MGT005 is a natural history study to collect longitudinal prospective data from patients with Leber Congenital Amaurosis associated with defects in RPE65.

Leber Congenital Amaurosis (LCA) is a diagnosis for a group of severe, autosomal recessively inherited rod - cone dystrophies that typically result in complete visual loss in the third or fourth decade of life. One form, LCA2, is caused by a mutation in the gene encoding RPE56, an RPE-specific 65-kDa isomerase. Non-functional RPE65 results in photoreceptor cells that are unable to respond to light resulting in these patients being visually impaired.

In preparation for human clinical trials, a detailed prospective phenotypic study will be undertaken to investigate the natural history of RPE65-LCA. Such a study will help identify suitable patients for therapeutic intervention. Furthermore through greater phenotyping an optimal window for intervention and specific parameters to help quantify effect and identify clinical end points may have been ascertained .

Inclusion Criteria:

• Patients with RPE65 associated retinal dystrophy
• Minimum subject age of 3 years
• Able to give consent/parent or guardian able to give consent

Exclusion Criteria:

• Patients unable or unwilling to undertake consent or clinical testing
• Have received a gene therapy treatment in both eyes

Patients with RPE65-LCA condition