No disease is too rare to fight

Salla is a genetic disease affecting children

FSASD is caused by the accumulation of sialic acid in neurons, leading to serious and irreversible damage to the central nervous system.  Parents first become aware of the disease as important developmental milestones are missed within the first 12 months.   Some patients learn to walk but involuntary spasms (termed spasticity) and muscle weakness result in most patients being wheelchair bound by teenage years.  

Symptoms become progressively worse as patients grow older.  A lifetime of caregiver support is required placing a significant burden on affected families.

STAR child Ben in a gymnastic hall balancing while being helped by two caregivers.

FSASD is caused by genetic mutations in the sialic acid transporter SLC17A5

SLC17A5 is a tiny pore in the membrane that acts as a gate to let sialic acid flow out of the lysosome so it can be recycled elsewhere in the cell.  Mutations in SLC17A5 produce dysfunctional pores that transport sialic acid at much reduced levels.

Cross section of the SLC17A5 membrane.
The Science

How mutations in SLC17A5 cause disease

Explanatory 3D illustration of a normal lyosome.

Normal cells

SLC17A5 pore functioning correctly. Sialic acid properly recycled within the cell leading to healthy neurons

Explanatory 3D illustration of an affected lyosome.

FSASD affected cells 

SLC17A5 pore malfunctioning or not present on lysosome. Sialic acid accumulates in lysosome at 10 – 100 fold normal levels leading to lysosome dysfunction and widespread neuronal damage.

The Impact

FSASD is a rare and highly under diagnosed condition

300 patients reported

STAR is building a global community to bridge support families and uncover undiagnosed patients

23,000 worldwide prevalence

Significantly underdiagnosed due to awareness of the disease and availability of reliable sialic acid lab testing

Predominant gene mutation

Unlike many rare diseases, approximately 75% of patients have the same R39C mutation, which could lead to streamlined medicine development

Learn about Salla Disease research

FSASD Consortium member, Marya Sabir, discusses the role that SLC17A5 mutations play in Salla Disease and as a risk factor in more prevalent diseases such as Parkinson's.  She discusses her ground breaking work on the development of an animal model that mimics the human disease, a powerful tool for drug discovery.