Functional haplotypes of the RET proto-oncogene promoter are associated with Hirschsprung disease (HSCR)

• Published in: Human molecular genetics Vol. 12; no. 24; pp. 3207 - 3214
• Main Authors: Fitze, Guido, Appelt, Hella, König, Inke R., Görgens, Heike, Stein, Ulrike, Walther, Wolfgang, Gossen, Manfred, Schreiber, Matthias, Ziegler, Andreas, Roesner, Dietmar, Schackert, Hans K.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 15.12.2003; Oxford Publishing Limited (England)
• Subjects: Biological and medical sciences; Classical genetics, quantitative genetics, hybrids; Female; Fundamental and applied biological sciences. Psychology; Gene Frequency; Genetics of eukaryotes. Biological and molecular evolution; Haplotypes; Hirschsprung disease; Hirschsprung Disease - genetics; Human; Humans; Male; Polymorphism, Genetic; Promoter Regions, Genetic; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins - metabolism; Proto-Oncogene Proteins c-ret; Receptor Protein-Tyrosine Kinases - genetics; Receptor Protein-Tyrosine Kinases - metabolism; RET gene; Signal Transduction; Tumor Cells, Cultured; Human; Typing; Transcription promoter; Hirschsprung disease; Functional analysis; Molecular biology; Haplotype; Protooncogene
• ISSN: 0964-6906; 1460-2083; 1460-2083
• DOI: 10.1093/hmg/ddg354

The activation of the RET signaling pathway during embryogenesis is a crucial prerequisite for a directional migration of enteric nervous system progenitor cells. Loss-of-function germline mutations of the RET proto-oncogene are reported in familial and sporadic cases of Hirschsprung disease (HSCR) with a variable frequency. Furthermore, variants of several RET polymorphisms are over- or under-represented in HSCR populations. Specifically, the c.135A RET variant has been previously shown to be strongly associated with the HSCR phenotype. We have reported an HSCR-phenotype modifying effect of the RET c.135G>A polymorphism due to a within-gene interaction in patients harboring RET germline mutations, yet the function of the c.135G>A variant is unknown. The basic RET promoter region was investigated by DNA sequencing approach in 80 HSCR patients. Identified polymorphisms were genotyped in the HSCR and in a control population and haplotypes were reconstructed. The dual-luciferase assay was used to evaluate the activity of different RET promoter haplotypes. We demonstrate that variants of two RET promoter polymorphisms −5G>A and −1C>A from the transcription start site are associated with HSCR. Furthermore, the −5G>A polymorphism is in strong linkage disequilibrium with the c.135G>A polymorphism. The promoter haplotype −5/−1AC associated with HSCR has a significantly lower activity in an in vitro dual-luciferase expression assay compared with those haplotypes identified in the majority of normal controls. These data suggest a role for RET haplotypes containing the −5A promoter variant in the etiology of HSCR.