Leber's congenital amaurosis is a genetic disease that causes progressive retinal degeneration. Over the years it causes severe low vision, which can even turn into blindness. It usually occurs around the first 6 months of life and is the most frequent cause of hereditary childhood blindness. About 3 children out of every 100,000 new born suffer from it. One of the typical symptoms of the disease is nystagmus, which is the uncontrolled movement of the eyes.
Together with the progressive loss of sight, it is the first distinctive element of Leber's congenital amaurosis. To confirm the diagnosis, the doctor analyzes the electrical activity of the retina and the genetic analysis. The disease is associated with 15-20 altered genes, although in 5-10% of cases it is linked only to RPE65 mutations. For the disease to manifest itself, the child must inherit two altered copies of the gene. Otherwise, the disease does not manifest itself and the child simply remains a healthy carrier. If there have been cases in the family, it is therefore advisable to take precautions with the appropriate genetic tests.
There are several forms of Leber congenital amaurosis, depending on the genes affected by the anomalies. For most forms, there is no cure and no definitive therapeutic protocol. The only exception is the form that affects the RPE65 gene, for which there is a gene therapy available since 2017. The doctor administers a virus that carries a correct version of the genus in the eye. The therapy has proved effective, especially if inoculated in the early stages of the disease.