Tata Memorial head calls scans futile

MUMBAI: Though the medical fraternity in India is largely unaware about the genome scans that were introduced here last month, Sandeep Saxena of Pune-based Acton Biotech says they have already done 20 genome scansand inquiries are coming in.
Bangalore-based Avesthagen Limited's Naveen Sharma said the personalized genome scans, that might help predict predisposition to some diseases, are a "bottomless gold mine".
Genetic testing isn't a new concept. Immense research is being carried out on in this field, but mainly in the West. From genetic tests that help quicker diagnosis of drug-resistant tuberculosis bacilli to gene tests to establish paternity, the Indian marketplace too is waking up to this nascent field's potential.
The new factor here is that instead of a single gene relating to a single disease or condition, people can get their entire genome scan. "Genes play a big role in a person's chance of getting a disease. Many smoke but not all get lung cancer. The genome scan can tell you whether you are at risk for cancer. It can tell if you are prone to hearing loss or obesity," said Saxena. The idea is that one can take preventive steps such as limiting the use of headphones or avoiding a sedentary lifestyle based on the forecast.
On paper, these scans can reveal people's predisposition for over 200 diseases-ranging from diabetes, asthma, hypertension, arthritis, obesity, baldness and cancers, among many others. "Basically, our scan will state the relative risk for a disease. So, if the person has a genetic make-up that predisposes him/her to cardiac problems, we will state the percentage of risk," said Saxena.
Avesthagen's Sharma is candid: "At present, genome scans are based on data derived from the Caucasian population that has not yet been validated on the Indian population. We are working with a chain of hospitals on validating this." So, while the Avesthagen scan at present only offers to tell all about two diseases, their list will expand to include 40 diseases within the next six months.
Tata Memorial Hospital director Dr Rajan Badwe calls these scans futile. "There is no scientific evidence to offer these tests to the public. What is the point of knowing the risk if there is no cure?" Dr Badwe believes it is an excellent research tool, but there is no point running them for all.
Another doctor who doesn't want to be identified said: "If the results say you have 60% relative chance of getting a heart attack, what does it mean in actual terms? There is no place for this in today's medicine."
In an article written in New England Medical Journal's January 2008 edition, Harvard Public Health School experts pointed to shortcomings. "Most of the diseases listed by the direct-to-consumer testing companies (eg, diabetes, various cancers, and heart disease) are so-called complex diseases thought to be caused by multiple gene variants, interactions among these variants, and interactions between variants and environmental factors," it said. In other words, the relative risk factors make it difficult to distinguish people who will develop these diseases from those who will not.