Night Blindness, Congenital Stationary, Type 1f

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Retrieved

2019-09-22

Source

Omim

Trials

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Genes

RHO, GRM6, TRPM1, GNAT1, LRIT3, SLC24A1, PDE6B, GPR179, SAG, CACNA1F, NYX, CABP4, GNB3, CACNA2D4, GRK1, RDH5, RBP4, TRAPPC9, USH2A, ABCA4, RPGR, RBP3, FGFR2, ERG, GRK7, RPE65, USP11, SOCS2, BBS1, GNAZ

Drugs

Adeno-associated virus serotype 8 containing the human RdCVF sequence and the human RdCVFL sequence, Combination of three adeno-associated viral vectors of serotype 8 containing the 5'-, the body- and the 3'- coding sequences of human CEP290 fused to inteins

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A number sign (#) is used with this entry because of evidence that complete congenital stationary night blindness type 1F (CSNB1F) is is caused by compound heterozygous mutation in the LRIT3 gene (615004) on chromosome 4q25.

For a general phenotypic description and a discussion of genetic heterogeneity of congenital stationary night blindness, see CSNB1A (310500).

Clinical Features

Zeitz et al. (2013) studied a 45-year-old woman who from childhood had visual blurring and night-vision disturbances. At age 4 years, she had surgery for strabismus of the right eye and was prescribed glasses for myopia. At age 25 years, she underwent laser treatment for retinal tears. At age 45 years, she underwent electroretinography (ERG) for the first time, which revealed features of complete congenital stationary night blindness: undetectable responses to a dim flash under dark-adapted conditions, a negative waveform in the mixed rod-cone response in the dark-adapted state, and an unusual square-shaped a-wave in the cone ERG. Visual acuities were 20/80 in the right eye and 20/30 in the left eye, with normal eye pressures and a funduscopic appearance consistent with myopia. Zeitz et al. (2013) also examined a 9-year-old girl who was diagnosed with high myopia at age 2 years, at which time prominent night blindness was also noted; later, decreased visual acuity was found. She had no photoaversion or loss of visual fields. At age 9 years, visual acuities were 20/40 and 20/50 in the right and left eyes, respectively, and funduscopy was consistent with myopia with a tilted optic disc. Fundus autofluorescence and OCT-3 scan were normal. Light sensitivity was moderately decreased over the entire visual field. She had an electronegative ERG mixed rod-cone response in the dark-adapted state, with moderately reduced cone 30-Hz flicker responses, an atypical waveform in the light-adapted state, and no ERG responses to dim stimuli in the dark-adapted state; the ERG findings were consistent with a diagnosis of complete CSNB.

Molecular Genetics

In a 45-year-old woman with a diagnosis of complete CSNB who was negative for mutation in known CSNB genes, Zeitz et al. (2013) performed whole-exome sequencing and identified compound heterozygosity for a missense and a nonsense mutation in the LRIT3 gene (615004.0001 and 615004.0002). Sanger sequencing of LRIT3 in an additional 89 individuals with CSNB revealed a 9-year-old girl who was compound heterozygous for a nonsense mutation and a 2-bp deletion (615004.0003-615004.0004). The mutations segregated with disease in both families and were not found in control chromosomes.