ALLELIC VARIANTS (2 Selected Examples):
Table View
.0001CONE-ROD DYSTROPHY
UNC119, LYS57TER [dbSNP:rs267607166] ClinVar
In a Japanese woman with late-onset cone-rod dystrophy, Kobayashi et al. (2000) identified an A-to-T transversion in exon 1 of the UNC119 gene, resulting in a lys57-to-ter (K57X) substitution. The mutation was not identified in 100 control individuals. From age 40, the patient had reported symptoms of poor night vision, defective color vision, and light sensitivity. At age 57 years, she had reduced visual acuity (20/40), myopia, macular atrophy, pericentral ring scotomas, and an electroretinogram (ERG) consistent with cone-rod dystrophy. A 36-year-old daughter carrying the same mutation had a history of seeing bright flashes from a young age, as was also experienced by her mother, but did not yet demonstrate clear-cut ERG abnormalities. Transgenic mice carrying the K57X mutation showed a progressive decrease in the ERG b-wave (independent of the photoreceptor's ability to generate a c-wave), leading to retinal degeneration with prominent degeneration of the synapses