NRL and Leber congenital amaurosis: In one interesting simplex case compound heterozygous frameshifts in the NRL gene, (NM_006177.3:c.16delA,p.Ser6fs) and (NM_006177.3:c.386delC,p.Ala129fs), were found in a patient with atypical LCA marked by unusually good retention of visual acuity despite the presence of typical LCA features such as congenital nystagmus, extinguished ERG and onset of visual symptoms at a very young age.