Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2003 Nov;87(11):1413-20.
doi: 10.1136/bjo.87.11.1413.

Genotype-phenotype correlation in British families with X linked congenital stationary night blindness

L E Allen  1 , I Zito, K Bradshaw, R J Patel, A C Bird, F Fitzke, J R Yates, D Trump, A J Hardcastle, A T Moore
Affiliations

Genotype-phenotype correlation in British families with X linked congenital stationary night blindness

L E Allen et al. Br J Ophthalmol. 2003 Nov.

Abstract

Aim: To correlate the phenotype of X linked congenital stationary night blindness (CSNBX) with genotype.

Methods: 11 CSNB families were diagnosed with the X linked form of the disease by clinical evaluation and mutation detection in either the NYX or CACNA1F gene. Phenotype of the CSNBX patients was defined by clinical examination, psychophysical, and standardised electrophysiological testing.

Results: Comprehensive mutation screening identified NYX gene mutations in eight families and CACNA1F gene mutations in three families. Electrophysiological and psychophysical evidence of a functioning but impaired rod system was present in subjects from each genotype group, although the responses tended to be more severely affected in subjects with NYX gene mutations. Scotopic oscillatory potentials were absent in all subjects with NYX gene mutations while subnormal OFF responses were specific to subjects with CACNA1F gene mutations.

Conclusions: NYX gene mutations were a more frequent cause of CSNBX than CACNA1F gene mutations in the 11 British families studied. As evidence of a functioning rod system was identified in the majority of subjects tested, the clinical phenotypes "complete" and "incomplete" do not correlate with genotype. Instead, electrophysiological indicators of inner retinal function, specifically the characteristics of scotopic oscillatory potentials, 30 Hz flicker and the OFF response, may prove more discriminatory.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Scotopic perimetry (representative examples). Mean threshold elevation to a blue stimulus was 3.5 log units in the NYX group and 2.0 log units in the CACNA1F group, whilst that to a red stimulus was 2.0 and 1.9 log units, respectively.
Figure 2
Figure 2
Dark adaptation on curves: blue stimulus, retinal location −9, 9. (A) Subjects with NYX gene mutations. (B) Subjects with CACNA1F gene mutations.
Figure 3
Figure 3
Comparison of ERG waveforms between genotype groups. (A) A scotopic b-wave response to an SF-2.6 log unit stimulus was recorded in both CSNBX genotype groups but was of lower amplitude in the NYX group. (B) Responses of CSNBX subjects to an SF stimulus in dark adapted conditions showed the typical “negative wave” response. The waveform in the NYX group was smooth and devoid of the wavelets of the oscillatory potentials seen in the normal and CACNA1F mutation group. (C) Scotopic oscillatory potentials (OP) were unrecordable in the NYX group and subnormal in the CACNA1F mutation group. (D) The 30 Hz photopic waveform was saw toothed in the NYX group, and biphasic and subnormal in the CACNA1F response. (E) The ON (b-wave) response was subnormal in all CSNBX subjects. The OFF (d-wave) response was normal in the NYX subjects and borderline subnormal in both CACNA1F subjects tested.
Figure 4
Figure 4
Scatter plots of scotopic ERG responses. (NYX gene mutation group = CSNB1, CACNA1F gene mutation group = CSNB2). (A) Plot of b-wave amplitude to scotopic stimulus (B) Plot of b-wave amplitude to SF stimulus. (C) Plot of maximal OP amplitude.
Figure 5
Figure 5
Scatter plots of photopic responses. (A) Plot of photopic b-wave amplitudes (ON response). (B) Plot of d-wave amplitudes (OFF response).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Schubert G, Bornscein H. Beitrag zur Analyse des menschlichen Elektroretinogramms. Ophthalmologica 1952;123:396–412. - PubMed
    1. Bornschein H, Vukovich B. Das Elektroretinogramm bei mangelhemeralopie. Albrecht von Graefes Arch klin Ophthalmol 1953;153:484–7. - PubMed
    1. Miyake Y, Yagasaki K, Horiguchi M, et al. Congenital stationary night blindness with negative electroretinogram. A new classification. Arch Ophthalmol 1986;104:1013–20. - PubMed
    1. Bech-Hansen NT, Boycott KM, Gratton KJ, et al. Localization of a gene for incomplete X-linked congenital stationary night blindness to the interval between DXS6849 and DXS8023 in Xp11.23. Hum Genet 1998;103:124–30. - PubMed
    1. Strom TM, Nyakatura G, Apfelstedt-Sylla E, et al. An L-type calcium-channel gene mutated in incomplete X-linked congenital stationary night blindness. Nat Genet 1998;19:260–3. - PubMed

Publication types

MeSH terms

Associated data