Metachromatic leukodystrophy, late infantile form

Metachromatic leukodystrophy (MLD), late infantile form, is a rare inherited metabolic disease that affects the nervous system. It is also known as late infantile MLD or arylsulfatase A deficiency. The disease is caused by a shortage of an enzyme called arylsulfatase A (ARSA), which is needed to break down certain fatty substances called sulfatides. When sulfatides build up in the body, they damage the protective covering (myelin) around nerve fibers in the brain and throughout the body. This process is called demyelination, and it leads to progressive loss of motor and mental abilities. The late infantile form is the most common and most severe type of MLD. Symptoms typically begin between ages 1 and 2.5 years. Children who were developing normally begin to lose skills they had already learned, such as walking and talking. Early signs include clumsiness, frequent falls, and difficulty walking. Over time, children lose the ability to move, speak, swallow, and see. Seizures may also occur. The disease progresses rapidly, and most children become fully dependent on caregivers within a few years of symptom onset. The treatment landscape has changed significantly in recent years. In 2024, the FDA approved atidarsagene autotemcel (Lenmeldy), a gene therapy for pre-symptomatic or early symptomatic children with the late infantile form. Hematopoietic stem cell transplantation (bone marrow transplant) has also been used, though its benefit in the late infantile form is limited once symptoms have begun. Supportive care remains essential and includes physical therapy, nutritional support, and management of symptoms like seizures and pain.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Bring these to your next appointment

• Q1.Is my child a candidate for gene therapy (Lenmeldy), and how quickly can we pursue this?,How advanced is the disease based on the MRI and clinical exam, and what does this mean for treatment options?,Should my other children or family members be tested for MLD or carrier status?,What supportive therapies should we start right away to help maintain my child's abilities?,What should our emergency plan be for seizures or breathing problems?,Are there any clinical trials my child might be eligible for?,How can we access palliative care and family support services?

Common questions about Metachromatic leukodystrophy, late infantile form

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Other rare diseases commonly researched alongside Metachromatic leukodystrophy, late infantile form.

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