[From gene to disease; Leber congenital amaurosis (LCA)].

LCA is a severe retinal dystrophy characterised by an onset of symptoms before the age of 6 months, visual acuity below 201/400, searching nystagmus, sluggish pupillary reactions and no detectable responses on electrography. The visual fields are usually not measurable. LCA is genetically heterogeneous and is usually inherited in an autosomal recessive fashion. Seven genes have been reported to be mutated in LCA patients (AIPL1, CRB1, CRX, GUCY2D, RDH12, RPE65 and RPGRIP1). Each gene is responsible for a fraction of LCA patients. Mutations in these seven genes are estimated to underlie approximately 40-50% of LCA cases. Molecular genetic research is crucial to unravel the remaining genetic causes of this disabling disease.