Leber's congenital amaurosis
Leber's congenital amaurosis (LCA) is a rare inherited eye disease that appears at birth or in the first few months of life, and affects around 1 in 80,000 of the population. One form of LCA became well known in the scientific community following its successful treatment with gene therapy in 2008.
Signs and symptoms
The term congenital refers to a condition present from birth (not acquired) and amaurosis refers to a loss of vision not associated with a lesion. However, beyond these general descriptions, the presentation of LCA can vary, because it is associated with multiple genes.
Genetic tests and related research are currently being performed at Centogene AG in Rostock, Germany; University of Iowa John and Marcia Carver Nonprofit Genetic Testing Laboratory in Iowa City, IA; GENESIS Center for Medical Genetics in Poznan, Poland; Baylor College of Medicine Miraca Genetics Laboratories in Houston, TX; Asper Biotech in Tartu, Estonia; CGC Genetics in Porto, Portugal; CEN4GEN Institute for Genomics and Molecular Diagnostics in Edmonton, Canada; and Reference Laboratory Genetics - Barcelona, Spain.
One form of LCA, patients with LCA2 bearing a mutation in the RPE65 gene, has been successfully treated by gene therapy in clinical trials. The results of three early clinical trials were published in 2008 demonstrating the safety and efficacy of adeno-associated virus to restore vision in LCA patients. In all three clinical trials, patients recovered functional vision without apparent side-effects. These studies, which used adeno-associated virus, have spawned a number of new studies investigating gene therapy for human retinal disease.
The results of a phase 1 trial conducted, by the University of Pennsylvania and Children’s Hospital of Philadelphia and published in 2009, showed sustained improvement in 12 subjects (ages 8 to 44) with RPE65-associated LCA after treatment with AAV2-hRPE65v2, a gene replacement therapy. Early intervention was associated with better results. In that study patients were excluded based on the presence of particular antibodies to the vector AAV2 and treatment was only administered to one eye as a precaution. A 2010 study testing the effect of administration of AAV2-hRPE65v2 in both eyes in animals with antibodies present suggested that immune responses may not complicate use of the treatment in both eyes.
In Popular Culture
- In the episode The Blackout in the Blizzard (season 6, episode 16) of the television drama Bones, Dr. Jack Hodgins and his pregnant wife Angela Montenegro, who is an LCA carrier, have to wait during a citywide blackout for Hodgins's genetic test results, to see if he is also an LCA carrier. He does indeed turn out to be a carrier, giving their unborn child a 25% chance of having LCA.
- In the television series ER (season 14, episode 12 named "Believe the Unseen") Dr. Abby Lockhart diagnoses a young foster girl with Leber's congenital amaurosis. The girl to this point hid her condition from her foster families. The episode contains some information about symptoms, clinical diagnosis and mentions gene replacement therapy and clinical trials as hope for help in managing the condition.
- In the Korean drama The King of Dramas (episode 16, "In Search Of Lost Time") Anthony Kim, played by Kim Myung-min, is diagnosed with Leber's congenital amaurosis, the same disease that made his mother blind.
- 4 year old Gavin who suffers from a form of LCA was made famous in 2013 by a YouTube video showing him using his white cane for the first time to navigate down a curb.
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- (May 2008) "Safety and efficacy of gene transfer for Leber's congenital amaurosis". N. Engl. J. Med. 358 (21): 2240–8. doi:10.1056/NEJMoa0802315. PMID 18441370.
- (March 2010) "Gene therapy for Leber's congenital amaurosis is safe and effective through 1.5 years after vector administration". Mol. Ther. 18 (3): 643–50. doi:10.1038/mt.2009.277. PMID 19953081.
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- Foundation for Retinal Research
- GeneReview/NIH/UW entry on Leber Congenital Amaurosis
- Leber's Congenital Amaurosis FAQ from WonderBaby.org
- Leber's Congenital Amaurosis Treated with Gene Therapy
- Psychology Dictionary