White matter and gray matter make up the different tissues in the brain, according to the University of Maryland Medical Center. The National Institutes of Health (NIH) notes that white matter contain nerve fibers, or axons; these are covered by myelin, a protein and fatty substance that gives white matter its color. Myelin insulates the axon, allowing for a quicker transmission of electrical signals down a neuron. One rare disorder, leukoencephalopathy, has genetic mutations that results in a destruction of myelin, or “vanishing white matter.”
The US National Library of Medicine states that the most common form of leukoencephalopathy with vanishing white matter has a childhood onset, meaning no symptoms present during infancy. Noticeable symptoms of leukoencephalopathy with vanishing white matter are motor symptoms, such as ataxia (problems coordinating movements) and spasticity (abnormal muscle stiffness); mental problems can also be present, though the US National Library of Medicine states this is not as severe as the motor symptoms). The United Leukodystrophy Foundation adds that lethargy, fever, seizures and eye problems are also possible; in severe cases, coma and death can occur.
In milder forms, symptoms can begin during adolescents or adulthood, with behavioral symptoms appearing first. Women who have a mild for of leukoencephalopathy with vanishing white matter can have a variation known as ovarioleukodystrophy, where there is ovarian dysfunction, such as ovarian dysgenesis (abnormal development of the ovaries).
The deterioration of the white matter is not a steady progression: The US National Library of Medicine notes that the patient has “periods of relative stability interrupted by episodes of rapid decline.” Stress is a large factor in the severity of symptoms: It may trigger the onset or exacerbate current symptoms. The connection between stress and loss of white matter is genetics -- mutations in the genes that make the protein eIF2B. Leukoencephalopathy with vanishing white matter has an autosomal recessive pattern, where each parent has a mutated gene; however, the parents can be carriers and have no symptoms if they carry only one gene each. The genes that have been identified are EIF2B1, EIF2B2, EIF2B3, EIF2B4, and EIF2B5, with the US National Library of Medicine noting that 65 percent of cases are due to a mutation of the EIF2B5 gene.
When one of these genes are mutated, it affects the protein's ability to function and regulate itself. The US National Library of Medicine notes that “researchers believe that cells in the white matter may be particularly affected by an abnormal response to stress, resulting in the signs and symptoms of leukoencephalopathy with vanishing white matter.” No cure exists for this disorder, though patients may benefit from physical therapy to manage muscular problems.
Elizabeth Stannard Gromisch received her bachelor’s of science degree in neuroscience from Trinity College in Hartford, CT in May 2009. She is the Hartford Women's Health Examiner and she writes about abuse on Suite 101.