Understanding genes is vital

Four times a year at Timaru Hospital, families with genetic disorders discuss in detail their personal and family histories to learn more about the conditions they may carry.

People not showing any symptoms may be unaware they are a carrier of an inherited disease and can pass it on to their children.

So far, about 13,000 genetic conditions have been identified, and this number grows daily as more genes are identified.

Genetic Health Service New Zealand, part of the public health system, has hubs at Christchurch, Wellington and Auckland Hospitals.

The service meets people with genetic conditions or those who could be at risk of them, who have been referred by their doctor or specialist. Outreach clinics from each hub are held throughout New Zealand, including Timaru, where about eight to 10 patients are seen each session.

Senior genetic associate Dr Caroline Lintott said mutations causing inherited diseases could result from a chance event during conception from the sperm or egg sperm cell, or could be inherited from a parent.

"Each of us has around 22,000 genes encoded in our DNA," she said.

After assessment, DNA may be extracted from blood and can be analysed or stored. Laboratories in New Zealand or overseas try to identify mutations or variants in the gene sequence.

The results can help individuals or their families to understand their condition, and who in their family might be at risk. Dr Lintott said 70 per cent of her caseload were families with possible inherited cancer syndromes. The most common is familial breast and ovarian cancer syndrome caused by mutations in two genes called BRCA1 and BRCA2.

Detecting genetic conditions and those at risk enables optimum medical care, potentially saving lives and contributing to better understanding of inherited diseases, she said.

The Timaru Herald