Is Hirschsprung disease a mendelian or a multifactorial disorder? Coding sequence mutations in RET, GDNF, EDNRB, EDN3, and SOX10 are involved in the development of Hirschsprung disease. The majority of these genes was shown to be related to Mendelian syndromic forms of Hirschsprung's disease, whereas the non-Mendelian inheritance of sporadic non-syndromic Hirschsprung disease proved to be complex; involvement of multiple loci was demonstrated in a multiplicative model. Hirschsprung disease (HSCR) is a multifactorial, non-mendelian disorder in which rare high-penetrance coding sequence mutations in the receptor tyrosine kinase RET contribute to risk in combination with mutations at other genes In this study, we review the identification of genes and loci involved in the non-syndromic common form and syndromic Mendelian forms of Hirschsprung's disease. The majority of the identified genes are related to Mendelian syndromic forms of Hirschsprung's disease. The non-Mendelian inheritance of sporadic non-syndromic Hirschsprung's disease proved to be complex; involvement of multiple loci was demonstrated in a multiplicative model Hirschsprung disease (HSCR) is a multifactorial, non-mendelian disorder in which rare high-penetrance coding sequence mutations in the receptor tyrosine kinase RET contribute to risk in combination with mutations at other genes For almost all of the identified HSCR genes incomplete penetrance of the HSCR phenotype has been reported, probably due to modifier loci. Therefore, HSCR has become a model for a complex oligo-/polygenic disorder in which the relationship between different genes creating a non-mendelian inheritance pattern still remains to be elucidated Hirschsprung disease (HSCR) is a multifactorial, non-mendelian disorder in which rare high-penetrance coding sequence mutations in the receptor tyrosine kinase RET contribute to risk in combination with mutations at other genes. The inheritance of Hirschsprung disease is generally consistent with sex-modified multifactorial inheritance with a lower threshold of expression in males. Hirschsprung disease (HSCR) is a multifactorial, non-mendelian disorder in which rare high-penetrance coding sequence mutations in the receptor tyrosine kinase RET contribute to risk in combination with mutations at other genes. Differential contributions of rare and common, coding and noncoding Ret mutations to multifactorial Hirschsprung disease liability. In the etiology of Hirschsprung disease various genes play a role; these are: RET, EDNRB, GDNF, EDN3 and SOX10, NTN3, ECE1, Mutations in these genes may result in dominant, recessive or multifactorial patterns of inheritance. The majority of the identified genes are related to Mendelian syndromic forms of Hirschsprung's disease In the etiology of Hirschsprung disease various genes play a role; these are: RET, EDNRB, GDNF, EDN3 and SOX10, NTN3, ECE1, Mutations in these genes may result in dominant, recessive or multifactorial patterns of inheritance On the basis of a skewed sex-ratio (M/F = 4/1) and a risk to relatives much higher than the incidence in the general population, HSCR has long been regarded as a sex-modified multifactorial disorder The inheritance of Hirschsprung disease is generally consistent with sex-modified multifactorial inheritance with a lower threshold of expression in males The non-Mendelian inheritance of sporadic non-syndromic Hirschsprung's disease proved to be complex; involvement of multiple loci was demonstrated in a multiplicative model