In genetic disease, who has the right to know—or not know—what?

IN THISHDHD information-saturated age, what happens when the right to know comes up against the right not to know? The ease of genetic testing has brought this question to the fore. Genes, some of which contain disease-causing mutations, are shared within families, meaning the results of a test for a genetic condition inevitably affect more people than the one who consented to be tested. Two contrasting legal cases pitting these rights against each other—one in Britain, the other in Germany—stand to extend the idea of who, exactly, is a patient and to alter the way in which medicine is practised.Both cases involve Huntington’s disease (), a heritable neurodegenerative disorder. A single mutation gives rise to , meaning that every child of an affected parent has a 50% chance of inheriting it. Symptoms, which include loss of co-ordination, mood changes and cognitive decline, tend to develop between the ages of 30 and 50, and the disease is ultimately fatal. Diagnosis is based on a simple blood test, and though there are treatments for the symptoms, there is as yet no cure.