Metachromatic Leukodystrophy

Symptoms

The symptoms of metachromatic leukodystrophy vary, depending on the age they develop and in degree of severity.

Because metachromatic leukodystrophy is relatively rare, and the symptoms mimic other diseases, patients with MLD may be misdiagnosed. Children may be diagnosed with cerebral palsy, deterioration in learning skills or behavioral disturbances. For people with late juvenile or adult MLD, early symptoms may mimic mental illness or psychiatric disorders.

There are four forms of MLD. The forms and their symptoms are:

Late Infantile

This is the most common form of metachromatic leukodystrophy. Symptoms appear at age 4 or younger and may include:

• Loss of motor development milestones, such as losing the ability to walk or stand up
• Problems walking (gait disturbances)
• Behavioral changes, such as increased irritability or decreased attention span
• Slurred speech and problems talking (speech disturbances)
• Difficulty with feeding and swallowing
• Loss of memory
• Loss of vision
• Seizures may be present

The loss of brain and body functions progresses fairly rapidly, with death usually occurring within five to 10 years from the time symptoms appear.

Early Juvenile

Symptoms appear between the ages of 4 to 6 and may include:

• Problems walking (gait disturbances)
• Loss of previously achieved physical and mental skills, such as developing incontinence (the child may not be able to control urination or bowel movements)
• Behavioral changes, such as a decline in school performance
• Decline in intellectual, or thinking, abilities
• Muscle tremors, spasms or loss of muscle tone
• Decreased attention span
• Seizures may be present

Although this form of MLD progresses more slowly than the infantile form, death usually occurs within 10 to 20 years of symptoms appearing.

Late Juvenile and Adult

The initial symptoms of these forms of MLD are change in personality and behavior, leading to frequent misdiagnosis of psychiatric disorders. Symptoms appear in the late teens or older and may include:

• Change in personality or behavior, such as a decline in performance at school or on the job
• Behavior that is increasingly impulsive or uninhibited
• Behavioral problems that may be diagnosed as mental illness, or psychiatric disorders
• Problems walking (gait disturbances) and stiffness in the legs
• Numbness, tingling and pain in the hands and feet
• Progressive decline in intellectual (thinking) abilities

As the disease progresses, patients will lose the ability to perform daily living activities and need to be monitored continually, including feeding. Patients with these late-onset forms of MLD can have very slow progressive decline, lasting for decades. However, their life span is shortened due to the disease.