St Stephen's Green, Dublin 2. For more details or to register visit www.minimedschool.ie or call (01) 402 8662.