Definition:

Leukoencephalopathy with brain stem and spinal cord involvement and brain lactate elevation (LBSL) is an autosomal recessive juvenile to adult-onset white matter disorder presenting with slowly progressive pyramidal, cerebellar and dorsal column dysfunction, often leading to wheelchair dependency before age 30 years. LBSL is caused by mutations in the gene DARS2, which codes for mitochondrial aspartyl-tRNA synthetase (mtAspRS).