Using a linkage analysis and a candidate gene approach, two genes have been implicated in congenital MRMV disorder to date: DCC on 18q21.2 (MRMV1), which encodes a netrin receptor, and RAD51 on 15q15.1 (MRMV2), which is involved in the maintenance of genomic integrity.
DCC mutations result in variable dominant phenotypes with decreased penetrance, including mirror movements and ACC associated with a favorable developmental prognosis.
Diverse connectivity abnormalities were identified in mutation carriers with and without mirror movements, but corticospinal effects and decreased peripheral DCC mRNA appeared driven by the mirror movement phenotype.ANN NEUROL 2019;85:433-442.
Summary of literature data describing heterozygous loss-of-function variants in DCC (n = 61) revealed 63.9% penetrance for mirror movements, 9.8% for ACC, and 5% for both.