Metachromatic leukodystrophy (MLD) is a rare and life-threatening genetic disease
MLD is an autosomal recessive lysosomal storage disorder caused by the lack of an enzyme called arylsufatase A (ARSA)
An autosomal recessive disease means that both parents need to be carriers of MLD in order for it to be passed on to a child. MLD is a lysosomal storage disorder because of the buildup of sulfatides that happens when there is a lack of the ARSA enzyme. Sulfatides are a major part of the myelin sheath, which is the protective layer around nerves in the brain and spinal cord.
Listen to one mother share how this rare genetic disease impacted her family
MLD happens when changes in the ARSA gene slows or stops activity within the ARSA enzyme. This enzyme is responsible for the breakdown of sulfatides. This buildup of sulfatides happens in various tissue types:
This accumulation of sulfatides leads to demyelination (damage to the myelin sheath) and neurodegeneration (decline of the nervous system). This damages the nerves and causes a decline in brain function and motor issues, such as weakness and trouble walking. It is critical to diagnose MLD early before the disease progresses, as MLD is fatal if left untreated.
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. The average survival is 4.2 years for late infantile and 17.4 years for early juvenile patients.
ARSA, arylsulfatase A.
MLD is an autosomal recessive genetic disease, meaning it requires both parents to be carriers of the genetic mutation
Hear from one mother about why early diagnosis is so important
Patients with pre-symptomatic late infantile, pre-symptomatic early juvenile, and early symptomatic early juvenile MLD may have a treatment option.
