Research success highlights importance of twin studies

February 08, 2007

Professor Brian Byrne, a principal researcher in an international project that is revealing the importance of genetic factors in children's reading ability, says the role of twin studies in medical and psychological research is becoming increasingly important.

Professor Byrne, from the School of Psychology at the University of New England, has been invited to join the new Expert Reference Group of the Australian Twin Registry (ATR). He said the Group, which would provide scientific advice to the ATR, was being established with the help of a National Health and Medical Research Council Enabling Grant.

More than 30,000 pairs of twins are currently enrolled with the ATR, which aims to enable studies of the impact of genetic and environmental factors on health, and on the treatment and prevention of disease. Professor Byrne's project (funded by the Australian research Council, the US National Institutes of Health, and the Norwegian and Swedish Research Councils) has so far involved about 250 sets of twins in Australia, and 750 in the United States, Sweden and Norway.

Professor Byrne said that the development in the 1970s and 1980s of powerful new mathematical and statistical techniques for analysing data, alongside advances in molecular biology, had enabled the current focus on the value and potential of twin studies. He said such studies were being used in a wide range of medical and psychological fields, including research on cancer, skin, bone, and eye diseases, mental illness, and personality problems.

His own research team at UNE – in collaboration with their colleagues in Sweden, Norway, and the US State of Colorado – are producing useful (and often surprising) results. In following children through the pre-school and early school years, they have found, overall, that the environmental influences of home and school become less significant as children progress from pre-school to Year 2, and genetic influences become more dominant. "We're finding substantial genetic effects on children's reading and spelling in their early school years," Professor Byrne said, "and we're not finding big effects of different schools – or even different teachers – on the literacy levels of children within the same school year."

Using DNA samples, the researchers can potentially identify specific genes involved in reading ability.

Professor Byrne explained that the principle of twin studies central to distinguishing between genetic and environmental influences on behaviour and proneness to disease was a comparison of identical twins (who share an identical genetic make-up) with fraternal twins (who share only half their genetic make-up). "Identical twins will be more similar to each other than are fraternal twins in cases where genetic variability has more influence on behavioural variability," he said. "Where the family environment is of more importance, both twin types will be equally similar."

He urged twins and parents of twins to consider registering with the ATR, and contributing to the ATR's efforts "to help make a difference to health and wellbeing". He pointed out that participation in any research project was entirely voluntary, and that the registry was open to any "multiples" – triplets, quads, etc. (His own project has involved several sets of triplets.) The contact number for the ATR is 1800 037 021, and the organisation's Web site is http://www.twins.org.au.

Posted by Jim Scanlan at February 8, 2007 05:41 PM