Objective: To study the motor symptoms, psychiatric and neuropsychological features and genetic findings of patients with familial dystonia with or without myoclonus in a movement disorder center in Saudi Arabia.

Background: Discovery of mutations in the epsilon-sarcoglycan gene (SGCE), improve the ability to define the phenotype of many patients with primary myoclonus-dystonia (DYT11). Scarce information on DYT11 is reported in Arabic ethnic patients.

Methods: The database on familial dystonia with or without myoclonus from a movement disorder program in a tertiary medical center in Saudi Arabia was reviewed. The detailed demographic, clinical presentation, neuropsychological and psychiatric assessments were carried out. Blood screening for genes responsible for reported primary dystonia were done.

Results: Over a period of 11 years, 19 patients from 6 families met the diagnostic criteria for primary myoclonus-dystonia. The main age of onset of myoclonus is 5 years with a range of 18 months to 23 years. The dystonia associated or preceded the myoclonus in 3 patients. Asymmetrical dystonia affecting the lower limbs was seen in 7 patients which increased with walking. Action or posture myoclonus was seen in all except 2 patients and primarily involved the upper body. In three patients, the myoclonus affected the voice and or lower extremity. 4 patients had stimulus-sensitive myoclonus which was considered severe and disabling 8 patients. Psychiatric profile revealed depression, anxiety, panic, and phobic disorder in all the patients, obsessive compulsive features in 3 patients, substance and alcohol abuse in 5 patients and psychosis in one patient. No patient had a significant cognitive deficit. None described pathogenic heterozygous mutations SGCE were identified in 4 families while 2 had a previously described heterozygous mutation.

Conclusions: Mutation in epsilon sarcoglycan gene is the most common cause of familial dystonia with or without myoclonus among native Saudi patients. The clinical and psychological features encountered were not remarkably different compared with reports from other ethnic groups. The new mutations discovered in the SGCE gene increased the number of reported mutations in this condition.

« Back to 2016 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/the-phenotypic-and-genetic-features-of-myoclonus-dystonia-in-six-saudi-arabian-kindreds/