Huntington’s disease (HD) is a late-onset, progressive neurodegenerative disorder. It has an autosomal dominant inheritance pattern and is characterized by involuntary movements, psychiatric features, and cognitive deterioration. Symptoms usually present at 37 to 45 years of age and the disease has a fatal outcome 15 to 20 years later. European populations have a reported frequency of 1 in 10,000. In 1983, Gusella et al. localized the gene to the short arm of chromosome 4 and the gene was cloned in 1993, finding a CAG triplet which repeats 6 to 29 times in the normal population and 36 to 120 times in affected individuals. Several countries have had protocols for predictive and prenatal diagnosis of the disease since 1986. This disease has become a model for the study of the ethical, moral and social problems predictive testing entails.

More neurodegenerative disorders are discovered daily that share many similar characteristics with HD (late onset, progressive, disabling, and no preventive or curative therapy) such as ataxias (types 1, 2, and 3) and familial Alzheimer’s disease. In some of these, predictive diagnosis is also available.

The purpose of this study was to explore the knowledge and attitudes regarding the disease and its predictive and prenatal diagnosis of a group of Mexican specialists, who because of their medical specialty might come into contact with HD patients.

A self-administered, 30-item multiple-choice questionnaire was completed by 147 professionals. The questionnaire included sociodemographic data, questions regarding HD knowledge and previous experience with HD, opinions on predictive and prenatal diagnosis, and views regarding social assistance for patients and their families. Some questions were adopted from the Thies et al. survey prepared in Germany.

The distributions of continuous variables are described with means and standard deviations, in addition to categorical variables with simple percentages. To compare the distribution of each variable codified categorically among the different professionals (neurologists vs. psychiatrists vs. psychologists), we used the statistic Pearson’s ?². This statistical test was additionally used for comparing differences among categorical variables codified in a binary manner with Yates’ correction or Fisher’s exact test as appropriate. The alpha value was set at the 0.05 level.

Of the 147 professionals, 62 were neurologists, 43 psychiatrists, 39 psychologists, and 3 did not state their profession. Forty percent of the professionals worked in government institutions, 17% in private practice, 32% in both, 3% in universities, and 10% in more than two places. Mean age was 35 years (±8.12 SD) with a range of 21–65 years. Gender distribution was 65 (44%) female and 82 (56%) male. Seventy-eight percent of the professionals were religiously affiliated, 21% were not, and 1% did not reply.

Only 11 subjects (8%) answered positively in regard to providing genetic counseling. One hundred eighteen professionals (80%) preferred to refer couples to the genetics unit, 9 (6%) were ignorant of how to deal with the couples, 1 (0.6%) did not supply any information, and 8 (5%) did not reply. There was no statistically significant difference for this parameter among the different professional groups. Neurologists provided information with the highest frequency (64%), followed by psychiatrists (25%), and psychologists (11%).

One hundred five (74%) professionals admitted to knowledge on the availability of predictive diagnosis through DNA testing. Fifty-one percent were neurologists, 28%, psychiatrists, and 21%, psychologists, with a statistically significant difference among the groups (?² 13.47, p <0.001). Only 10% of participants were aware of the World Neurology Federation guidelines for HD protocols.

Results regarding the recommendation of carrying out a test for a person at risk for the disease. One hundred twenty-seven professionals would encourage the predictive test, of whom 55 were neurologists, 38 psychiatrists, and 34 psychologists. There was no statistically significant difference among the groups. When questioned about the reasons for recommending the test, 81 (55%) replied that they would only recommend it if the subject was considering having offspring, 61 (41%) would recommend it taking into consideration the patient’s professional reasons, 9 (6%) would recommend it only if a treatment existed, and 18 (12%) did not reply. No statistically significant difference was found among the groups of specialists (this question had more than one option for response).

A total of 57 neurologists, 34 psychiatrists, and 35 psychologists believed that predictive diagnosis must be carried out only in laboratories collaborating with a genetics unit providing back-up by neurologists, psychiatrists, and psychologists. Five neurologists, 6 psychiatrists, and 2 psychologists considered this unnecessary; 1 psychiatrist and 2 psychologists did not know, and 5 did not reply.

One hundred forty professionals considered that the results of predictive diagnosis must be disclosed under the supervision of a neurologist, a psychiatrist or psychologist, and a genetic counselor, while 4 replied that it was not necessary, 1 did not know, and 2 did not reply.

With a positive test, indicating that the person will develop the disease, subjects were asked about the influence it would have on the patient’s decision to have offspring. When questioned about prenatal diagnosis for a patient with HD, 53 neurologists, 38 psychiatrists, and 33 psychologists answered that they recommended it. Five neurologists, 2 psychiatrists, and 2 psychologists replied no, 4 neurologists, 3 psychiatrists, and 2 psychologists replied that they did not know, and 5 had no reply. Among those whose reply was affirmative 56 were females and 68 males. Ninety-seven professionals were religiously affiliated and 27 were not. Among those who answered “no”, 2 were female and 7 were male. Seven were religiously affiliated and two were not. Of those who responded that they did not know, 5 were female and 6 were male, among whom 9 were religiously affiliated.

This study shows that the group we surveyed does not have adequate knowledge of HD. Only 59% of the subjects stated that they knew about the inheritance risks of the disease, 20% of whom had an incorrect concept. The study demonstrated that most of the professionals (80%) chose to refer patients to a specialized unit and therefore not provide genetic counseling.

Although a large number of subjects (74%) knew of the possibility of predictive diagnosis, only 10% were aware of the recommended guidelines for HD programs of the World Federation of Neurology HD working group and the HD International Association, in spite of the fact that they were published in a journal widely distributed among mainly neurologists. This might explain the general willingness of the respondents to cooperate with a genetic unit instead of providing counseling HD themselves. One noteworthy fact is that 74% of the subjects acknowledged the possibility of predictive diagnosis for HD, yet only 55% had previous contact with HD patients or were familiar with the disease.