Objectives: to evaluate the effect of phototherapy on expression of BAX and Bcl2 genes in 
full term with hyperbilirubinemia. It comprised 18 full term and 18 preterm neonates with 
indirect hyperbilirubinemia who received phototherapy for 24 h, and 9 apparently healthy full 
term and 9 helthy preterm neonates with normal serum bilirubin level, as a control group. 
Determination: of the anti-apoptotic effect(s) of BCL2 gene and the pro-apoptotic effect(s) 
of (Bax) gene was achieved by quantitative assay of its product, (BCL2) protein, and BAX 
protein by ELISA. Results: there were significant decrease in the serum levels of bcl2 after 
phototherapy (P =0.001) and significant increase in serum levels of Bax protein after 
phototherapy (P <0.001) in hyperbilirubinemic full term neonates. Conclusion:
Hyperbilirubinemia does not influence on apoptosis, whereas phototherapy does and induces 
apoptosis in peripheral blood of hyperbilirubinemic full-term infants.