LBSL stands for Leukoencephalopathy with Brainstem and Spinal Cord Involvement and Lactate Elevation.
It’s a rare genetic disorder that affects the brain and spinal cord. There are thought to be approximately 100 to 300 patients worldwide, but many people go undiagnosed or misdiagnosed.
Identified in 2004, LBSL is caused by mutations in the DARS2 gene. DARS2 provides the body with instructions for making an enzyme called mitochondrial aspartyl-tRNA synthetase. LBSL is inherited in an autosomal recessive manner, meaning most patients have inherited two copies of the mutated gene – one from each parent. Parents who are carriers of the DARS2 mutation have a 25% chance of having a child with LBSL.
This enzyme helps with production of proteins in the mitochondria – the energy factories of our cells, which turn nutrients into energy.
As a result of DARS2 mutations, certain parts of the nervous system do not have sufficient energy to function properly. This affects their function and the production of nerve coatings, called myelin. Much like the plastic coating around the wires in your home, myelin provides insulation to the nervous system and is essential for the transmission of signals from the brain to the rest of the body.