Table 1

Overview of the genes associated with LCA/EOSRD, the encoded proteins, their proposed function(s) and estimated frequency.

Locus nameCausative
gene
ProteinProtein function(s)Approximate frequency
LCA 1GUCY2DGuanylate cyclase-1Phototransduction10%–20%
LCA 2RPE65Retinoid isomeraseRetinoid cycle5%–10%
LCA 3SPATA7Spermatogenesis-associated protein 7Photoreceptor ciliary transport3%
LCA 4AIPL1Aryl-hydrocarbon-interacting-protein-like 1Phototransduction/protein biosynthesis<5%
LCA 5LCA5LibercilinPhotoreceptor ciliary transport1%–2%
LCA 6RPGRIP1Retinitis pigmentosa GTPase regulator-interacting protein 1Photoreceptor ciliary transport5%
LCA 7CRXCone–rod homeoboxPhotoreceptor morphogenesis1%
LCA 8CRB1Crumbs homologue 1Photoreceptor morphogenesis10%
LCA 9NMNAT1Nicotinamide nucleotide adenyltransferase1Coenzyme NAD biosynthesisUnknown
LCA 10CEP290Centrosomal protein 290 kDAPhotoreceptor ciliary transport15%–20%
LCA 11IMPDH1Inosine 5'—monophosphate dehydrogenase 1Guanine synthesis5%
LCA 12RD3Protein RD3Protein trafficking<1%
LCA 13RDH12Retinol dehydrogenase 12Retinoid cycle10%
LCA 14LRATLecithin:retinol acyl transferaseRetinoid cycle<1%
LCA 15TULP1Tubby-like proteinPhotoreceptor ciliary transport<1%
LCA 16KCNJ13Kir7 inwardly rectifying potassium channelPhototransductionUnknown
LCA 17GDF6Growth differentiation factor 6Photoreceptor morphogenesisUnknown
OTX2Orthodenticle homeobox 2 proteinPhotoreceptor differentiationUnknown
CABP4Calcium-binding protein 4PhototransductionUnknown
CLUAP1Clusterin associated protein 1Photoreceptor ciliary transportUnknown
IQCB1IQ motif containing B1 proteinPhotoreceptor ciliary transportUnknown
DTHD1Death-domain containing protein 1UnknownUnknown
IFT140Intraflagellar transport 140 chlamydomonas homologue proteinPhotoreceptor ciliary transportUnknown
ALMS1ALMS ProteinPhotoreceptor ciliary transportUnknown
PRPH2PerpherinPhotoreceptor outer segment structure/stabilisationUnknown
  • Genes more frequently associated with LCA have been shaded blue, while those associated with EOSRD have been shaded green. Others have shown no clear predilection.

  • EOSRD, early-onset severe retinal dystrophy; LCA, Leber congenital amaurosis.