PREVALENCE AND PARENTAL ORIGIN OF DE-NOVO RET MUTATIONS IN HIRSCHSPRUNGS-DISEASE

In contrast with the reported almost exclusive paternal origin of de n ovo mutations in MEN 2A, FMTC and MEN 2B, de novo mutations in Hirschs prung patients arise both on paternal and maternal chromosomes. This d istinctive feature of RET mutations associated with Hirschsprung's dis ease and of the RET mutations associated with thyroid cancer indicates a basic biological difference between the mutational events leading t o the different phenotypes.