Stargardt disease
Stargardt Disease
It affects 1 in 10,000 people
It is caused by mutations in 1 gene (ABCA4)
It is the 1a cause of hereditary macular dystrophy in childhood
What is Stargardt disease?
Stargardt disease is a hereditary disorder that affects the central area of the retina: the macula. It is characterized by causing progressive degeneration of the cells of the retina, such as photoreceptors (cones and rods), which are responsible for converting light into nerve impulses that the brain transforms into images.
Despite being the leading cause of hereditary macular dystrophy in childhood, it is considered a rare or minority disease, as it is estimated that it affects only 1 in 10,000 people.
What causes it?
Stargardt disease is caused by mutations in the ABCA4 gene, which is responsible for other retinal dystrophies as well. It is usually transmitted through an autosomal recessive inheritance pattern, meaning that the parents of affected individuals do not have the disease but are carriers of the gene that causes it.
How can it be prevented?
Since it is a hereditary disease, it cannot be prevented. However, once diagnosed, patients are advised to avoid vitamin A-based supplements, as studies on animals have shown that vitamin A accelerates the progression of the disease. Patients are also recommended to protect themselves from intense light, especially sunlight, by using sunglasses with dark filters, as light exposure accelerates the evolution of the disease.
Symptoms
Stargardt disease typically manifests between childhood and the age of 30. The first symptom that sufferers usually experience is slow and progressive loss of central vision (visual acuity). It is, therefore, a disease that especially affects the ability to see fine detail and perform daily tasks such as reading and recognizing the faces of relatives.
As the disease progresses, vision loss becomes more severe, and in later stages, patients usually retain some degree of peripheral vision as well as approximately 10% of their visual acuity. There is also a relatively uncommon variant of Stargardt disease, caused by the mutation of the ABCA4 gene, known as fundus flavimaculatus (FF), whose evolution is slower but more severely affects peripheral vision.
Associated treatments
Currently, there is no cure for Stargardt disease. Because of this, the IMO Foundation is conducting research on the ABCA4 gene through the crowdfunded project Investigating a Gene in collaboration with the La Caixa Banking Foundation and ONCE. The goal is to study the mutations that cause the disease and other retinal dystrophies. To achieve this, the plan is to test new gene and cell therapies using cells previously donated by patients suffering from these diseases to restore vision or stop associated vision loss over the next decade.
Gene therapies could be used on patients suffering from the earliest stages of the disease. These therapies would involve introducing healthy copies of the mutated gene into patients, which have been artificially created in a laboratory, to perform the function of the gene.
For more advanced cases, gene therapies may not be effective because the disease causes irreparable damage to the retinal cells as it progresses. It is envisioned that these patients may undergo stem cell transplantation (cell therapy) to replace the damaged tissue.