Clinical and genetic knowledge and attitudes of patients with myotonic dystrophy type 1.

AIMS: The goal was to assess clinical and genetic knowledge and attitudes in patients affected by myotonic dystrophy type 1 (DM1). METHODS: Two hundred patients with molecular confirmation of the diagnosis of DM1 completed a multi-choice questionnaire. DM1 patients' knowledge and views were compared to clinically normal DM1 noncarriers (n = 264) and controls (n = 1,474). RESULTS: Knowledge of the DM1 mode of inheritance was better in noncarriers than in patients (p < 0.001). Noncarriers were more aware than DM1 patients of the common clinical characteristics of DM1 such as limitations in physical activities and problems related to employment, schooling, activities of daily living, parenthood, peer relationships, and personality (p < 0.001). Compared to controls, DM1 patients felt less informed about the availability of clinical genetic services (p < 0.05) and new genetic technologies (p < 0.001). Among patients, logistic regression revealed that each additional year of education (p < 0.05) and each additional 100 CTG repeats (p < 0.01), respectively, increased and decreased the odds of knowing the DM1 mode of inheritance by about 23% and 18% respectively, independently of age, age at onset of symptoms, gender, severity of muscular impairment, and intellectual quotient. CONCLUSIONS: DM1 patients' genetic knowledge is significantly dependent of the level of education and the number of CTG repeats. Healthcare providers should be aware of this situation in order to adjust counselling and education accordingly.