Leukoencephalopathy with Brainstem and Spinal Cord Involvement and Lactate Elevation (LBSL)
Leukoencephalopathy with Brainstem and Spinal Cord Involvement and Lactate Elevation (LBSL)
OMIM number: 611105
Comments closing date: 13/06/2025
Leukoencephalopathy with brain stem and spinal
cord involvement and lactate elevation (LBSL) is a
rare autosomal recessive mitochondrial condition
caused by mutations in the DARS2 gene on
chromosome 1. Affected children have complex
clinical problems caused by brain stem and spinal
cord involvement. Age of onset can be infantile,
childhood or adult. However in all cases the
condition is progressive. For the most severe
types, it often leads to death in childhood due to
respiratory failure. Symptoms include global
developmental delay, poor muscle tone, and
breathing difficulties. MRI scans show brain white
matter abnormalities with high levels of lactate.
Nystagmus (uncontrolled movement of eyes)
leads to poor vision. Some will also have seizures.
With early onset forms, few motor skills are
achieved. With later onset, motor skills are
achieved and then deteriorate until movement is
severely impaired due to ataxia (unstable gait),
tremor, and stiffness (spasticity). Progression of
the childhood type will lead to wheelchair
dependence by late teens. Speech and learning
ability may deteriorate. The adult type is more
slowly progressive.
Review date: 16 May 2027
