Hirschsprung’s Disease and the related genes in Taiwan

• Main Authors: Wendy Yang, 楊曉文
• Other Authors: Pei-Lung, Chen
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/04309854290289301886

碩士 === 國立臺灣大學 === 臨床醫學研究所 === 104 === Background Hirschsprung’s disease (HSCR) is a congenital disease when the enteric ganglion cells were absent in the variable lengths of gastrointestinal tract. Several genes have been found to be involved in the development of HSCR, such as, RET, GDNF, EDNRB, SOX10, etc. Although RET is considered as the main gene related to HSCR, the phenotypic variability and incomplete penetrance observed in HSCR might suggest the involvement of modifier genes. Thus, a more thorough analysis of these HSCR-related genes might help to understand the HSCR genetic background that remains shrouded in mystery. Patients and Methods Patients proved to be HSCR by pathology were included after obtaining their written consent under the ethical guidance of the Institutional Review Board of Chang Gung Memorial Hospital, so as their parents, siblings, and/or off-springs. Total 30 families and 150 participants were included. Patients with syndromic presentations (such as Down syndrome) were disqualified. Peripheral blood is drawn for 20cc in all participants if possible, for children younger than 1-year- old, the amount is 10cc. After reviewing previous articles thoroughly, we identified 31 genes related to HSCR. A next-generation sequence (NGS) panel was designed accordingly. The DNA samples of all the patients were sent for NGS to detect possible genetic mutations. Further Sanger’s sequencing was performed to verify the mutations detected by NGS in the patients as well as their family members to characterize the mutation. Results There are 29 patients in 26 families were enrolled for NGS. Mutation of 13 different genes were identified in 23 patients. The detection rate of a possibly pathogenic mutation is 82.61%, which was much higher than previous reported. Frame-shift in RET, L1CAM and a stop codon in NRG1 were only found in long segment HSCR patients, indicating a clear-cut functional loss of the 3 HSCR-related genes and a severe form of the disease. Besides, there was an extraordinarily high frequency of SEMA3C mutations in our patients. For most of the patients, the relation between phenotype and the genotype is unclear, and our case number is too small to made solid conclusion in penetrance. Conclusion NGS is a powerful tool to work up for a multigenic disease, such as HSCR. An obvious loss of function in RET, L1CAM and NRG1 contributed to long segment HSCR, so such mutations of these genes might be employed for genetic counseling of HSCR family. Keywords: Next generation sequencing，Congenital megacolon, Hirschsprung’s disease, multigenic disease