NLRP3 activation in macrophages promotes acute intestinal injury in neonatal necrotizing enterocolitis.

BACKGROUND: Macrophages are involved in various immune inflammatory disease conditions. This study aimed to investigate the role and mechanism of macrophages in regulating acute intestinal injury in neonatal necrotizing enterocolitis (NEC). METHODS: CD68, nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing 3 (NLRP3), cysteine aspartate-specific protease-1 (caspase-1), and interleukin-1ß (IL-1ß) in paraffin sections of intestinal tissues from NEC and control patients were detected with immunohistochemistry, immunofluorescence, and western blot. Hypertonic pet milk, hypoxia and cold stimulation were used to establish a mouse (wild type and Nlrp3-/-) model of NEC. The mouse macrophage (RAW 264.7) and rat intestinal epithelial cell-6 lines were also cultured followed by various treatments. Macrophages, intestinal epithelial cell injuries, and IL-1ß release were determined. RESULTS: Compared to the gut "healthy" patients, the intestinal lamina propria of NEC patients had high macrophage infiltration and high NLRP3, caspase-1, and IL-1ß levels. Furthermore, in vivo, the survival rate of Nlrp3-/- NEC mice was dramatically improved, the proportion of intestinal macrophages was reduced, and intestinal injury was decreased compared to those of wild-type NEC mice. NLRP3, caspase-1, and IL-1ß derived from macrophages or supernatant from cocultures of macrophages and intestinal epithelial cells also caused intestinal epithelial cell injuries. CONCLUSIONS: Macrophage activation may be essential for NEC development. NLRP3/caspase-1/IL-1ß cellular signals derived from macrophages may be the underlying mechanism of NEC development, and all these may be therapeutic targets for developing treatments for NEC.

Accurate prediction of biliary atresia with an integrated model using MMP-7 levels and bile acids.

BACKGROUND: Biliary atresia (BA) is a rare fatal liver disease in children, and the aim of this study was to develop a method to diagnose BA early. METHODS: We determined serum levels of matrix metalloproteinase-7 (MMP-7), the results of 13 liver tests, and the levels of 20 bile acids, and integrated computational models were constructed to diagnose BA. RESULTS: Our findings demonstrated that MMP-7 expression levels, as well as the results of four liver tests and levels of ten bile acids, were significantly different between 86 BA and 59 non-BA patients (P < 0.05). The computational prediction model revealed that MMP-7 levels alone had a higher predictive accuracy [area under the receiver operating characteristic curve (AUC) = 0.966, 95% confidence interval (CI): 0.942, 0.989] than liver test results and bile acid levels. The AUC was 0.890 (95% CI 0.837, 0.943) for liver test results and 0.825 (95% CI 0.758, 0.892) for bile acid levels. Furthermore, bile levels had a higher contribution to enhancing the predictive accuracy of MMP-7 levels (AUC = 0.976, 95% CI 0.953, 1.000) than liver test results. The AUC was 0.983 (95% CI 0.962, 1.000) for MMP-7 levels combined with liver test results and bile acid levels. In addition, we found that MMP-7 levels were highly correlated with gamma-glutamyl transferase levels and the liver fibrosis score. CONCLUSION: The innovative integrated models based on a large number of indicators provide a noninvasive and cost-effective approach for accurately diagnosing BA in children. Video Abstract (MP4 142103 KB).

Echocardiographic measurements of left ventricular dimensions and function in newborns with omphalocele and pulmonary.

PURPOSE: The purpose of this study was to explore echocardiographic parameters of the left ventricle (LV) in relation to the outcomes of omphalocele neonates with pulmonary hypertension (PH). METHODS: This retrospective study was conducted among omphalocele patients with PH born from 2019 to 2020. Patients in this study did not have additional severe malformations or chromosomal aberrations. Patients who died under palliative care were excluded. The echocardiographic parameters of LV were obtained within 24 h after birth. Clinical and outcomes data were recorded, echocardiograms evaluated for left ventricular internal dimension in end-diastole (LVIDd), end-diastolic volume (EDV), stroke volume (SV) and cardiac output index (CI), among others. RESULTS: There were 18 omphalocele newborns with PH, of whom 14 survived and 4 died. Both groups were comparable in the baseline characteristics. Non-survival was associated with a smaller LV [LVIDd (12.2 mm versus15.7 mm, p < 0.05), EDV (3.5 ml versus 6.8 ml, p < 0.05)] and with worse systolic function [SV (2.3 ml versus 4.2 ml, p < 0.05), and CI (1.7 L/min/m2 versus 2.9 L/min/m2, p < 0.01)]. CONCLUSION: In the cohort of omphalocele patients with PH, lower LVIDd, EDV, SV and CI were associated with mortality. LEVEL OF EVIDENCE: Level III.

Sirolimus treatment for neonate with blue rubber bleb nevus syndrome: A case report.

BACKGROUND: Blue rubber bleb naevus syndrome (BRBNS) is a rare disease that usually presents with multiple venous malformations in the skin and gastrointestinal tract. Lesions located in the gastrointestinal tract always result in chronic gastrointestinal bleeding and severe anemia. The successful management of BRBNS with sirolimus had been reported in many institutions, due to its impact on signaling pathways of angiogenesis. However, the experience in treatment of neonates with BRBNS was limited. CASE SUMMARY: A 38-day-old premature female infant born with multiple skin lesions, presented to our center complaining of severe anemia and hematochezia. Laboratory examination demonstrated that hemoglobin was 5.3 g/dL and contrast-enhanced abdominal computed tomography showed multiple low-density space-occupying lesions in the right lobe of the liver. She was diagnosed as having BRBNS based on typical clinical and examination findings. The patient was treated by transfusions twice and hemostatic drugs but symptoms of anemia were difficult to alleviate. A review of BRBNS case reports found that patients had been successfully treated with sirolimus. Then the patient was treated with sirolimus at an average dose of 0.95 mg/m2/d with a target drug level of 10-15 ng/mL. During 28 mo of treatment, the lesion was reduced, hemoglobin returned to normal, and there were no adverse drug reactions. CONCLUSION: This case highlights the dosing regimen and plasma concentration in neonates, for the current common empiric dose is high.

Association of T-helper cell cytokine level with age in patients with biliary atresia: a preliminary study.

BACKGROUND: The pathogenesis of biliary atresia (BA) is associated with an inflammatory process involving the biliary tree. This study aimed to investigate the association of T-helper cell cytokine levels with age in patients with BA. METHODS: Twenty-eight patients with BA were divided into three groups according to their age (< 2 months, 2-3 months, and ≥ 3 months). All the patients underwent Kasai portoenterostomy. Blood samples were collected from the patients preoperatively, and the liver tissue specimens were obtained during surgery. We detected serum levels of interleukin (IL)-1ß, IL-12p70, interferon (IFN)-γ, IL-6, IL-10, and transforming growth factor (TGF)-ß1 and liver expression of IL-1ß, IL-6, and TGF-ß1. RESULTS: The serum levels of IL-1ß, IL-12p70, IL-6, and IL-10 in patients aged ≥ 3 months were significantly higher than those in patients aged < 2 months. There were no significant age-related differences in the IL-1ß, IL-6 and TGF-ß1 expression levels in the liver tissue of patients with BA. CONCLUSIONS: The serum levels of IL-1ß, IL-6, IL-10 and IL-12p70 showed significant age-related differences in patients with BA. Interpretation of the role of cytokines in BA needs to take patient's age into consideration.

Multidisciplinary effort in treating children with hepatoblastoma in China.

The purpose of this study is to report the first nationwide protocol (Wuhan Protocol) developed by Chinese Children's Cancer Group and the results of multidisciplinary effort in treating hepatoblastoma. In this study, we reported the final analysis, which includes 153 hepatoblastoma patients in 13 hospitals from January 2006 to December 2013. The 6-year overall survival and event-free survival rates were 83.3 ± 3.1% and 71.0 ± 3.7%, respectively, in this cohort. The univariate analysis revealed that female (P = 0.027), under 5 years of age (P = 0.039), complete surgical resection (P = 0.000), no metastases (P = 0.000), and delayed surgery following neoadjuvant chemotherapy (P = 0.000) had better prognosis. In multivariate analysis, male, 5 years of age or above, stage PRETEXT III or IV, and incomplete surgical resection were among the some adverse factors contributing to poor prognosis. The preliminary results from this study showed that patients who underwent treatment following Wuhan Protocol had similar OS and EFS rates compared to those in developed countries. However, the protocol remains to be further optimized in standardizing surgical resection (including liver transplantation), refining risk stratification and risk-based chemotherapy.

Congenital duodenal obstruction in neonates: a decade's experience from one center.

BACKGROUND: Congenital duodenal obstruction (CDO) is one of the most common anomalies in newborns, and accounting for nearly half of all cases of neonatal intestinal obstruction. This study aimed to review our single-center experience in managing congenital duodenal obstruction while evaluate the outcomes. METHODS: We conducted a retrospective analysis of the records of all neonates dianogsed with congenital duodenal obstruction admitted to our center between January 2003 and December 2012. We analyzed demographic criteria, clinical manifestations, associated anomalies, radiologic findings, surgical methods, postoperative complications, and final outcomes. RESULTS: The study comprised 287 newborns (193 boys and 94 girls). Birth weight ranged from 950 g to 4850 g. Fifty-three patients were born prematurely between 28 and 36 weeks' gestation. Malrotation was diagnosed in 174 patients, annular pancreas in 66, duodenal web in 55, duodenal atresia or stenosis in 9, preduodenal portal vein in 2, and congenital band compression in 1. Twenty patients had various combinations of these conditions. Presenting symptoms included bilious vomiting, dehydration, and weight loss. X-rays of the upper abdomen demonstrated the presence of a typical double-bubble sign or air-fluid levels in 68.64% of patients, and confirmatory upper and/or lower gastrointestinal contrast studies were obtained in 64.11%. Multiple associated abnormalities were observed in 50.52% of the patients. Various surgical approaches were used, including Ladd's procedure, duodenoplasty, duodenoduodenostomy, duodenojejunostomy, or a combination of these. Seventeen patients died postoperatively and 14 required re-operation. CONCLUSIONS: Congenital duodenal obstruction is a complex entity with various etiologies and often includes multiple concomitant disorders. Timely diagnosis and aggressive surgery are key to improving prognosis. Care should be taken to address all of the causes of duodenal obstruction and/or associated alimentary tract anomalies during surgery.

Splenic hamartomas in two children.

Hamartomas are extremely rare splenic benign tumours in children. We present two cases, both in boys (6 and 8 years old), with left upper quadrant abdominal pain that were otherwise asymptomatic. Both patients showed a splenic mass on preoperative ultrasonography and magnetic resonance imaging (MRI). One patient had a focal splenic mass that was identified preoperatively with contrasted computed tomography (CT) scans. Both patients underwent a total splenectomy. Although multi-modality imaging findings were described preoperatively, the final diagnosis in each case was splenic hamartoma based on histology and immunohistochemistry. The postoperative courses were uneventful.

Incidence of pediatric metachronous contralateral inguinal hernia in children aged ≥1 year.

BACKGROUND: The management of the contralateral asymptomatic side when a child with initial unilateral inguinal hernia undergoes herniorrhaphy continues to be controversial. Age less than 6 months at initial herniorrhaphy is considered as a high risk factor of the occurrence of metachronous contralateral inguinal hernia (MCIH). We performed herniorraphy for patients ≥1 year with initial unilateral hernia at one-day-set outpatient-surgery department without any intervention of contralateral groin. In this study, we reviewed the characteristics of development of MCIH in this condition and discuss the management strategies of MCIH. METHODS: The subjects of this study were children who were treated at our outpatient-surgery department from January 2006 to December 2006. A total of 2129 patients with initial unilateral hernia and aged ≥1 year underwent an ipsilateral herniorhhaphy only. Patients were followed up for the development of MCIH to 60 months. The Chi-square test was used for intergroup comparison, a level of P<0.05 was considered as statistically significant. RESULTS: Among these children 1341 (63.0%) were obtained 60 months follow-up data, 1146 (85.5%) were boys and 195 (14.5%) were girls. MCIH developed in 70 (5.2%) patients, 61 were boys and 9 were girls. In 570 patients aged 12-23 months, 43 developed MCIH (7.5%); in 564 patients aged 24-59 months, 21 developed MCIH (3.7%); and in 207 patients ≥60 months, 6 patients developed MCIH (2.9%), the difference between these groups was highly significant (P=0.004). In male patients, 30 right-sided MCIHs occurred after 423 initial left-sided herniorrhaphies (7.1%) and 31 left-sided MCIHs occurred after 723 initial right-sided herniorrhaphies (4.3%), difference between these two groups was significant (P=0.041). Seventy-seven percent of the MCIHs occurred within 1 year, 94% occurred within 2 years after initial herniorraphy. CONCLUSIONS: As the overall incidence of MCIH in patients aged ≥1 year was 5.2%, routine contralateral groin exploration is not suggested. Transinguinal laparoscopy could be considered as an alternative of conventional "wait and see" policy, especially in patients less than 2 years or left-sided initial unilateral inguinal hernia. If "wait and see" policy is adopted, patients should be closely followed up for 2 years.

Laparoscopic cholecystostomy and bile duct lavage for treatment of inspissated bile syndrome: a single-center experience.

BACKGROUND: We aim to describe our experience of laparoscopic cholecystostomy and bile duct lavage in the treatment of inspissated bile syndrome. METHODS: Between January 2005 and December 2009, 16 infants with inspissated bile syndrome underwent laparoscopic cholecystostomy and bile duct lavage in our department. They were 7 males and 9 females, aged 40 days to 3 months, with an average of 65±23.4 days. A laparoscopic aided cholecystostomy was done. Cholangiography and bile duct lavage were performed during the operation. One week after the operation, bile duct lavage with saline was repeated every 2 to 3 days. According to bilirubin levels and liver function, the tube was kept for 2-4 weeks. RESULTS: The level of bilirubin decreased and liver function was greatly improved after bile duct lavage. Direct bilirubin level, aspartate aminotransferase and γ-GT were significantly decreased 1-2 months after the operation compared with those before surgery (P<0.05). CONCLUSIONS: The treatment strategy for inspissated bile syndrome with laparoscopic cholecystostomy and biliary duct lavage is feasible and effective.

Genome-wide association study identifies a susceptibility locus for biliary atresia on 10q24.2.

Biliary atresia (BA) is characterized by the progressive fibrosclerosing obliteration of the extrahepatic biliary system during the first few weeks of life. Despite early diagnosis and prompt surgical intervention, the disease progresses to cirrhosis in many patients. The current theory for the pathogenesis of BA proposes that during the perinatal period, a still unknown exogenous factor meets the innate immune system of a genetically predisposed individual and induces an uncontrollable and potentially self-limiting immune response, which becomes manifest in liver fibrosis and atresia of the extrahepatic bile ducts. Genetic factors that could account for the disease, let alone for its high incidence in Chinese, are to be investigated. To identify BA susceptibility loci, we carried out a genome-wide association study (GWAS) using the Affymetrix 5.0 and 500 K marker sets. We genotyped nearly 500 000 single-nucleotide polymorphisms (SNPs) in 200 Chinese BA patients and 481 ethnically matched control subjects. The 10 most BA-associated SNPs from the GWAS were genotyped in an independent set of 124 BA and 90 control subjects. The strongest overall association was found for rs17095355 on 10q24, downstream XPNPEP1, a gene involved in the metabolism of inflammatory mediators. Allelic chi-square test P-value for the meta-analysis of the GWAS and replication results was 6.94 x 10(-9). The identification of putative BA susceptibility loci not only opens new fields of investigation into the mechanisms underlying BA but may also provide new clues for the development of preventive and curative strategies.

Genome-wide association study identifies NRG1 as a susceptibility locus for Hirschsprung's disease.

Hirschsprung's disease (HSCR), or aganglionic megacolon, is a congenital disorder characterized by the absence of enteric ganglia in variable portions of the distal intestine. RET is a well-established susceptibility locus, although existing evidence strongly suggests additional loci contributing to sporadic HSCR. To identify these additional genetic loci, we carried out a genome-wide association study using the Affymetrix 500K marker set. We successfully genotyped 293,836 SNPs in 181 Chinese subjects with sporadic HSCR and 346 ethnically matched control subjects. The SNPs most associated with HSCR were genotyped in an independent set of 190 HSCR and 510 control subjects. Aside from SNPs in RET, the strongest overall associations in plausible candidate genes were found for 2 SNPs located in intron 1 of the neuregulin1 gene (NRG1) on 8p12, with rs16879552 and rs7835688 yielding odds ratios of 1.68 [CI(95%):(1.40, 2.00), P = 1.80 x 10(-8)] and 1.98 [CI(95%):(1.59, 2.47), P = 1.12 x 10(-9)], respectively, for the heterozygous risk genotypes under an additive model. There was also a significant interaction between RET and NRG1 (P = 0.0095), increasing the odds ratio 2.3-fold to 19.53 for the RET rs2435357 risk genotype (TT) in the presence of the NRG1 rs7835688 heterozygote, indicating that NRG1 is a modifier of HSRC penetrance. Our highly significant association findings are backed-up by the important role of NRG1 as regulator of the development of the enteric ganglia precursors. The identification of NRG1 as an additional HSCR susceptibility locus not only opens unique fields of investigation into the mechanisms underlying the HSCR pathology, but also the mechanisms by which a discrete number of loci interact with each other to cause disease.

Mutational analysis of SHH and GLI3 in anorectal malformations.

BACKGROUND: Anorectal malformations (congenital absence of the anal opening) are among the most common pediatric surgical problems and carry a significant chronic morbidity. METHODS: Direct sequencing was used to screen 88 anorectal malformations patients for mutations and polymorphisms in SHH and GLI3. These genes were chosen according to the phenotype presented by mutant mice and their expression patterns. RESULTS: We report on 10 GLI3 variants (IVS3+141C>G, T183A, IVS4+124T>C, IVS7+17G>A, IVS8+1 G>C, N503N, P941P, P998L, A1005A, A1039A) and four SHH mutation/variants (IVS1-49C>T, IVS2+111A>C, L214L, G290D). CONCLUSIONS: These variants are not over-represented in the healthy population and most are predicted to be benign. This study conveys the problematic assessment of the pathogenic role in disease of rare point mutations and variants.

Mapping of a Hirschsprung's disease locus in 3p21.

Hirschsprung's disease (HSCR) is a congenital disorder in which ganglion cells are absent in variable portions of the lower digestive tract according to which patients are classified. The RET gene is the major HSCR gene, although reduced penetrance of RET mutations and variable expression of HSCR phenotype indicates that more than one gene is required. An unidentified RET-dependent modifier on 3p21 appears to be necessary for transmission of the short HSCR (S-HSCR) phenotype. We investigated 6 Mb of the 3p21 region on a quest for the HSCR-susceptibility locus. Fifty-eight S-HSCR case-parent trios were genotyped using Sequenom technology for 214 tag single nucleotide polymorphisms (SNPs) distributed along 6 Mb of the 3p21 region. A five-marker haplotype, spanning a 118 kb gene-rich region, was found to be overtransmitted to affected offspring. The associated haplotype encompasses three genes involved in neurological phenotypes. Importantly, this association was replicated in an independent sample of 172 S-HSCR cases and 153 unrelated controls. Ranking markers by proximity to candidate genes or by expected functional consequences could be used in follow-up studies to finally pinpoint this HSCR locus.

[The relationship between postoperative complication and pathological features of 324 patients with neuronal intestinal malformations].

OBJECTIVE: To investigate the relationship between the morphological features of different types of neuronal intestinal malformations (NIM) and their postoperative complications. METHODS: The data of morphological and clinical features of 324 cases with NIM were analyzed retrospectively. RESULTS: In all 324 patients, 210 cases were Hirschsprung's disease (HD), 38 intestinal neuronal dysplasia (IND), 45 mixed HD/IND, 8 hypoganglionosis, 22 combined HD/hypoganglionosis and 1 immaturity of ganglion cells. The percentages of normal neuron in bowel of different NIM were 88.1%, 24.4%, 18.4%, 4/8, 27.7% and 0/1 in HD, HD/IND, IND, hypoganglionosis, HD/hypoganglionosis and immaturity of ganglion cells respectively. There were totally 46 cases complicated with recurrent postoperative enterocolitis (EC). Incidence of recurrent postoperative EC in HD patients was 6.7% while in IND/HD and IND patients was 35.6% and 28.9%, respectively. Incidences of EC in cases with the residual IND margins and with the normal margins were 38.2% and 8.7%, respectively. Incidence of EC in cases with transanal endorectal pull-through procedure and with transabdominal procedure was 18.0% and 8.3%, respectively. Nine cases underwent another procedure because of severe persistent constipation or EC after operation, including 4 cases HD/IND, 1 case IND, 3 cases HD and 1 case HD/hypoganglionosis. CONCLUSIONS: Neuron distribution is inconsistent with pathology of NIM. Postoperative EC are rare in the patients only with isolated HD. Furthermore, margins with residual IND and transanal endorectal pull-through procedure are risk factors to recurrent EC. However, the extension of excision about IND is uncertain and need further study.

Mutation of RET proto-oncogene in Hirschsprung's disease and intestinal neuronal dysplasia.

AIM: To investigate the genetic relationship between Hirschsprung's disease (HD) and intestinal neuronal dysplasia (IND) in Chinese population. METHODS: Peripheral blood samples were obtained from 30 HD patients, 20 IND patients, 18 HD/IND combined patients and 20 normal individuals as control. Genomic DNA was extracted according to standard procedure. Exons 11,13,15,17 of RET proto-oncogene were amplified by polymerase chain reaction (PCR). The mutations of RET proto-oncogene were analyzed by single strand conformational polymorphism (SSCP) and sequencing of the positive amplified products was performed. RESULTS: Eight germline sequence variants were detected. In HD patients, 2 missense mutations in exon 11 at nucleotide 15165 G-->A (G667S), 2 frameshift mutations in exon 13 at nucleotide 18974 (18974insG), 1 missense mutation in exon 13 at nucleotide 18919 A-->G (K756E) and 1 silent mutation in exon 15 at nucleotide 20692 G-->A(Q916Q) were detected. In HD/IND combined patients, 1 missense mutation in exon 11 at nucleotide 15165 G-->A and 1 silent mutation in exon 13 at nucleotide 18888 T-->G (L745L) were detected. No mutation was found in IND patients and controls. CONCLUSION: Mutation of RET proto-oncogene is involved in the etiopathogenesis of HD. The frequency of RET proto-oncogene mutation is quite different between IND and HD in Chinese population. IND is a distinct clinical entity genetically different from HD.

Polymerase chain reaction-single strand conformational polymorphism analysis of rearranged during transfection proto-oncogene in Chinese familial Hirschsprung's disease.

AIM: To investigate the relationship between mutations of rearranged during transfection (RET) proto-oncogene and Chinese patients with Hirschsprung's disease (HD), and to elucidate the genetic mechanism of familial HD patient at the molecular level. METHODS: Genomic DNA was extracted from venous blood of probands and their relatives in two genealogies. Polymerase chain reaction (PCR) products, which were amplified using specific primers (RET, exons 11, 13, 15 and 17), were electrophoresed to analyze the single-strand conformational polymorphism (SSCP) patterns. The positive amplified products were sequenced. Forty-eight sporadic HD patients and 30 normal children were screened for mutations of RET proto-oncogene simultaneously. RESULTS: Three cases with HD in one family were found to have a G heterozygous insertion at nucleotide 18,974 in exon 13 of RET cDNA (18,974insG), which resulted in a frameshift mutation. In another family, a heterozygosity for T to G transition at nucleotide 18,888 in the same exon which resulted in a synonymous mutation of Leu at codon 745 was detected in the proband and his father. Eight RET mutations were confirmed in 48 sporadic HD patients. CONCLUSION: Mutations of RET proto-oncogene may play an important role in the pathogenesis of Chinese patients with HD. Detection of mutated RET proto-oncogene carriers may be used for genetic counseling of potential risk for HD in the affected families.

[The mutation character of the RET proto-oncogene in Chinese patients with Hirschsprung's disease].

To clarify the pathogenesis of Hirschsprung's disease (HD) on molecular level and to reveal the relationship between the RET proto-oncogene and Chinese patients with HD, the mutations of the RET proto-oncogene were studied in 50 Chinese patients with HD and 30 normal children with an obstipation as control. Genomic DNA was extracted from venous blood of the HD patients and the normal children. Polymerase chain reaction (PCR) products, which were amplified using specific primers (RET; exon13), were electrophoresised to analyze the single-strand conformational polymorphism (SSCP) patterns. DNA sequences of exon 13 of the RET proto-oncogene were determined in patients showing abnormal SSCP bands. And then the familial tracking research was done for the patients with Exon 13 mutation. In 50 HD patients, seven cases were found with apparently abnormal SSCP bands. And three point mutations were proved by DNA sequencing. In the parents of seven HD patients with Exon 13 mutation, two patients' fathers had the same mutation as their children. The results suggest that the mutation of the RET proto-oncogene may have a high freqency in Chinese patients with HD, especially the heterozygous point mutation. And HD has the heredity tendency.