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

Abstract

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.

Psychiatric disorders, myoclonus dystonia, and the epsilon‐sarcoglycan gene: A systematic review

“…Our literature review identified 22 nonduplicated publications, which were classified as single‐family,7, 22, 23, 25, 28–32 multiple‐family,1–4, 9, 15, 20, 33 and larger‐scale studies with sequential probands or multiple unrelated cases26, 27, 34–36 (Supplementary Table 1).…”

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

“…This is in line with previous findings. However, patients with a typical M-D phenotype and a young-onset with a negative family history as well as patients with a typical M-D phenotype, late onset but a positive family history should also be considered for genetic testing, as mutation carriers with a late age of onset have been reported in a Dutch M-D pedigree 16. Possible M-D cases do not need to be tested for SGCE mutations.…”

The intermuscular 3–7 Hz drive is not affected by distal proprioceptive input in myoclonus-dystonia

“…MD is an autosomal dominant hereditary form of dystonia characterized by myoclonic jerks and dystonic postures or movements of the upper body. The condition usually becomes clinically manifest within the first two decades of life and is alcohol responsive (Foncke et al 2006; Gerrits et al 2006). In MD patients, the low-frequency drive had been reported at 3–7 Hz (Foncke et al 2007b).…”