PD02 Xeroderma pigmentosum: from first symptoms to diagnosis

Abstract There is marked heterogeneity in the clinical features of xeroderma pigmentosum (XP), both between and within complementation groups. Effective management relies on early diagnosis, stringent photoprotection to mitigate skin cancer-related morbidity and mortality, and regular dermatological and ophthalmological examinations to detect and treat malignancies promptly. Despite these measures, diagnostic delays persist, highlighting the need for increased awareness among healthcare providers. Our aim was to evaluate presenting clinical features of XP and time from symptom onset to diagnosis. A retrospective review was performed of 133 patients with XP (67 female, 66 male; age 0–87 years) receiving multidisciplinary care at a national centre. In total, 100 patients were included, excluding 29 diagnosed through older siblings and four with incomplete histories. Data included complementation group, clinical features, ages of symptom onset and diagnosis, and referring specialty. The complementation groups represented included XP-A (n = 20), XP-B (n = 2), XP-C (n = 29), XP-D (n = 14), XP-E (n = 6), XP-F (n = 6), XP-G (n = 7) and XP-V (n = 16). By age 3 years, 84% of patients had developed clinical signs of the disease (excluding those presenting with skin cancers), yet the mean age at diagnosis was 12.2 years (median 6, range 0.5–64). Initial clinical signs varied significantly. Exposed-site pigmentary changes appeared at a mean age of 5 years (range 0.5–44) and were predominantly observed in XP-C (83%, mean 2.3 years) and XP-V (56%, mean 14.4 years). Photosensitivity, characterized by severe prolonged sunburn, was the primary symptom in patients with XP-D (100%), XP-F (100%), XP-G (86%) and XP-A (55%), excluding those with the milder XP-A variant. Median diagnostic delays were shorter in these complementation groups (range 3.2–11 years). Skin cancers at presentation were most common in XP-E (66%, mean 26 years), XP-V (44%, mean 35 years) and XP-C (7%, mean 16 years). Ocular signs (conjunctivitis and photophobia) were the first features in two patients with XP-C (ages 0.5 years and 1 year). Neurological symptoms presented first in two patients with XP-A, who exhibited developmental delays by age 2 years. Diagnostic delays were particularly pronounced in patients with XP-E and XP-V, with median delays of 28.5 and 21.5 years, respectively. Dermatologists made 73% of referrals, followed by geneticists (7%), general practitioners (10%), paediatricians (5%), neurologists (3%) and ophthalmologists (2%). Although most patients with XP develop clinical signs early in life, significant diagnostic delays exist, especially in those lacking severe sunburn reactions or pigmentary changes. Dermatologists are the primary referrers, underscoring their critical role in early recognition. Enhanced awareness across specialties is crucial to improve diagnostic timelines and outcomes.