[Phenomenon of anticipation in a patient with dystrophic myotonia type 1].

The article presents the authors' clinical observation of a patient with genetically confirmed dystrophic myotonia type 1 and describes the phenomenon of anticipation associated with an increase in the severity of symptoms, an earlier onset of the disease in each subsequent generation, and due to an increasing expansion and the sex of the parent transmitting the mutation. In the described family case, dystrophic myotonia type 1 was observed in four generations. It was inherited through the maternal line as an increase in the number of trinucleotide repeats in the DMPK gene and the severity of clinical symptoms in patients.