PT  - JOURNAL ARTICLE
AU  - K Ritz
AU  - M C F Gerrits
AU  - E M J Foncke
AU  - F van Ruissen
AU  - C van der Linden
AU  - M D I Vergouwen
AU  - B R Bloem
AU  - W Vandenberghe
AU  - R Crols
AU  - J D Speelman
AU  - F Baas
AU  - M A J Tijssen
TI  - Myoclonus–dystonia: clinical and genetic evaluation of a large cohort
AID  - 10.1136/jnnp.2008.162099
DP  - 2009 Jun 01
TA  - Journal of Neurology, Neurosurgery & Psychiatry
PG  - 653--658
VI  - 80
IP  - 6
4099  - http://jnnp.bmj.com/content/80/6/653.short
4100  - http://jnnp.bmj.com/content/80/6/653.full
SO  - J Neurol Neurosurg Psychiatry2009 Jun 01; 80
AB  - 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.