title: Clinical and molecular genetics of Leber's congenital amaurosis: a multicenter study of Italian patients.
abstract: OBJECTIVE
  To identify the molecular basis of Leber's congenital amaurosis (LCA) in a cohort of Italian patients and to perform genotype-phenotype analysis.
  
  
  METHODS
  DNA samples from 95 patients with LCA were analyzed by using a microarray chip containing disease-associated sequence variants in eight LCA genes. In addition, all patients in whom no mutations were identified by microarray were subjected to sequence analysis of the CEP290 gene. Patients with mutations identified underwent a detailed ophthalmic evaluation.
  
  
  RESULTS
  Disease-causing mutations were identified in 28% of patients, and twelve novel variants were identified. Mutations occurred more frequently in the RPE65 (8.4%), CRB1 (7.4%), and GUCY2D (5.2%) genes. Mutations in CEP290 were found in only 4.2% of the patients analyzed. Clinical assessment of patients carrying RPE65 or CRB1 mutations revealed the presence of retained visual capabilities in the first decade of life. RPE65 mutations were almost always associated with normal macular thickness, as assessed by optical coherence tomography (OCT), whereas CRB1 mutations were associated with reduced retinal thickness and a coarsely laminated retina. Fundus autofluorescence was mostly observed in patients with RPE65 and GUCY2D mutations and was not elicitable in patients carrying CRB1.
  
  
  CONCLUSIONS
  RPE65 gene mutations represented a significant cause of LCA in the Italian population, whereas GUCY2D and CEP290 mutations had a lower frequency than that found in other reports. This finding suggests that the genetic epidemiology of LCA in Italy is different from that reported in the United States and in northern European countries. Autofluorescence in patients with RPE65 mutations was more frequently associated with preserved retinal thickness, which suggests that these mutations are not associated with progression of retinal degeneration. Therefore, normal retinal thickness (identified with OCT) and fundus autofluorescence may be the means with which to identify patients with LCA who carry RPE65 mutations, which are expected to be a potential gene therapy target in the near future.
authors.affiliation: Department of Ophthalmology, Second University of Naples, Naples, Italy. franctes@tin.it
authors.forename: Francesca
authors.initials: F
authors.lastname: Simonelli
authors.forename: Carmela
authors.initials: C
authors.lastname: Ziviello
authors.forename: Francesco
authors.initials: F
authors.lastname: Testa
authors.forename: Settimio
authors.initials: S
authors.lastname: Rossi
authors.forename: Elisa
authors.initials: E
authors.lastname: Fazzi
authors.forename: Paolo Emilio
authors.initials: PE
authors.lastname: Bianchi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Fossarello
authors.forename: Sabrina
authors.initials: S
authors.lastname: Signorini
authors.forename: Chiara
authors.initials: C
authors.lastname: Bertone
authors.forename: Silvana
authors.initials: S
authors.lastname: Galantuomo
authors.forename: Francesco
authors.initials: F
authors.lastname: Brancati
authors.forename: Enza Maria
authors.initials: EM
authors.lastname: Valente
authors.forename: Alfredo
authors.initials: A
authors.lastname: Ciccodicola
authors.forename: Ernesto
authors.initials: E
authors.lastname: Rinaldi
authors.forename: Alberto
authors.initials: A
authors.lastname: Auricchio
authors.forename: Sandro
authors.initials: S
authors.lastname: Banfi
mesh_terms: D000951:Antigens, Neoplasm / Q000235:genetics*; D001766:Blindness / Q000453:epidemiology* / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D004252:DNA Mutational Analysis; D005136:Eye Proteins / Q000235:genetics*; D020869:Gene Expression Profiling; D005838:Genotype; D006162:Guanylate Cyclase / Q000235:genetics*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008565:Membrane Proteins / Q000235:genetics; D008967:Molecular Biology; D017720:Molecular Epidemiology; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D011956:Receptors, Cell Surface / Q000235:genetics*; D012162:Retinal Degeneration / Q000453:epidemiology / Q000235:genetics; D041623:Tomography, Optical Coherence; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase
chemical_list: D000951:Antigens, Neoplasm; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D005136:Eye Proteins; D006162:Guanylate Cyclase; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase; C448939:CRB1 protein, human; C493903:Cep290 protein, human; C110715:guanylate cyclase 1