| Definition: |
An adult onset demyelinating leukodystrophy that is characterized by pyramidal signs with weakness and spasticity, dysarthria, dysautonomia, and white matter alterations affecting the cerebrum and corticospinal tracts while sparing the cerebellum and that has_material_basis_in heterozygous deletion involving regulatory elements upstream of the LMNB1 gene on chromosome 5q23. Atypical ADLD can be distinguished from typical ADLD by lack of early involvement of the autonomic nervous system and sparing of the cerebellum clinically and on brain imaging. |