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Metachromatic
leukodystrophy (MLD)
is a rare, inherited disease

Metachromatic leukodystrophy (MLD) is a rare, inherited disease

WHAT IS MLD?

MLD (metachromatic leukodystrophy) is a rare, inherited disease. In people with MLD, the lack of an enzyme called ARSA can destroy the protective layer of the nerves known as the myelin sheath. This damages the nerves and causes progressive motor issues, such as weakness and trouble walking, and a decline in brain function. MLD is ultimately fatal.

That’s why early diagnosis is so important.

There are multiple types of MLD that occur during various stages of childhood. When this disease occurs before a child is 30 months old, it is known as late infantile MLD. When it occurs after 30 months and before the age of 7, it is known as early juvenile MLD.

MLD IS A RARE DISORDER

ABOUT GENE THERAPY

What are genes?

Genes are small sections of DNA. Every person has 2 copies of each gene, 1 passed down—or inherited—from each parent.

Genes act as instructions to make proteins, the functional building blocks of the cell. Proteins are responsible for making sure that the cells in the body function properly. Much like a cookbook contains a recipe for a cake, a gene contains the instructions on how to make a protein.

A genetic variant is a change in the structure of a gene or group of genes. Many variants cause no harm, but others can cause genetic disorders, such as MLD.

What are genes?

Genes are small sections of DNA. Every person has 2 copies of each gene, 1 passed down—or inherited—from each parent.

Genes act as instructions to make proteins, the functional building blocks of the cell. Proteins are responsible for making sure that the cells in the body function properly. Much like a cookbook contains a recipe for a cake, a gene contains the instructions on how to make a protein.

A genetic variant is a change in the structure of a gene or group of genes. Many variants cause no harm, but others can cause genetic disorders, such as MLD.

Hematopoietic stem cells

A person’s body contains blood stem cells, otherwise known as hematopoietic stem cells (HSCs). HSCs are made in the bone marrow, which is the spongy tissue found in the center of most bones.

Stem cells can produce copies of themselves and create specialized blood cells of all types, including white blood cells, red blood cells, and platelets. The body uses these stem cells to make new cells when it needs them throughout a person’s life.

Hematopoietic stem cells

A person’s body contains blood stem cells, otherwise known as hematopoietic stem cells (HSCs). HSCs are made in the bone marrow, which is the spongy tissue found in the center of most bones.

Stem cells can produce copies of themselves and create specialized blood cells of all types, including white blood cells, red blood cells, and platelets. The body uses these stem cells to make new cells when it needs them throughout a person’s life.

IMPORTANT SAFETY INFORMATION

What is LENMELDY?

LENMELDY is a one-time gene therapy developed to treat children with pre-symptomatic late infantile, pre-symptomatic early juvenile and early symptomatic early juvenile, referred to as early-onset, metachromatic leukodystrophy (MLD). MLD is caused by a defect in the arylsulfatase A (ARSA) gene, which causes the body to produce reduced or no ARSA enzyme. LENMELDY is made specifically for each child, using the child’s own blood stem cells, and adding functional copies of the ARSA gene to their cells. This may allow you to produce sufficient ARSA enzyme to stop or slow the progression of MLD symptoms.

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