Recent molecular-genetic and histochemical studies of intestinal agang
lionosis have confirmed the initial classification established by Bola
nde, who considered Hirschsprng's disease (HD) a neurocristopathy. Thi
s paper is a critical review of the results of molecular-genetic studi
es carried out from 1992 to date. In particular, the author focuses on
the possible clinical impact of the identification of RET as a causat
ive gene for HD.