Optic neuropathy

Gene: CCT3

Green List (high evidence)

Comment on list classification: There are 3 unrelated individuals reported with heterozygous CCT3 variants and visual impairment stemming from optic nerve atrophy and hypomyelination - tagged for promotion to Green at the next update.

Created: 20 Feb 2026, 10:14 a.m. | Last Modified: 20 Feb 2026, 10:14 a.m.

Panel Version: 5.46

PMID: 39480921 Kraft et al., 2024
4 individuals aged 2-8 yo, reported with heterozygous CCT3 variants (frameshift, missense, stop gain - all 4 confirmed de novo). Patients presented with ID, seizures, visual impairment and brain malformations. Phenotype spectrum: DD/ID (4/4, severe), seizures (2/4), visual impairment (3/4), pyramidal/cerebellar signs (4/4), brain MRI abnormalities (3/3). MRI findings included cerebellar atrophy, hypomyelination of white matter, hypoplasia of corpus callosum, and atrophy of optic tract, chiasm and optic nerves.

CCT3 is associated with Neurodevelopmental disorder with speech or visual impairment and brain hypomyelination, OMIM:621034 (OMIM accessed 20th Feb 2026).
Sources: Literature

Created: 20 Feb 2026, 10:12 a.m.

Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted

Phenotypes
Neurodevelopmental disorder with speech or visual impairment and brain hypomyelination, OMIM:621034; neurodevelopmental disorder with speech or visual impairment and brain hypomyelination, MONDO:0976125

Publications

• 39480921