An 18-year-old man had synkinetic hand movements1 since early childhood (video 1), with stable course, and without other neurologic disorders. His mother and first cousin (figure 1) also had mild mirror movements in their hands.
Figure 1. Pedigree of the family with congenital mirror movements illustrating a probable autosomal dominant inheritance (the first cousin declined to carry out the genetic study).
Phenomenology of the mirror movements. Fragment 1: There is no movement of the left foot when performing movements with the right. Fragment 2: When one hand moves, the other hand involuntarily performs a similar movement. The movements occur in both the right hand and the left. Fragment 3: The more vigorous the voluntary movements, the more intense the mirror movements.Download Supplementary Video 1 (15.9MB, mov) via http://dx.doi.org/10.1212/010599_Video_1
MRI brain was normal (figure 2, A and B) but the functional MRI signals showed blood flow in both primary motor cortices and supplementary motor areas during movements of either the right hand (figure 2C) or left hand (figure 2D).
Figure 2. MRI brain.
Sagittal T1-weighted (A) and axial T2-weighted (B) images showed no brain injury. The arrowheads indicate the normal appearance of the corpus callosum. Functional MRI study (C, D) during opening or closing movement of the hand. The movement of each hand separately produced a bilateral activation of both primary motor cortices, predominantly in the left when moving the right hand (C) and again predominantly in the left with the movement of the left hand (D).
We excluded alternative diagnoses, such as X-linked Kallman or Klippel-Feil syndrome. A novel mutation leading to a frameshift (c.784_785del p.Val263Phefs*21) was identified in exon 4 of the DCC gene2 in the patient and his mother. DCC gene mutations lead to truncated DCC protein that is receptor for netrin-1 that guides the development of CNS axons across the body's midline.2
Acknowledgment
The authors thank the patient and his family.
Appendix. Authors
Footnotes
Teaching slides links.lww.com/WNL/B185
Study funding
No targeted funding reported.
Disclosure
The authors report no disclosures relevant to the manuscript. Go to Neurology.org/N for full disclosures.
References
- 1.Méneret A, Depienne C, Riant F, Trouillard O, Bouteiller D, Cincotta M. Congenital mirror movements: mutational analysis of RAD51 and DCC in 26 cases. Neurology 2014;82:1999–2002. [DOI] [PMC free article] [PubMed] [Google Scholar]
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Supplementary Materials
Phenomenology of the mirror movements. Fragment 1: There is no movement of the left foot when performing movements with the right. Fragment 2: When one hand moves, the other hand involuntarily performs a similar movement. The movements occur in both the right hand and the left. Fragment 3: The more vigorous the voluntary movements, the more intense the mirror movements.Download Supplementary Video 1 (15.9MB, mov) via http://dx.doi.org/10.1212/010599_Video_1