Any xeroderma pigmentosum in which the cause of the disease is a mutation in the ERCC3 gene. The disease is Monarch Disease Ontology term MONDO_0012531 (xeroderma pigmentosum group B). Also known as: ERCC3 xeroderma pigmentosum, XP group B, XP, Group B, XP-B, XPB, XPBC, xeroderma pigmentosum caused by mutation in ERCC3, xeroderma pigmentosum group type B.