Cone-rod dystrophy is a group of inherited eye disorders affecting the retina, the light-sensitive back layer of the eye. There are over 30 types of cone-rod dystrophy, and all are caused by various genetic mutations. The first signs and symptoms of cone-rod dystrophy often occur in childhood and include decreased sharpness of vision (visual acuity). Later symptoms include impaired color vision (dyschromatopsia), blind spots (scotomas) in the center of the visual field, and partial side (peripheral) vision loss. Night blindness is a later symptom, and most of those affected are legally blind by mid-adulthood. The gene mutations responsible for the condition are inherited in different patterns (autosomal recessive, autosomal dominant, or X-linked) depending on the specific mutation.
United States. National Institutes of Health. "Cone-Rod Dystrophy." <https://medlineplus.gov/genetics/condition/cone-rod-dystrophy/#causes>.