Advances in Molecular Genetics of Hirschsprung's Disease

Qin

et al. 2013

Cell Physiol Biochem

Background: MiR-141 has been confirmed to be associated with various human diseases. However, whether miR-141 is involved in the pathogenesis of Hirschsprung's disease (HSCR) remains unknown. Here, we design the experiment to reveal the relationship between miR-141 and HSCR. Methods: Quantitative real-time PCR and Western blot were used to detect the expression levels of miR-141 and its potential genes in 70 tissues of HSCR compared with 60 controls. Bisulfite sequencing PCR (BSP) assay was applied to explain the possible mechanism of the aberrant expression level of miR-141. We employed a dual-luciferase reporter assay to validate the regulation relation between miR-141 and CD47/CUL3. Cell migration, proliferation, apoptosis, and cell cycle progression were examined by transwell assay, MTT assay, and flow cytometry, respectively. Results: MiR-141 was down-regulated whereas CD47 and CUL3 expression was increased in colon tissues from patients with HSCR compared with control group, The increased level of CD47 and CUL3 induced by miR-141 reduced proliferation and migration of 293T and SH-SY5Y cells. Furthermore, this suppression was reversed by reducing of CD47 and CUL3. Hypermethylation of a CpG Island in the promoter region of miR-141 gene was confirmed in HSCR tissues. Conclusion: Aberrant reduction of miR-141 may play an important role in the pathogenesis of HSCR with the inhibiting affection on cell migration and proliferation abilities. The present study demonstrates for the first time the role of miR-141 and its target genes in the occurrence of HSCR, and provides us a new direction for the study of the pathogenesis of Hirschsprung's disease.

Section: Introductionmentioning

confidence: 99%

Aberrant Reduction of MiR-141 Increased CD47/CUL3 in Hirschsprung's Disease

Qin

et al. 2013

Cell Physiol Biochem

“…Gain-of-function mutations in RET cause multiple endocrine neoplasia (MEN) type 2 and FMTC [53]. On the contrary, loss-of-function mutations in RET are known to be risk factors for Hirschsprung disease (HSCR), which is caused by the congenital absence of parasympathetic ganglion cells in the intestinal tissues [54]. Furthermore, several mutations of this gene have also been reported in patients with congenital central hypoventilation syndrome (CCHS) [55].…”

Section: Multiple Endocrine Neoplasia Type 2 and Familial Medullary Tmentioning

confidence: 99%

Evaluation of reported pathogenic variants and their frequencies in a Japanese population based on a whole-genome reference panel of 2049 individuals

et al. 2017

Clarifying allele frequencies of disease-related genetic variants in a population is important in genomic medicine; however, such data is not yet available for the Japanese population. To estimate frequencies of actionable pathogenic variants in the Japanese population, we examined the reported pathological variants in genes recommended by the American College of Medical Genetics and Genomics (ACMG) in our reference panel of genomic variations, 2KJPN, which was created by whole-genome sequencing of 2049 individuals of the resident cohort of the Tohoku Medical Megabank Project. We searched for pathogenic variants in 2KJPN for 57 autosomal ACMG-recommended genes responsible for 26 diseases and then examined their frequencies. By referring to public databases of pathogenic variations, we identified 143 reported pathogenic variants in 2KJPN for the 57 ACMG recommended genes based on a classification system. At the individual level, 21% of the individuals were found to have at least one reported pathogenic allele. We then conducted a literature survey to review the variants and to check for evidence of pathogenicity. Our results suggest that a substantial number of people have reported pathogenic alleles for the ACMG genes, and reviewing variants is indispensable for constructing the information infrastructure of genomic medicine for the Japanese population.

J Genet Syndr Gene Ther

“…The aganglionic intestinal segment is unable to relax, which leads to functional obstruction. [8–11]…”

Section: Introductionmentioning

confidence: 99%

Novel Mutation-Deletion in the PHOX2B Gene of the Patient Diagnosed with Neuroblastoma, Hirschsprung’s Disease, and Congenital Central Hypoventilation Syndrome (NB-HSCR- CCHS) Cluster

Szymońska

Borgenvik

Karlsvik

et al. 2015

Introduction Neuroblastoma (NB), Hirschsprung disease (HSCR), Congenital Central Hypoventilation Syndrome (CCHS), clinically referred as the NB-HSCR-CCHS cluster, are genetic disorders linked to mutations in the PHOX2B gene on chromosome 4p12. Specific Aim The specific aim of this project is to define the PHOX2B gene mutations as the genomic basis for the clinical manifestations of the NB-HSCR-CCHS cluster. Patient A one day old male patient presented to the Jagiellonian University Medical College (JUMC), American Children Hospital, neonatal Intensive Care Unit (ICU) due to abdominal distention, vomiting, and severe apneic episodes. With the preliminary diagnosis of the NB-HSCR-CCHS, the blood and tissue samples were acquired from the child, as well as from the child’s parents. All procedures were pursued in accordance with the Declaration of Helsinki, with the patient’s Guardian Informed Consent and the approval from the Institutional Review Board. Genetic/Genomic Methods Karyotyping was analyzed based upon Giemsa banding. The patient’s genomic DNA was extracted from peripheral blood and amplified by polymerase chain reaction. Direct microfluidic Sanger sequencing was performed on the genomic DNA amplicons. These procedures were pursued in addition to the routine clinical examinations and tests. Results G-banding showed the normal 46 XY karyotype. However, genomic sequencing revealed a novel, heterozygous deletion (8 nucleotides: c.699–706, del8) in exon 3 of the PHOX2B gene on chromosome 4. This led to the frame-shift mutation and malfunctioning gene expression product. Conclusion Herein, we report a novel PHOX2B gene mutation in the patient diagnosed with the NB-HSCR-CCHS cluster. The resulting gene expression product may be a contributor to the clinical manifestations of these genetic disorders. It adds to the library of the mutations linked to this syndrome. Consequently, we suggest that screening for the PHOX2B mutations becomes an integral part of genetic counseling, genomic sequencing of fetal circulating nucleic acids and / or genomes of circulating fetal cells prenatally, while preparing supportive therapy upon delivery, as well as on neonates' genomes of intubated infants, when breathing difficulties occur upon extubation. Further, we hypothesize that PHOX2B may be considered as a potential target for gene therapy.