PCNA-related progressive neurodegenerative photosensitivity syndrome

PCNA-related progressive neurodegenerative photosensitivity syndrome is a rare neurodegenerative disease caused by homozygous mutations in the <i>PCNA</i> gene and characterized by neurodegeneration, postnatal growth retardation, prelingual sensorineural hearing loss, premature aging, ocular and cutaneous telangiectasia, learning difficulties, photophobia, and photosensitivity with evidence of predisposition to sun-induced malignancy. Progressive neurologic deterioration leads to gait disturbances, muscle weakness, speech and swallowing difficulties and progressive cognitive decline.