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Background and research purposes Hirschsprung in the incidence of congenital malformations in second place, the average per 5000 survived neonatal occurred in 1 patient. 1886, Danish doctors HaraldHirschsprung first described Hirschsprung disease, it is also known of Hirschsprung's Disease (HD). Hirschsprung children with in embryonic intestinal neurodevelopmental process, intestinal neuronal development come to a halt, intestinal myenteric plexus ganglion cell loss, resulting in abnormal contractions involved bowel and proximal colon compensatory expansion hypertrophy, the formation of megacolon. The clinical manifestations of complete or incomplete intestinal obstruction symptoms. HD is a genetic disease, the heritability of 80%. According to the characteristics of polygenic disease incidence or not is not only genetic factors, but the result of the mutual combined effects of the genetic and environmental factors, and the incidence of different gender threshold. The male and female prevalence ratio of 4:1, and having the characteristics of the male susceptible. HD survey of some pedigree, but also single-gene genetic characteristics, mode of inheritance: (1) autosomal dominant, (2) autosomal recessive autosomal recessive (3) sex (4) sexual autosomal dominant. But most of the Department of sporadic cases. Currently, with HD-related disease genes: RET proto-oncogene, EDNRB gene. This study investigated the RET gene mutation. RET genome consists of 20 exons, about 80kb, the last exon in charge of shear. RET gene mutations account for 50% of the total number of HD onset EDNRB mutations account for 5%. RET gene is located on the long arm of chromosome 1 District No. 10 with 2 the subzone (10all.2). Measured by PCR amplification, the HD patients visible 6,13,19 endures significant mutations, mutation of the method is a little mutation, frame shift wrong decoding gene deletion. RE T gene embryonic digestive tract development of ganglion cells play a significant role, now thinking RET gene mutation reported about the Chinese HD is still small. In this paper, the polymerase chain reaction - single strand conformation polymorphism (single strand confor ation polymorphism analysis of polymerase chalnreactlon products, referred to as PCR-SSCP) Chinese technical analysis of 20 patients with HD RET gene outside the 13 exons to detect RET gene mutation rate. Mutation point and mutant. Methods a clinical rectal biopsy and surgical pathology conventional diagnosed 2 each for the peripheral blood of patients with HD. Workers, salt extraction to genomic DNA. 13 outside high incidence of mutation in exon primers were designed using the primer design software RET gene exon 13, followed by a conventional polymerase chain reaction (PCR) amplification, the PCR product length of 253 HP. Method for mutation screening using single-strand conformation polymorphism (SSCP) analysis, abnormal band type PCR product was cloned into the pUC. -T vector DNA automated sequencer sequencing way to clear mutation sites and mutation. The results of a comprehensive analysis of the SSCP and DNA sequencing. 2 from the 20 patients, PCR-SSCP detected four cases with abnormalities in HD patients, the detection rate was 20% (4/20). SSCP results for cases of abnormal banding patterns were sequenced and found two mutations: point mutations: 18 888 T t. G (semi wrist acid mutated to phenylalanine); framework shift; 18 926 ins G. Track the parents of three children, proved to be the father of the children with the 5th sample SSCP abnormal bands and mutation sites consistent with the children, that is, 18888 T to G, results show that the five children HD, its parent genetic due. HD is hereditary. Conclusion 1.20 cases of Chinese people Hirschsprung patients RET gene exon 13 mutations of the four cases, the mutation detection rate of 20%. 2. In this experiment, the Chinese patients with Hirschsprung RET gene exon 13 mutations 18888 T to G, the semi sarcosine mutation is phenylalanine helium acid; 18926 ins G, the frameshift mutation. 3. In this study, four cases of RET gene mutations were heterozygous and one homozygous show that Hirschsprung RET gene heterozygous mutation can cause disease. 4. The pedigree analysis results confirm HD hereditary.
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