Clinical characteristics of three patients with UVs syndrome, a photosensitive disorder with defective DNA repair.

Recently, we established a new category of photosensitive disorder termed UVs syndrome. Cells from patients with UVs syndrome have a similar UV sensitivity as xeroderma pigmentosum (XP) cells, but have a normal level of unscheduled DNA synthesis (UDS) unlike XP. UVs syndrome is distinct from Cockayne syndrome (CS) or XP including XP variant (XP-V), as determined by studies of genetic factors using cell fusion, microinjection, and postreplication repair assays. In this study, we identified three Japanese patients with UVs syndrome: an 11-year-old girl, a 17-year-old male, and an 8-year-old boy. The first two patients were siblings, while the third was a case from a different family. All of these patients exhibited acute recurrent sunburn. Common clinical manifestations of these patients were slight erythema and dryness, a number of freckles on sun-exposed areas, and slight telangiectasia only seen on the cheek and nose. Patient 3 showed a lowered minimal erythema dose between 280 and 300 nm. The patients' fibroblasts showed similar characteristics to those in CS, such as UV sensitivity, and a failure of RNA synthesis (RRS) after UV irradiation, despite a normal level of UDS. Thus, UVs syndrome is a new hereditary photosensitive disorder with clinical manifestations similar to a mild form of XP but showing the cellular characteristics of CS.