Diagnosis of an X-linked type 2 congenital stationary night blindness using electroretinography and CACNA1F sequencing

J Galindo-Bocero; S Macías-Franco; N García-González; C Valles-Antuña; I Hernando Acero; P Rozas-Reyes

doi:10.1016/j.oftal.2020.06.004

Diagnosis of an X-linked type 2 congenital stationary night blindness using electroretinography and CACNA1F sequencing

Arch Soc Esp Oftalmol (Engl Ed). 2020 Dec;95(12):607-610. doi: 10.1016/j.oftal.2020.06.004. Epub 2020 Jul 15.

[Article in English, Spanish]

Authors

J Galindo-Bocero¹, S Macías-Franco², N García-González³, C Valles-Antuña⁴, I Hernando Acero³, P Rozas-Reyes²

Affiliations

¹ Servicio de Oftalmología, Fundación Hospital de Jove, Gijón, Asturias, España. Electronic address: javiergalindobocero@hotmail.com.
² Servicio de Oftalmología, Hospital Universitario Central de Asturias, Oviedo, Asturias, España.
³ Unidad de Genética, Área de Gestión Clínica de Pediatría, Hospital Universitario Central de Asturias, Oviedo, Asturias, España.
⁴ Servicio de Neurofisiología Clínica, Hospital Universitario Central de Asturias, Oviedo, Asturias, España.

PMID: 32680768
DOI: 10.1016/j.oftal.2020.06.004

Abstract

A 4-year-old boy, with no history of relevance, presented with bilateral visual impairment, more so in scotopic conditions, and did not improve with optical correction. No significant funduscopic abnormalities were seen, leading to a suspicion of retinal dystrophy. Sequencing of the CACNA1F gene detected the c.3081C>A (p.Tyr1027Ter) mutation, which had occurred de novo in the patient's mother. This mutation, in the aforementioned clinical context, and with a compatible electronegative pattern, establishes the diagnosis of X-linked type 2 congenital stationary night blindness. Electrophysiology and genetic testing should be part of the diagnostic protocol for any unexplained loss of vision in children. The description, nomenclature and classification of hereditary retinal dystrophies based on their genotypic and electroretinograpic characteristics, avoids diagnostic errors due to their usual clinical and phenotypic overlap.

Keywords: CACNA1F; Ceguera nocturna estacionaria congénita; Congenital stationary night blindness; Electroretinography; Electrorretinografía; Nictalopía; Nyctalopia.