Vanishing White Matter disease (VWM), also known as Childhood Ataxia with Central Nervous System Hypomyelination (CACH), is a neurological condition that destroys myelin, the brain’s white matter. In doing so, it permanently affects transmission of brain signals to the rest of the body.

White matter is the tissue through which messages pass in the central nervous system. The white matter is white because of the fatty substance (myelin) that surrounds the nerve fibers (axons). This myelin acts as an electrical insulation, allowing the messages to pass quickly from place to place. The loss of myelin essentially means the sufferer’s brain loses the ability to send signals to the rest of the body, and the signals that do get through are often slower than normal.

VWM is one of about 40 conditions that affect the white matter of the brain known collectively as Leukodystrophies. It is extremely rare, in fact there are currently less than 250 people worldwide who are known to suffer from the disease.

VWM is chronic and progressive, and is unusual in that periods of rapid and severe deterioration can be caused by minor head trauma, fevers and even anesthesia. Currently, VWM is untreatable, incurable and terminal.

Symptoms generally appear in young children (usually between 2 – 6 years old) who were previously developing fairly normally. The severity of the disease is strongly correlated to the age of onset. While every patient is different, as the disease progresses, sufferers can expect some or all or the following symptoms: loss of motor skills (walking usually goes first, followed by ability to sit unassisted, speech, use of hands, head control and ability to swallow), loss of vision, epileptic seizures, vomiting, irritability, and comas. Few sufferers survive more than 5-10 years after onset.  As there is no treatment for the disease, symptoms are treated individually as they appear.

The pattern in which the myelin is destroyed in VWM patients means that it primarily affects patients physically; cognitively they remain relatively unaffected.

What causes VWM?

VWM is a recessive genetic disease, which means that both parents carry a mutation on the same gene that has been inherited by their child. Each child of carrier parents has a 25% chance of having VWM, a 50% chance of being a carrier and a 25% of being unaffected.

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VWM is caused by a mutation on one of 5 EIF2B genes (EIF2B1, EIF2B2, EIF2B3, EIF2B4 and EIF2B5).  The parent carriers need to have a mutation on the same EIF2B gene for the child to have VWM.

Each parent mutation is different, so each child has a unique pair of mutations.  The combination of these 2 mutations determines the severity of the disease.  For this reason, the severity of the disease is completely individual, depending on the combination of mutations that each child has.
For this reason as well, it is impossible with current technology to do across the board prenatal screening for VWM.  If you know your mutations, you can screen prenatally, but results wouldn’t be available until about 16 weeks pregnant.