Fifteen-year follow-up of a patient with a DHDDS variant with non-progressive early onset myoclonic tremor and rare generalized epilepsy

Abstract

Background: Generalized epilepsy and tremor phenotypes have been reported in some genetic disorders. Among them benign adult familial myoclonus epilepsy (BAFME) has been confirmed as a clearly defined clinical and genetic entity. On the other hand, non-progressive tremor and generalized epilepsy phenotypes have also been reported in patients with DHDDS variants.

Case presentation: We report on a long term follow-up of patient with de novo missense variant of DHDDS, who revealed non progressive nature. This 18-year-old woman presented non-progressive tremor since her early infancy. She had rare seizures. Her tremor was considered as cortical myoclonic tremor with giant somatosensory evoked potentials.

Conclusion: In patients with early onset, non-progressive tremor and rare generalized epilepsy phenotypes, DHDDS variants may be considered in the genetic differential diagnosis.

Keywords: BAFME; Benign adult familial myoclonus epilepsy; DHDDS; Dystonia; Generalized epilepsy; Myoclonic tremor.