CELLULAR RADIOSENSITIVITY OF PATIENTS WITH DIFFERENT TYPES OF NEUROFIBROMATOSIS

Skin fibroblast cell strains were developed from nine Saudi patients w ith different types of neurofibromatosis (NF) and nine healthy subject s (controls), and their radiosensitivity was compared following chroni c exposure to gamma-radiation at a dose rate of 0.0076 Gy/min (1 Gy = 100 rads). Cells from both normal appearing skin and cafe-au-lait spot s of the different NF patients (7 out of 9) clearly showed increased r adiosensitivity, with D10 (dose resulting in 10% survival) values of 2 .0-4.4 Gy for the former and 3.0-4.8 Gy for the latter, compared to th e normal controls (with D10 values of 6.1-10.6 Gy). These data provide further evidence of an association of enhanced cellular sensitivity t o chronic irradiation with NF regardless of the classes they belong to . Hypersensitivity to specific carcinogens may, thus, be a factor resp onsible for the increased propensity to cancer in these patients.