HCF Fit and Well : HCF Fit and Well Summer 2015-16
CAN TELL YOU WHAT YOUR DNA The more we know about the links between DNA and disease, the earlier we can catch and treat some conditions. W atch any sci-f flm involving genetics (think Jurassic Park, X-Men, Blade Runner) and the technology is often used to resurrect extinct animals or create superhumans. In reality though, since scientists fnished mapping the human genome in 2003 they have been striving to learn more about the links between genes and disease. As a result, according to the Australian Medical Association, in the future genetic testing will increasingly play a vital role in helping to prevent, diagnose and treat illness. The role of DNA Your body is made up of trillions of cells and inside each one is a core (or nucleus) that houses your chromosomes. These strands of DNA (deoxyribonucleic acid) look a little like twisted ladders. Segments of those ladders contain your genes. “Genes are the instructions for your health and for how your body grows and develops,” says Associate Professor Kristine Barlow Stewart, medical and 8 FIT&WELL scientifc board adviser for the Genetic Alliance Australia (GAA). “An estimated 200,000 to 250,000 genes serve as blueprints for all your DNA.” Just as you inherit genes for such characteristics as hair colour and height from your parents, you can also inherit genes that predispose you to certain health conditions. Sometimes those genes contain a variation (a little like a spelling mistake in an email chain) that disrupts the gene’s coded message. “These mutations can occur spontaneously with no known cause or can be inherited,” Dr Barlow Stewart explains. Causes of genetic conditions According to the GAA, there are four main types of genetic conditions. • Single gene conditions Scientists currently estimate that over 10,000 human diseases are caused by a single error in a single gene in human DNA. These cause conditions such as haemophilia and cystic fbrosis. • Chromosome conditions Over 1,000 known conditions are caused by chromosome abnormalities. “These abnormalities cause either a change in the structure or the number of chromosomes,” says Dr Barlow Stewart. They include conditions such as Down syndrome. • Mitochondrial conditions The mitochondria are the powerhouse of the body’s cells. “These kinds of genetic conditions are caused either by inherited or spontaneous alteration in the mitochondrial DNA,” she says. This can lead to cardiac disease, liver disease, diabetes, respiratory complications, seizures, visual and hearing problems and other complications. • Multifactorial conditions “Common medical problems such as diabetes and obesity do not have a single genetic cause – they are likely associated with the effects of multiple genes in combination with lifestyle and environment factors,” says Dr Barlow Stewart.
HCF Fit and Well Winter 2015
HCF Health Agenda - Issue 01