Online Supplemental Data: (E)-Appendix 2

Online Supplemental Data: (E)-Appendix 2

Review of Previously Published Cases of SGCE Mutations

Table one gives summary clinical features of all published cases positive for SGCE mutations. We selected published papers based on a PubMed search using the search terms “epsilon”, “sarcoglycan” and “SGCE”. We only included patients if they had been examined by a neurologist, not those in whom the details of the movement disorder were by history alone, and then only if sufficient clinical details were included in the paper. Using these criteria we identified 66 patients from eight published papers. 1-8 These patients showed a young age of onset (mean age 7; range 1-30 years), with myoclonus-dystonia as the predominant phenotype (88%). Six cases (9%) were reported to have myoclonus only, and one case (1%) was reported with dystonia as the sole clinical feature. Myoclonus and dystonia were predominantly seen in the neck and upper body, with the lower body being either unaffected (80% of cases unaffected by lower body myoclonus; 66% unaffected by lower body dystonia) or only mildly so. Alcohol responsiveness was seen in 93% of those where such information was recorded (62% of all cases). Psychiatric disturbance was noted in 64% of those where such information was recorded (48% of all cases). In many of these cases, psychiatric disturbance was not assessed by a formal psychiatric evaluation, and whether DSM IV criteria were met in all cases is not clear.

Table 1. Summary of clinical features of 66 previously published patients with SGCE mutations

Phenotype (%) / Mean age of onset / years (range) / Distribution of Myoclonus (%) / Distribution of Dystonia (%) / Alcohol Response (%) / Psychiatric symptoms (%)
M: 6 (9)
D: 1 (1)
MD: 59 (88) / 7 (0.5-30) / upper body only: 53 (80)
upper and lower body: 12 (19)
lower body only: 0 (0)
no myoclonus: 1 (1) / upper body only: 44 (66)
upper and lower body: 15 (23)
lower body only: 1 (1)
no dystonia: 6 (9) / yes: 41 (62)
no: 3 (4)
NK: 23 (35) / yes: 32 (48)
no: 18 (27)
NK: 16 (24)

M = Essential Myoclonus; D = Dystonia; MD = Myoclonus Dystonia; NK = not known.

References

1. Zimprich A, Grabowski M, Asmus F et al. Mutations in the gene encoding -sarcoglycan cause myoclonus-dystonia syndrome. Nature Genet 2001; 29: 66-9.

2. Han F, Lang AE, Racacho L, Bulman DE, Grimes DA. Mutations in the -sarcoglycan gene found to be uncommon in seven myoclonus-dystonia families. Neurology 2003; 61: 244-6.

3. Asmus F, Zimprich A, Tezenas du Montcel S et al. Myoclonus-dystonia syndrome: -sarcoglycan mutations and phenotype. Ann Neurol 2002; 52: 489-92.

4. Maréchal L, Raux G, Dumanchin C et al. Severe myoclonus-dystonia syndrome associated with a novel epsilon-sarcoglycan gene truncating mutation. Am J Med Genet 2003; 119B: 114-7.

5. Doheny D, Danisi F, Smith C et al. Clinical findings of a myoclonus-dystonia family with two distinct mutations. Neurology 2002; 59: 1244-6.

6. Doheny DO, Brin MF, Morrison CE et al. Phenotypic features of myoclonus-dystonia in three kindreds. Neurology 2002; 59: 1187-96.

7. Foncke EMJ, Klein C, Koelman JHTM et al. Hereditary myoclonus-dystonia associated with epilepsy. Neurology 2003; 60: 1988-90.

8. Hjermind LE, Werdelin LM, Eiberg H, Krag-Olsen B, Dupont E, Sorensen SA. A novel mutation in the epsilon-sarcoglycan gene causing myoclonus-dystonia syndrome. Neurology 2003;60(9):1536-9.