Sister chromatid exchange in Chinese newborn infants treated with phototherapy for more than five days.

The frequency of sister chromatid exchange (SCE) was determined in newborn infants given phototherapy for more than five days, then determined again one year later. There were 8 healthy newborn infants and 15 icterus infants; 8 of these were treated with phototherapy for more than 5 days and the other 7 were not. In the follow-up study, 6 treated infants were evaluated. The results revealed that there was an increase in mean SCE frequency of peripheral lymphocytes after phototherapy, which reversed itself one year after treatment discontinuation. Prolonged continuous phototherapy may be responsible for the increase observed in SCEs in Chinese newborn.