What Your Test Results Mean:

Carriers typically show no symptoms of NCL; however, carriers are at an increased risk of having a child with NCL. 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:

CLN5-related NCL is an inherited lysosomal storage disorder that impairs the cell’s ability to break down proteins and primarily affects the nervous system. Symptoms typically begin with vision loss followed by progressive motor deterioration, developmental regression, and increasing intellectual disability. Lifespan is shortened but some individuals live to early adulthood. Clinical trials surrounding stem cell therapy and other treatments are currently underway.

How the Genetics Works:

NCL can be explained by pathogenic variants in one of thirteen genes. CLN5-related NCL is an autosomal recessive disorder caused by variants in the CLN5 gene. In general, individuals have two copies of the CLN5 gene. Carriers of NCL have a single variant in one copy of the CLN5 gene while individuals with NCL 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%.