Congenital Mirror Movements Due to RAD51: Cosegregation with a Nonsense Mutation in a Norwegian Pedigree and Review of the Literature

BACKGROUND Autosomal dominant congenital mirror movements (CMM) is a neurodevelopmental disorder characterized by early onset involuntary movements of one side of the body that mirror intentional movements on the contralateral side; these persist throughout life in the absence of other neurological symptoms. The main culprit genes responsible for this condition are RAD51 and DCC. This condition has only been reported in a few families, and the molecular mechanisms linking RAD51 mutations and mirror movements (MM) are poorly understood. METHODS We collected demographic, clinical, and genetic data of a new family with CMM due to a truncating mutation of RAD51. We reviewed the literature to identify all reported patients with CMM due to RAD51 mutations. RESULTS We identified a heterozygous nonsense mutation c.760C>T (p.Arg254*) in eight subjects: four with obvious and disabling MM, and four with a mild phenotype. Including our new family, we identified 32 patients from 6 families with CMM linked to RAD51 variants. DISCUSSION Our findings further support the involvement of RAD51 in CMM pathogenesis. Possible molecular mechanisms involved in CMM pathogenesis are discussed.