A single-nucleotide polymorphic variant of the RET proto-oncogene is underrepresented in sporadic Hirschsprung disease.
Hirschsprung disease (HSCR) is an inherited disorder characterised by absence of intrinsic ganglion cells in the distal gastrointestinal tract. Different susceptibility genes, involved in either the Ret-tyrosine kinase or the endothelin signalling pathways, contribute to HSCR phenotype. Interestingly, alterations of these genes are detected in only 30-50% of all HSCR patients, suggesting the involvement of modifier genes and/or additional genetic or environmental risk factors. In complex disorders common polymorphic variants can be associated with the disease phenotype, thus modifying the risk of recurrence. To investigate whether sequence variants of the RET proto-oncogene may be associated with the development of the HSCR phenotype, we analysed 92 Italian patients for the 2508C > T synonymous substitution in exon 14 (S836S) finding that the T allele is clearly less frequent than in control individuals (Fisher exact test P = 0.0002). On the other hand, this RET variant allele is overrepresented in patients affected with medullary thyroid carcinoma. Assuming a direct effect of this single-nucleotide polymorphism in predisposing to RET associated pathologies, we have performed functional tests which excluded any possible involvement of the C and T alleles in DNA-protein binding, transcript stability and RNA splicing and editing.
Griseri
P
P
Laboratorio di Genetica Molecolare, Istituto Giannina Gaslini, Genova, Italy.
Sancandi
M
M
Patrone
G
G
Bocciardi
R
R
Hofstra
R
R
Ravazzolo
R
R
Devoto
M
M
Romeo
G
G
Ceccherini
I
I
D000483:Alleles; D018276:Carcinoma, Medullary / Q000453:epidemiology / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D004314:Down Syndrome / Q000453:epidemiology / Q000235:genetics; D029721:Drosophila Proteins; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics; D014644:Genetic Variation; D006627:Hirschsprung Disease / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000235:genetics
D029721:Drosophila Proteins; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila