a newborn has been found to be very photophobic, and his skin burns even with minimal exposure to sunlight, eventually forming skin blisters. neither parent exhibits this trait, although both are prone to burning when in the sun for a short period of time. as the child grows, he is found to be at average height and weight for his age, and is progressing normally along the developmental guidelines. he is, however, kept inside at all times, and is carefully wrapped if he has to leave the house. fibroblast cells isolated from this child are grown in culture, and in an experiment, exposed to uv light. an analysis of the fibroblast dna will demonstrate which one of the following?