What Your Test Results Mean:

Carriers typically show no symptoms of Salla disease; however, carriers are at an increased risk of having a child with Salla disease. Risk for the current or future pregnancies is dependent on your partner’s carrier status. Carrier testing of your partner is recommended in addition to consultation with a genetic counselor.

Disease Explained:

Salla disease is an inherited condition that affects the cell’s ability to export free sialic acid from the lysosomes, causing severe impairment of the nervous system. Babies with Salla disease usually have poor muscle tone and progressive neurological problems during the first year of life. Signs and symptoms of Salla disease include intellectual disability and developmental delay, seizures, problems with movement and balance, and muscle spasticity. Motor and mental skills grad- ually decline in these individuals, and though most adults with the disease live normal lifespans, they are profoundly disabled. In more rare and severe cases, the disease progresses more quickly and may lead to decreased lifespan.

How the Genetics Works:

Salla disease is an autosomal recessive disorder caused by pathogenic variants in the SLC17A5 gene. In general, individuals have two copies of the SLC17A5 gene. Carriers of Salla disease have a single variant in one copy of the SLC17A5 gene while individuals with Salla disease have variants in both copies of their genes, one inherited from each parent. Risk for two carriers to have a child with the disorder is 25%.