Mirror movements are involuntary, symmetrical and simultaneous movements occurring on one side of the body that accompany controlateral voluntary movements. Congenital mirror movements (CMM) are characterized by childhood onset and the absence of additional manifestations. The aim of this study is to unravel the pathophysiology of the CMM that remains poorly elucidated. The combination of imaging studies and neurophysiological studies using transcranial magnetic stimulation in a homogeneous and relatively large group of patient is likely to allow us to better understand the underlying pathophysiology of the disorder. Using a linkage analysis approach we will try to identify a locus associated with CMM and related candidate genes.

Inclusion Criteria:

• Patients aged from 11 to 82 years
• Members of the family of interest displaying mirror movements or being obligatory asymptomatic carrier, without additional manifestation or malformation; or patient with genetically proven Kallmann syndrome and mirror movements.
• No contraindication for MRI or TMS study

Exclusion Criteria:

• inability to provide an informed consent
• Simultaneous participation in another clinical trial
• Treatment that modulate cortical excitability (for the TMS part of the study only)