Confidentiality and Huntington's chorea.

A doctor has duties towards his patients of both confidentiality and veracity and at times these may conflict, as in the following case. A mother who has the symptoms of Huntington's chorea does not wish her daughters to know. The doctor must try to make her realise how valuable the information can be to the daughters, and thus obtain her consent to inform them. If the mother's consent cannot be obtained, then the doctor must tell the mother that he cannot allow her attitude to deprive the daughters of this information, especially at this crucial time as they plan to have children. The well-being of the daughters' future families must take precedence over the mother's desire for secrecy regarding her condition.     

Tetrabenazine in the treatment of Huntington's chorea.

The effectiveness of tetrabenazine in controlling choreic movement in Huntington's chorea has been confirmed in a long-term study. Side effects noted included postural hypotension, dysphagia and pneumonia. Careful supervision of patients taking this effective agent is urged.     

Genetic prediction and family structure in Huntington's chorea

A deoxyribonucleic acid marker linked to the locus for Huntington's chorea exists, but its possible use in the prediction of this disorder depends on the pedigree structure of individual families. Analysis of data from a population register for Huntington's chorea in south Wales showed that only a minority of subjects at risk had the appropriate members of their family living to allow the presence or absence of the gene to be definitively predicted. However, the structure of the family allowed a degree of prediction (in particular, exclusion of the disorder) to be made for the fetus during pregnancies of these subjects in almost 90% of cases. Such a prediction need not alter the risk state for the parent at risk. The structure of the family will remain crucial for prediction even when current limitations of the linked marker have been overcome.     

Platelet monoamine uptake in relatives of patients with Huntington's chorea

Uptake of dopamine and 5-hydroxytryptamine (5-HT) by the platelets of 25 symptom-free relatives of patients with established Huntington's chorea (HC) was not significantly different from that of control subjects. Platelet uptake of 5-HT in 3 subjects with early signs of the disease showed increased Km and Vmax values. Increased platelet uptake of 5-HT in patients with established HC was confirmed in a further 3 patients. It seems that this phenomenon appears with the clinical evidence of the disease. Further investigation of the nature of the platelet uptake abnormality may cast light on pathogenic factors in HC.     

Juvenile variant of Huntington's chorea. An expression of disturbed neurotransmission

A case of a young woman suffering from a juvenile variant of Huntington's chorea, in which rigidity presented as the predominant motor abnormality is reported. The patient's symptoms were relieved by therapy with levodopa. The underlying disturbance of neurotransmission is discussed.     

Ethical aspects of genetic counselling

The author, a scientist working in clinical genetics, outlines the functions of the genetic counsellor and discusses some of the ethical issues involved. The paper is based on one given at a London Medical Group conference.     

Ethics of predictive testing for Huntington's chorea: the need for more information

The finding of a genetically linked polymorphic DNA marker has made possible a predictive test for Huntington's chorea. This DNA probe has so far been used only for research and has technical limitations, but some workers now wish to apply it to clinical predictions. Those identified by the probe as being probable carriers of the Huntington's chorea gene would be exposed to uncertain psychological risks and social pressures. Ethical guidelines should be established, but these require greater knowledge of the potential benefits and hazards of this powerful new procedure. Controlled clinical trials are urgently needed.