Plasma ASN level is not valuable marker of the disease. It does not differ in subtypes of the disease. There is relation between plasma ASN level and the severity of the disease in PIGD subtype.

The N370S GBA mutation is the risk factor for cognitive impairment in PD patients.

The HFS-36 score depends mostly on severity of HFS, depressive symptoms and occurrence of accompanying trismus. It improves after BTX-A treatment.

Our results confirm the role of the SGCE gene in the pathogenesis of MDS and call into question the impact of SGCE mutations on the age of onset. The existing list of known mutations and diversity of symptoms in patients bearing the same mutation indicates that there is a lack of genotype-phenotype correlation. Heterogeneity of disease indicates necessity for further research in order to find the molecular fingerprint which may be a landmark in diagnostic studies of MDS.

Aim of the study. This paper describes six cases of patients with myoclonus-dystonia syndrome who are members of a family in which an SGCE gene mutation has been confirmed.Clinical rationale for the study. Myoclonus-dystonia syndrome is a very rare disease, with an incidence in Europe of about 2 in every million. Due to the fact that only a few case reports of this illness are accessible in the literature, the material we collected seems to be valuable for clinical practice. Materials and methods.A history was taken, and physical and genetic examinations of the patients were performed. Furthermore, the clinical examination of three patients was video-recorded.Results. The clinical picture of the disease varied significantly between the described individuals, from a healthy carrier of the SGCE mutation to patients presenting mild to moderate symptoms. The differences concerned the age at onset of the disease, the initial symptoms, the intensity of involuntary movements, and the predominant symptoms. In addition to the typical movement disorders which are myoclonus and dystonia, in the described family there was also the coexistence of epilepsy, obsessive-compulsive behaviour, dyslexia, dysgraphia, non-harmonious development of cognitive processes, as well as mild phenotypic features of muscular dystrophy. The mutation (NM_001099401.2:c.806-809delACTG) found in the presented family has not been described elsewhere. Conclusions and clinical implications.Our description of six cases of patients demonstrates the heterogeneity of the natural course of the disease, even in patients with the same mutation. It seems reasonable to regularly examine relatives of patients with myoclonus-dystonia syndrome, who should be observed for involuntary movements as well as non-motor symptoms.