Abnormal cone ERGs in a family with congenital nystagmus and photophobia harboring a p.X423Lfs mutation in the PAX6 gene.

Purpose: To describe the clinical, functional, and genetic findings in a young Caucasian girl and her father, in whom a mutation of the PAX6 gene was identified.

Methods: Detailed histories, eye examinations, and flash electroretinograms (ERGs) were acquired from both patients, and molecular genetic diagnostic testing was performed. Both patients were followed over a 2-year period.