Access this Article

Abstract

Purpose: The 2 most common causative genes for achromatopsia (ACHM) are CNGA3 and CNGB3; other genes including GNAT2 account for only a small portion of ACHM cases. The cone mosaics in eyes with CNGA3 and CNGB3 variants are severely disrupted; the cone mosaics in patients with GNAT2-associated ACHM; however, have been reported to show a contiguous pattern in adaptive optics (AO) retinal images. The purpose of this study was to analyze the cone mosaic of another case of GNAT2-associated ACHM. Patient and methods: The patient was a 17-year-old Japanese boy. Comprehensive ocular examinations including fundus photography, electroretinography (ERGs), optical coherence tomography (OCT), and whole-exome analysis were performed. The cone mosaic was recorded with a flood-illuminated AO fundus camera, and the cone density was compared with those of 10 normal control eyes. Results: The patient had the typical phenotype of ACHM, and a novel homozygous variant, c.730_743del, in GNAT2 was identified. The fundus did not show any specific abnormalities, and the OCT images showed the presence of the ellipsoid zone. The AO fundus image showed a clearly defined cone mosaic around the fovea. The cone density at 500 μm from the fovea was reduced by 15–30 % as compared with those of the normal eyes. Conclusions: This is the first description of a Japanese patient with ACHM with a novel GNAT2 variant. The eyes of this patient had a preserved cone structure with loss of function.

Journal

  • Japanese journal of ophthalmology : the official international journal of the Japanese Ophthalmological Society

    Japanese journal of ophthalmology : the official international journal of the Japanese Ophthalmological Society 61(1), 92-98, 2017-01

    Springer

Codes

  • NII Article ID (NAID)
    120006220426
  • NII NACSIS-CAT ID (NCID)
    AA00691177
  • Text Lang
    ENG
  • Article Type
    journal article
  • ISSN
    0021-5155
  • NDL Article ID
    027850923
  • NDL Call No.
    Z53-D450
  • Data Source
    NDL  IR 
Page Top