title: Evaluation of Italian patients with leber congenital amaurosis due to AIPL1 mutations highlights the potential applicability of gene therapy.
abstract: OBJECTIVE
  To evaluate the suitability of gene delivery-based approaches as potential treatment of Leber congenital amaurosis 4 (LCA4) due to AIPL1 mutations.
  
  
  METHODS
  Genomic DNA from patients was analyzed using a microarray chip and direct sequencing. A detailed clinical evaluation including fundus autofluorescence (FAF) and optical coherence tomography (OCT) was performed in patients with AIPL1 mutations. Aipl1 null mice and porcine eyes were subretinally injected with adeno-associated viral (AAV) vectors harboring the human AIPL1 coding sequence.
  
  
  RESULTS
  We identified 10 LCA4 patients with mutations in AIPL1. The p.W278X sequence variation was the one most frequently found. Clinical assessment revealed common features including diffuse retinal dystrophies and maculopathy. However, optical coherence tomography showed partially retained photoreceptors in extramacular regions at all ages. The fundus autofluorescence was elicitable at the posterior pole and absent in the fovea. AAV-mediated gene transfer in Aipl1 -/- mice was associated with restoration of AIPL1 and βPDE expression in photoreceptors and protection from degeneration. Administration of a clinically relevant dose of AAV2/8-AIPL1 to the preclinical large porcine retina resulted in high level of AIPL1 photoreceptor expression in the absence of toxicity.
  
  
  CONCLUSIONS
  Using advanced imaging diagnostics we showed that maculopathy is a main feature of LCA4. We identified retinal areas at the posterior pole with surviving photoreceptors present even in adult LCA4 patients, which could be the target of gene therapy. The possible use of gene therapy for LCA4 is additionally supported by the protection from photoreceptor degeneration observed in Aipl 1-/- mice and by the high levels of photoreceptor transduction in the absence of toxicity observed after AAV2/8 delivery to the large porcine retina.
authors.affiliation: Department of Ophthalmology, Seconda Università degli Studi di Napoli, Naples, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Testa
authors.forename: Enrico Maria
authors.initials: EM
authors.lastname: Surace
authors.forename: Settimio
authors.initials: S
authors.lastname: Rossi
authors.forename: Elena
authors.initials: E
authors.lastname: Marrocco
authors.forename: Annagiusi
authors.initials: A
authors.lastname: Gargiulo
authors.forename: Valentina
authors.initials: V
authors.lastname: Di Iorio
authors.forename: Carmela
authors.initials: C
authors.lastname: Ziviello
authors.forename: Anna
authors.initials: A
authors.lastname: Nesti
authors.forename: Simona
authors.initials: S
authors.lastname: Fecarotta
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Bacci
authors.forename: Massimo
authors.initials: M
authors.lastname: Giunti
authors.forename: Michele
authors.initials: M
authors.lastname: Della Corte
authors.forename: Sandro
authors.initials: S
authors.lastname: Banfi
authors.forename: Alberto
authors.initials: A
authors.lastname: Auricchio
authors.forename: Francesca
authors.initials: F
authors.lastname: Simonelli
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004195:Disease Models, Animal; D004596:Electroretinography; D005136:Eye Proteins / Q000235:genetics*; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006801:Humans; D007558:Italy; D057130:Leber Congenital Amaurosis / Q000235:genetics / Q000473:pathology / Q000628:therapy; D051379:Mice; D018345:Mice, Knockout; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D034421:Sus scrofa; D041623:Tomography, Optical Coherence; D055815:Young Adult
chemical_list: C403625:AIPL1 protein, human; D048868:Adaptor Proteins, Signal Transducing; C498604:Aipl1 protein, mouse; D002352:Carrier Proteins; D005136:Eye Proteins