Predictive gene testing for Huntington disease and other neurodegenerative disorders.

Background: Controversies exist around predictive testing (PT) programmes in neurodegenerative disorders.

Aims: This study sets out to answer the following questions relating to Huntington disease (HD) and other neurodegenerative disorders: differences between these patients in their PT journeys, why and when individuals withdraw from PT, and decision-making processes regarding reproductive genetic testing.

Methods: A case series analysis of patients having PT from the multidisciplinary Western Australian centre for PT over the past 20 years was performed using internationally recognised guidelines for predictive gene testing in neurodegenerative disorders.

Predictive and pre-natal testing for Huntington Disease in Australia: results and challenges encountered during a 10-year period (1994-2003).

This study summarizes 10-years' experience of predictive and pre-natal testing and pre-implantation genetic diagnosis (PGD) for Huntington disease (HD) in Australia. Results are presented from 2036 direct mutation predictive tests conducted between January 1994 and December 2003. Thirty-eight per cent of results (776/2036) were positive, 56% (1140/2036) were negative, and 6% (120/2036)) were in the mutable normal (27-35 CAG repeats) or in the reduced penetrance (36-39 CAG repeats) ranges.

Genetic testing for Alzheimer's disease.

Genetic factors are important in the development of Alzheimer's disease (AD). Familial AD can result from rare mutations in some genes. Other genes, such as the apolipoprotein E gene (APOE), operate as risk factors for late-onset sporadic AD.