Discussion

Dr. N. V. B. Manyam: I would like to ask a question regarding Huntington's chorea. This is an autosomal dominant disease in which affected individuals show no evidence of disease until approximately age 30, i.e., well into the childbearing age. The concentrations of the amino acid γ‐amino butyric acid (GABA) are decreased in the brain and cerebrospinal fluid (CSF) of patients who die with this disease and in patients who are severely affected. We are conducting a study to determine whether the concentration of GABA is decreased in the spinal fluid of the offspring of persons with this disease. We currently feel we cannot disclose the results of our data until we have established whether individuals withdecreased CSF GABA are the ones who will ultimately develop the disease clinically, in about 20 years. In the process of obtaining informed consent from prospective participants in our study, we try to give a clear explanation that the results will not be revealed to them since we are unable to say presently whether a finding of reduced CSF GABA is predictive ofthe development of clinical disease. Nonetheless, parents of subjects or subjects who are pregnant or who are contemplating pregnancies ask for the results. Thus far, we have declined to disclose the values because of our inability to interpret them. Although we have informed consent, I am repeatedly disturbed about how to answer the question. Do others have suggestions on how to approach this problem?