Analysis of the RET, GDNF, EDN3, and EDNRB genes in patients with intestinal neuronal dysplasia and Hirschsprung disease.
BACKGROUND
Hirschsprung disease (HSCR) is a frequent congenital disorder with an incidence of 1 in 5000 live births, characterised by the absence of parasympathetic intramural ganglion cells in the hindgut resulting in intestinal obstruction in neonates and severe constipation in infants and adults. Intestinal neuronal dysplasia (IND) shares clinical features with HSCR but the submucosal parasympathetic plexus is affected. IND has been proposed as one of the most frequent causes of chronic constipation and is often associated with HSCR.


METHODS
We examined 29 patients diagnosed with sporadic HSCR, 20 patients with IND, and 12 patients with mixed HSCR/IND for mutations in the coding regions of the RET, GDNF, EDNRB, and EDN3 genes. The entire coding regions were analysed by single strand conformational polymorphism and DNA sequencing.


RESULTS
Only three RET mutations were detected in patients with HSCR. In patients with IND or a mixed HSCR/IND phenotype, no mutations in these genes were observed. While HSCR and HSCR/IND showed over representation of a specific RET polymorphism in exon 2, IND exhibited a significantly lower frequency comparable with that of controls.


CONCLUSIONS
The mutation frequency found in our sporadic HSCR patients (10%) and the allelic distribution of RET polymorphisms are comparable with earlier published data. A significantly different allelic distribution in an established HSCR associated polymorphism argues against common genetic pathways for HSCR and IND.
Gath
R
R
Department of Neuropathology, University of Bonn Medical Centre, D-53105 Bonn, Germany.
Goessling
A
A
Keller
K M
KM
Koletzko
S
S
Coerdt
W
W
Müntefering
H
H
Wirth
S
S
Hofstra
R M
RM
Mulligan
L
L
Eng
C
C
von Deimling
A
A
D000483:Alleles; D016022:Case-Control Studies; D029721:Drosophila Proteins; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D006627:Hirschsprung Disease / Q000235:genetics*; D006801:Humans; D009154:Mutation / Q000235:genetics*; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins / Q000235:genetics; D010375:Pedigree; D018807:Polymorphism, Single-Stranded Conformational; D011518:Proto-Oncogene Proteins / Q000235:genetics; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D017466:Receptors, Endothelin / Q000235:genetics; D017422:Sequence Analysis, DNA
D029721:Drosophila Proteins; C495039:GDNF protein, human; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; D017466:Receptors, Endothelin; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila