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Updated: Jun 12, 2025
A Phenotyping Regimen for Genetically Modified Mice Used to Study Genes Implicated in Human Diseases of Aging
Published on: July 14, 2016
GENETIC ETIOLOGY AND CLINICAL FEATURES OF ACHROMATOPSIA IN JAPAN
Taiga Inooka1, Takaaki Hayashi2, Kazushige Tsunoda3
1Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Purpose:
To ascertain the characteristics of achromatopsia (ACHM) in Japan by analyzing the genetic and phenotypic features of patients with ACHM.
Methods:
The medical records of 52 patients from 47 Japanese families who were clinically diagnosed with ACHM were reviewed in this retrospective observational study.
Results:
Thirty-six causative variants of ACHM were identified in 26 families via whole-exome sequencing: PDE6C (12 families), CNGA3 (10 families), CNGB3 (two families), and GNAT2 (two families). However, none of the 6 causative variants that are known to cause ACHM, or the 275 other genes listed in RetNet, were observed in 19 families. A significant trend toward older age and worsening of ellipsoid zone disruption on optical coherence tomography images was observed (P < 0.01). Progressive ellipsoid zone disruptions were observed in 13 eyes of seven patients during the follow-up visits. These patients harbored one or more variants in PDE6C.
Conclusion:
The ACHM phenotype observed in this study was similar to those observed in previous reports; however, the causative gene variants differed from those in Europe. The low identification ratio of causative genes in whole-exome sequencing suggests the presence of unique hotspots in Japanese patients with ACHM that were not detectable via ordinal whole-exome sequencing.
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