Tag Archives: dna

Could Genetics Play a Role in Degrees of Addiction?

As a practicing hypochondriac it was of particular interest to me to learn about a research company in, of all places, Iceland, which is making what could be historic advances in medicine through the study of human genetics.

This company, deCODE genetics, is exploiting a most unusual data base: that of the total population of Iceland where excellent records have been kept since Norwegian and Celtic (Scottish and Irish) settlers arrived there about ten centuries ago. Today there are only slightly more than 300 000 Icelanders, of whom 94 percent are descended from the original settlers. For gene searchers this is, apparently, like a gift from heaven.

It is akin to having a vast private laboratory, enabling research on thousands of volunteers uniquely related in a manner which renders the search for genetic clues to future health problems. For example, more than 50,000 Icelanders, that is one-sixth of the population, participated in research into the disposition to smoking and, for smokers, the inherent risks of contracting diseases linked to nicotine.

Now deCODE is coming up with suggestions that, through the study of human genetic makeup, or our DNA, it can be predicted with accuracy that one will be predisposed to a particular kind of illness or even, as in the case of cigarette smoking, particular types of addiction.

The company’s scientists have established “a clear link between a single-letter variant of the human genome (SNP) and susceptibility to nicotine dependence.”

Such addiction can lead, for example, to lung cancer and peripheral arterial disease (PAD), a common and debilitating constriction of the arteries to the legs.

The odds of this happening to a given individual can be calculated using these genetic techniques.

The research, which also studied smokers in New Zealand, Austria, Sweden, Italy, the Netherlands and Spain, revealed that there is correspondence not only between genetic makeup and the likelihood of addiction but also to the approximate number of cigarettes an addict is likely to smoke daily.

DeCODE has also isolated key genes “contributing to major public health challenges from cardiovascular disease to cancer, genes that are providing us with drug targets rooted in the basic biology of disease”.

smoking cigarettesGiven the incidence in South Africa of dermatological problems such as the deadly cutaneous melanoma (CM) and basal cell carcinoma (BCC) it is interesting to learn that it is not only very fair skin, blue or green eyes, freckles, red hair and exposure to ultraviolet light (obviously prevalent in South Africa) that can expose one to CM and BCC.

Scientists at deCODE have discovered that “a novel, tightly-linked pair of single-letter variants” near a certain gene on chromosome 20 and another on chromosome 11 specifically increases our susceptibility to sunburn and hence to its dangers.

All this should be of enormous future use to the medical profession, although one suspects that our health minister, Manto Tshabalala-Msimang, would probably prefer some quackery or other for guidance rather than the research of serious Icelandic scientists.

Interestingly, the company offers a personal, on-line service for those wishing to explore their genome tree or whatever geneticists call these things. Just log on to www.decodeme.com – although I haven’t done this, so I cannot advise you what to expect.

By the way, this little cutting edge company is listed on the Nasdaq in New York and the stock quote is DCGN. This writer holds no shares.

Source: Stephen Mulholland, Dispatch Online