Table 1.

Overview of most abundant XP features and their average age of onset or frequency. Adapted from ^[5]

Feature	% / age	Feature	% / age
Cutaneous abnormalities		Neurological abnormalities
Median age of onset of symptoms	1.5 yr	Median age of onset	6 mo
Median age of onset of freckling	1.5 yr	Association with skin problems	33%
Photosensitivity	19%	Association with ocular abnormalities	36%
Cutaneous atrophy	23%	Low intelligence	80%
Cutaneous telangiectasia	17%	Abnormal motor activity	30%
Actinic keratoses	19%	Areflexia	20%
Malignant skin neoplasms	45%	Impaired hearing	18%
Median age of first cutaneous neoplasm	8 yr	Abnormal speech	13%
Ocular abnormalities		Abnormal EEG	11%
Frequency	40%	Microcephaly	24%
Median age of onset	4 yr	Abnormalities associated with neurological defects
Conjunctival injection	18%	Slow growth	23%
Corneal abnormalities	17%	Delayed secondary sexual development	12%
Impaired vision	12%
Photophobia	2%
Ocular neoplasms	11%
Median age of first ocular neoplasm	11 yr