Table 1

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

Locus nameCausative
ProteinProtein function(s)Approximate frequency
LCA 1 GUCY2DGuanylate cyclase-1Phototransduction10%–20%
LCA 2 RPE65Retinoid isomeraseRetinoid cycle5%–10%
LCA 3 SPATA7 Spermatogenesis-associated protein 7Photoreceptor ciliary transport3%
LCA 4 AIPL1Aryl-hydrocarbon-interacting-protein-like 1Phototransduction/protein biosynthesis<5%
LCA 5 LCA5 LibercilinPhotoreceptor ciliary transport1%–2%
LCA 6 RPGRIP1 Retinitis pigmentosa GTPase regulator-interacting protein 1Photoreceptor ciliary transport5%
LCA 7 CRX Cone–rod homeoboxPhotoreceptor morphogenesis1%
LCA 8 CRB1Crumbs homologue 1Photoreceptor morphogenesis10%
LCA 9 NMNAT1Nicotinamide nucleotide adenyltransferase1Coenzyme NAD biosynthesisUnknown
LCA 10 CEP290 Centrosomal protein 290 kDAPhotoreceptor ciliary transport15%–20%
LCA 11 IMPDH1 Inosine 5’—monophosphate dehydrogenase 1Guanine synthesis5%
LCA 12 RD3 Protein RD3Protein trafficking<1%
LCA 13 RDH12Retinol dehydrogenase 12Retinoid cycle10%
LCA 14 LRATLecithin:retinol acyl transferaseRetinoid cycle<1%
LCA 15 TULP1 Tubby-like proteinPhotoreceptor ciliary transport<1%
LCA 16 KCNJ13 Kir7 inwardly rectifying potassium channelPhototransductionUnknown
LCA 17 GDF6 Growth differentiation factor 6Photoreceptor morphogenesisUnknown
OTX2 Orthodenticle homeobox 2 proteinPhotoreceptor differentiationUnknown
CABP4 Calcium-binding protein 4PhototransductionUnknown
CLUAP1 Clusterin associated protein 1Photoreceptor ciliary transportUnknown
IQCB1 IQ motif containing B1 proteinPhotoreceptor ciliary transportUnknown
DTHD1 Death-domain containing protein 1UnknownUnknown
IFT140 Intraflagellar transport 140 chlamydomonas homologue proteinPhotoreceptor ciliary transportUnknown
ALMS1 ALMS ProteinPhotoreceptor ciliary transportUnknown
PRPH2 PerpherinPhotoreceptor outer segment structure/stabilisationUnknown
  • *Genes associated with EOSRD.

  • †Genes more frequently associated with LCA.

  • Other genes have shown no clear predilection.

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