Leukodystrophies affect the growth and/or development of myelin, the fatty covering that acts as an insulator around nerve fibers throughout the central and peripheral nervous systems.

[2] Like many other genetic disorders that affect lipid metabolism, there are several forms of MLD, which are late infantile, juvenile, and adult.

[4] Without this enzyme, sulfatides build up in many tissues of the body, eventually destroying the myelin sheath of the nervous system.

[4] The enzyme that is present is not "enabled" to a normal level of efficiency and can't break down the sulfatides which results in all of the same MLD symptoms and progression.

It has been suggested that lysosulfatide, sulfatide which has had its acyl group removed, plays a role because of its cytotoxic properties in vitro.

With the current diagnostic tests, Pseudo-deficiency reports as low enzyme levels but sulfatide is processed normally so MLD symptoms do not exist.

Positive results led to MLD being included in the ScreenPlus identified baby research project in New York state, which is currently scheduled to launch in Q1'2021.

[citation needed] There is currently no approved treatment for MLD in symptomatic late infantile patients or for juvenile and adult-onset with advanced symptoms.

[citation needed]Pre-symptomatic late infantile MLD patients, as well as those with juvenile or adult MLD that are either presymptomatic or displaying mild symptoms, can consider bone marrow transplantation (including stem cell transplantation), which may slow down the progression of the disease in the central nervous system.

[citation needed] In 2020 the European Medical Agency approved the cell therapy drug atidarsagene autotemcel (Libmeldy) for the treatment of infantile and juvenile forms of metachromatic leukodystrophy in Europe.

[12] Presymptomatic patients can be cured with one treatment of atidarsagene autotemcel, which is a type of advanced medicine called a ‘gene therapy’.