A type of achromatopsia previously identified as ACHM1 was later found to be the same as ACHM3 caused by cyclic nucleotide-gated channel beta-3 (CNGB3) gene (MIM 605080).8 Among other genes are included cyclic nucleotide-gated channel alpha-3 (CNGA3; MIM 600053) causing ACHM29, Guanine nucleotide-binding protein G subunit [alpha]-2 (GNAT2; MIM 139340) causing ACHM4, 10 phosphodiesterase 6C (PDE6C; MIM 613093) causing ACHM5, 11 cone inhibitory phosphodiesterase 6H (PDE6H; MIM 601190) causing ACHM612 and activating transcription factor 6 (ATF6; MIM 605537) causing ACHM7.13 The current study was planned to report two Pakistani families that were initially evaluated as having nystagmus phenotype.
Homozygosity mapping reveals PDE6C mutations in patients with early-onset cone photoreceptor disorders.
Moreover, C3-knockout mice demonstrated higher expression levels of genes involved in maintaining the physiological function of the neural retina: abhydrolase domain containing 14A (Abhd14a); complexin 4 (Cplx4); cGMP specific-phosphodiesterase 6C (Pde6c); neurofilament (Nefl); aldehyde dehydrogenase family 1, subfamily A1 (Aldh1a1); retinitis pigmentosa GTPase regulator interacting protein-1 (Rpgrip1); and regulator of G protein signaling 9 binding protein (Rgs9bp).
These processes are represented in our study by several upregulated genes: Gucy2f, Ppt1, Bbs2, Crb1, Gabrr2, Rgs9bp, Rpgrip1, and Pde6c, which are essential for photoreceptor-based light-dependent signal transformation and transduction.
Phosphodiesterase 6C, encoded by our predicted gene PDE6C, has been confirmed to contribute to pyrimidine metabolism and phototransduction [129, 130].
Dangel et al., "A homologous genetic basis of the murine cpfl1 mutant and human achromatopsia linked to mutations in the PDE6C gene," Proceedings of the National Academy of Sciences of the United States of America, vol.
Condition Name Gene Location Inheritance Oculocutaneous OCA1 TYR 11q14.3 AR albinism OCA2 15q12--q13 AR OCA3 TYRP1 9p23 AR OCA4 MATP 5p13.2 AR Ocular albinism OA1 GPR143 Xp22.2 XL Aniridia AN2 PAX6 11p13 AD CSNB CSNB1 NYX Xp11.4 XL CSNB CSNB2 CACNA1F Xp11.23 XL Rod monochromacy ACHM2 CNGA3 2q11.2 AR Cone dystrophy 4 COD4 PDE6C 10q23.33 AR Blue cone monochromacy COD5 OPN1L/MW Xq28 XL Optic nerve hypoplasia PAX6 11p13 AD (septo-optic dysplasia) HESX1 3p14.3 AR Corneal opacity PAX6 11p13 AD PITX2 4q25 AD FOXC1 6p25.3 AD Congenital cataract PAX6 11p13 AD Leber's congenital LCA1- Various Various AD/R amaurosis 15 Idiopathic NYS1 FRMD7 Xq26.2 XL NYS5 Xp11.4 XL NYS2 6p12 AD NYS3 7p11.2 AD 18q23 AD Figure 3 Some associations of infantile nystagmus, from Lorenz and Gampe.