Symptoms occur from early infancy in 50 per cent of affected individuals:
- Extreme sensitivity to sunlight including severe blistering sunburns
- Persistent redness (sunburn) even upon minimal sun exposure
- Marked freckling in sun-exposed areas in a child under 2 years old.
Degrees of pigmentary change of the skin occur including freckling, dryness, premature skin ageing and development of skin cancers in childhood.
UV light causes damage to the surface of the eyes including the cornea, conjunctiva and eyelids. Neurological abnormalities occur in approximately 30 per cent of patients and include learning disability (see entry Learning Disability), spasticity (stiffness or tightness of muscle), poor coordination and deafness. XP patients may be of small stature and demonstrate developmental delay.