Abstract: Objective To evaluate the clinical significant and expression of the GDNF/ GFRα1/RET in the distal of rectum with congenital Imperforate anus (CIA). Methods Specimens were collected from resected colon in the 3 cm away to the anus and the distal of rectum with 12 CIA patients in Tianjin Children’s Hospital. Haematoxylin and eosin(HE) staining, immunohistochemical(IHC) staining and real-time quantitative(RT-PCR) methods were done in the different site of samples with CIA for RET, GDNF and GFRα1 expression. Results It was decreased for expression of ganglia and negative for expression of RET, GDNF and GFRα1 in the distal of rectum with 12 CIA patients. There were ganglionic cells in the 3cm away to the anus with 12 CIA patients. It was positive for expression of RET, GDNF and GFRα1 in the 3cm away to the anus with 12 CIA patients. middle and low imperforate anus were more expression than high imperforate anus in the expression of neurotrophic factors that had RET, GDNF and GFRα1. The former were more complications than the latter in terms of postoperative function recovery. Conclusions The unsatisfactory anorectal function is possible related to the decrease or lost of neurotrophic factors（GDNF/ GFRα1/RET） and ganglia in the myenteric plexuses.

Key words: Congenital Imperforate anus, Neurotrophic factors, RT-PCR, immunohistochemical, Function