05-02-2008, 03:09
DNA testing for mutations in genes causing neurogenetic disorders is becoming a common practice in clinical neurology. The tests are highly sensitive and specific. They are especially valuable in establishing diagnoses in symptomatic patients. These DNA tests are also used in asymptomatic persons at risk for genetic diseases who wish to determine whether or not they have inherited an abnormal gene. There are risks and benefits to such asymptomatic, predictive testing. A number of complex issues need to be considered including precipitation of depression, prenatal diagnosis and testing of children, impact on insurance and employment, legal aspects, possible third-party coercion, and an understanding of each test's limitations. Therefore, these DNA tests need to be used with careful clinical judgment and in the context of each individual patient and family.
Introduction
The past decade has witnessed a new development in the practice of neurology. Genetic research and technology have provided the knowledge and tools for the development of highly sensitive and specific DNA tests for neurogenetic disorders.[1] These tests directly identify mutations in disease causing genes. The number of diseases available for such testing is expanding at a rapid rate (Table 1). Such testing may have complex implications for the patient, other family members, and the broader community. The purpose of this review is to provide neurologists with a clinical perspective of the risks and benefits of DNA testing. In clinical practice these genetic testing scenarios can be divided into two major categories that have different strategies and implications: (1) testing symptomatic patients or (2) testing asymptomatic "at risk" patients.
Introduction
The past decade has witnessed a new development in the practice of neurology. Genetic research and technology have provided the knowledge and tools for the development of highly sensitive and specific DNA tests for neurogenetic disorders.[1] These tests directly identify mutations in disease causing genes. The number of diseases available for such testing is expanding at a rapid rate (Table 1). Such testing may have complex implications for the patient, other family members, and the broader community. The purpose of this review is to provide neurologists with a clinical perspective of the risks and benefits of DNA testing. In clinical practice these genetic testing scenarios can be divided into two major categories that have different strategies and implications: (1) testing symptomatic patients or (2) testing asymptomatic "at risk" patients.
