Adult-onset autosomal dominant leukodystrophy (ADLD) is a slowly progressive 
neurological disorder characterized by symmetrical widespread myelin loss in the 
central nervous system, with a phenotype similar to chronic progressive multiple 
sclerosis. In this study, we identify a genomic duplication that causes ADLD. 
Affected individuals carry an extra copy of the gene for the nuclear laminar 
protein lamin B1, resulting in increased gene dosage in brain tissue from 
individuals with ADLD. Increased expression of lamin B1 in Drosophila 
melanogaster resulted in a degenerative phenotype. In addition, an abnormal 
nuclear morphology was apparent when cultured cells overexpressed this protein. 
This is the first human disease attributable to mutations in the gene encoding 
lamin B1. Antibodies to lamin B are found in individuals with autoimmune 
diseases, and it is also an antigen recognized by a monoclonal antibody raised 
against plaques from brains of individuals with multiple sclerosis. This raises 
the possibility that lamin B may be a link to the autoimmune attack that occurs 
in multiple sclerosis.