XERODERMA-PIGMENTOSUM COCKAYNE-SYNDROME COMPLEX IN 2 PATIENTS - ABSENCE OF SKIN TUMORS DESPITE SEVERE DEFICIENCY OF DNA EXCISION-REPAIR

Two brothers had a complex combination of two DNA repair disorders: Co ckayne syndrome and xeroderma pigmentosum. This rare combination has p reviously been observed in only two other patients. The clinical signs shared by these two brothers and the two other previously described p atients include severe sun sensitivity, freckling, diminished stature, hearing and movement impairment, and neurologic degeneration. Althoug h defective UV-induced unscheduled DNA synthesis has been demonstrated (5% of normal), no skin cancers have appeared in these 38- and 41-yea r-old brothers, whereas skin cancers developed at a relatively early a ge in the two previously described patients who also had defective UV- induced unscheduled DNA synthesis.