Stargardt disease

Stargardt disease is the most common inherited single-gene retinal disease. In terms of the first description of the disease, it follows an autosomal recessive inheritance pattern, which has been later linked to bi-allelic ABCA4 gene variants (STGD1).

However, there are Stargardt-like diseases with mimicking phenotypes that are referred to as STGD3 and STGD4, and have an autosomal dominant inheritance due to defects with ELOVL4 or PROM1 genes, respectively. It is characterized by macular degeneration that begins in childhood, adolescence or adulthood, resulting in progressive loss of vision.

Signs and symptoms

The presentation usually occurs in childhood or adolescence, though there is no upper age limit for presentation and late-onset is possible. The main symptom is loss of visual acuity, uncorrectable with glasses. This manifests as the lack of the ability to see fine details when reading or viewing distant objects. Symptoms typically develop before age 20 (median age of onset: ~17 years old), and include: wavy vision, blind spots, blurriness, loss of depth perception, sensitivity to glare, impaired colour vision, and difficulty adapting to dim lighting (delayed dark adaptation). There is a wide variation between individuals in the symptoms experienced as well as the rate of deterioration in vision. Vision loss can be attributed to the buildup of by-products of vitamin A in photoreceptor cells and peripheral vision is usually less affected than fine, central (foveal) vision.