Myoclonus-dystonia: clinical and genetic evaluation of a large cohort.

BACKGROUND: Myoclonus-dystonia (M-D) is an autosomal dominant inherited movement disorder. Various mutations within the epsilon-sarcoglycan (SGCE) gene have been associated with M-D, but mutations are detected in only about 30% of patients. The lack of stringent clinical inclusion criteria and limitations of mutation screens by direct sequencing might explain this observation. METHODS: Eighty-six M-D index patients from the Dutch national referral centre for M-D underwent neurological examination and were classified according to previously published criteria into definite, probable and possible M-D. Sequence analysis of the SGCE gene and screening for copy number variations were performed. In addition, screening was carried out for the 3 bp deletion in exon 5 of the DYT1 gene. RESULTS: Based on clinical examination, 24 definite, 23 probable and 39 possible M-D patients were detected. Thirteen of the 86 M-D index patients carried a SGCE mutation: seven nonsense mutations, two splice site mutations, three missense mutations (two within one patient) and one multiexonic deletion. In the definite M-D group, 50% carried an SGCE mutation and one single patient in the probable group (4%). One possible M-D patient showed a 4 bp deletion in the DYT1 gene (c.934_937delAGAG). CONCLUSIONS: Mutation carriers were mainly identified in the definite M-D group. However, in half of definite M-D cases, no mutation could be identified. Copy-number variations did not play a major role in the large cohort.

Pediatric writer's cramp in myoclonus-dystonia: maternal imprinting hides positive family history.

Myoclonus-dystonia (M-D) is an autosomal dominantly inherited movement disorder with myoclonic jerks and dystonic contractions most frequently due to a mutation in the epsilon-sarcoglycan (SGCE, DYT11) gene. We describe two unrelated children with M-D (DYT11) who presented with writer's cramp. Due to maternal imprinting the family history appeared initially negative for M-D. In children with writer's cramp screening of the SGCE gene should be considered, even with a negative family history.

Recovery of posterior communicating artery aneurysm-induced oculomotor palsy after coiling.

BACKGROUND AND PURPOSE: Recovery of oculomotor (cranial nerve [CN] III) palsy after surgery of posterior communicating artery (PcomA) aneurysms has been well documented, but recovery after coiling is poorly understood. In this study, we report the recovery after coiling of PcomA aneurysm-induced CN III palsy in 21 patients at follow-up of 1 to 7 years. MATERIALS AND METHODS: Of 135 patients with a PcomA aneurysm treated with coils between January 1997 and December 2003, there were 21 patients with initial CN III dysfunction who were selected and reevaluated. There were 2 men and 19 women with a mean age of 54.9 years. In 17 patients, CN III palsy was associated with subarachnoid hemorrhage (SAH). Timing of treatment after onset of symptoms was 1 to 3 days in 5 patients, 4 to 14 days in 13, and more than 14 days in 3. Mean size of the aneurysm was 9 mm. Initial CN III palsy was complete in 15 patients and partial in 6. Mean follow-up after coiling was 3.7 years (range, 1-7 years). RESULTS: Of 15 patients with initial complete CN III palsy, recovery was complete in 3 and partial in 10. In 2 patients, complete CN III palsy was unchanged. Of 6 patients with initial partial CN III palsy, recovery was complete in 5 and partial in 1. Initial partial CN III palsy was the only predictor of complete recovery at follow-up. CONCLUSION: PcomA aneurysm-induced CN III palsy improves or cures after coiling in most patients. Complete recovery is more likely with initial partial dysfunction of the nerve.

Distal myoclonus and late onset in a large Dutch family with myoclonus-dystonia.

We report a large myoclonus-dystonia (M-D) pedigree with a two-base pair deletion in Exon 5 of the epsilon-sarcoglycan gene. Three individuals had onset after age 40 years. Distal myoclonus of the arms was present in all 20 symptomatic mutation carriers. These findings expand the known phenotype of M-D and require revision of the current diagnostic criteria. Five of 14 asymptomatic mutation carriers who inherited the mutation from their mother showed minimal axial dystonia, arguing against a maternal imprinting mechanism.

Phenotype-genotype correlation in Dutch patients with myoclonus-dystonia.

The epsilon-sarcoglycan (SGCE) gene is an important cause of myoclonus-dystonia (M-D), although the majority of cases with an M-D phenotype test negative. Seven of 31 patients with the M-D phenotype carried a mutation in the SGCE gene. Positive family history and truncal myoclonus were independent prognostic factors. Early disease onset, onset with both myoclonus and dystonia, and axial dystonia were detected significantly more often in the mutation carriers.