Development of Hepatocellular Carcinoma in Patients with Glycogen Storage Disease: a Single Center Retrospective Study.

BACKGROUND: Glycogen storage disease (GSD) is an inherited disorder leading to abnormal glucose metabolism and glycogen accumulation, and is associated with various complications including hepatic adenoma and hepatocellular carcinoma. The aim of this study was to analyze the risk factors for hepatic adenoma and its malignant change, and the hepatocellular carcinoma-free survival rate in patients with GSD who developed adenoma. METHODS: A total of 72 patients with GSD who were enrolled from March 1982 to September 2013 at Seoul National University Children's Hospital were retrospectively analyzed, and the median follow-up period was 19.2 years. RESULTS: Thirty-two patients (44.4%) developed hepatic adenoma at an age range of 7.9-26.3 years (median, 14.3 years). Among the 32 patients with hepatic adenoma, 4 patients (12.5%) developed hepatocellular carcinoma on an average interval of 6.7 years between the diagnosis of adenoma and the development of hepatocellular carcinoma. GSD type I and portacaval shunt operation were found to be the risk factors for hepatic adenoma development. The hepatocellular carcinoma-free survival rate at 10 years from adenoma development was 82%. CONCLUSION: The present study found that portacaval shunt operation increases the risk of development of hepatic adenoma in GSD patients, especially in GSD type I. The hepatic adenoma in GSD patients has a potential of malignant transformation, which should be keep in mind in follow-up process of the disease.

Multiplex Ligation-dependent Probe Amplification Analysis Subsequent to Direct DNA Full Sequencing for Identifying ATP7B Mutations and Phenotype Correlations in Children with Wilson Disease.

BACKGROUND: Mutations in ATP7B cause Wilson disease (WD). However, direct DNA full sequencing cannot detect all mutations in patients with WD. Multiplex ligation-dependent probe amplification (MLPA) analysis is reportedly useful in increasing the diagnostic yield in other genetic disorders with large deletions or insertions. The aim of this study was to evaluate whether the detection rate of ATP7B mutations can be increased by using MLPA. METHODS: We enrolled 114 children with WD from 104 unrelated families based on biochemical tests and direct DNA full sequencing. The patients with one or zero mutant allele were investigated using MLPA. We analyzed phenotypic correlations. RESULTS: Total allele frequency by full sequencing was 87.5%. Full sequencing revealed two mutant alleles in 80 of 104 unrelated children. One mutant allele was detected in 22 children, and no mutations were found in two children. Novel mutations including small deletions with frameshift mutations were identified by DNA sequencing. MLPA revealed no gross deletion or duplication in 24 children with one or zero mutant alleles. The number of detected mutations was not associated with hepatic manifestation, age of onset, Kayser-Fleischer ring, ceruloplasmin, and urinary Cu concentrations. CONCLUSION: MLPA showed a limited role to increase the mutation detection rate in children who do not receive a definite genetic diagnosis of WD through DNA full sequencing. This finding suggests that large deletions or duplications might be extremely rare in WD. Further development is needed to improve the genetic diagnosis of WD.

Genetic Polymorphisms in Autophagy-Associated Genes in Korean Children With Early-Onset Crohn Disease.

OBJECTIVE: The aim of the present study was to investigate the genetic polymorphisms of the autophagy-associated genes autophagy-related 16-like 1 (ATG16L1), immunity-related GTPase M (IRGM), Unc-51-like kinase 1 (ULK1), and NOD2 with respect to early-onset Crohn disease (CD) among Korean children. METHODS: A total of 65 patients with CD from the Seoul National University Children's Hospital, from January 2000 to May 2012, and 72 unaffected controls were selected. Twelve different single nucleotide polymorphisms (SNPs) were analyzed (TaqMan assay: ATG16L1 rs2241880, IRGM SNPs [rs13361189, rs4958847, rs1000113, rs10065172, and rs72553867], ULK1 SNPs [rs12303764, rs10902469, and rs7488085], NOD2 SNPs [Arg702Trp and Gly908Arg]; direct sequencing: NOD2 leu1007fsinsC). The onset age of patients was 8.6 ±â€Š4.7 years. Twelve patients (18.5%) had an onset age of <1 year. RESULTS: Two of the 12 SNPs showed significant results. IRGM rs1000113 exhibited an association with CD with respect to its minor allele frequency (odds ratio [OR] 1.71, 95% confidence interval [CI] 1.05-2.79, P = 0.03) and genotype distribution (dominant model: OR 2.17, 95% CI 1.07-4.39, P = 0.03). IRGM rs72553867 exhibited association with CD with respect to its minor allele frequency (OR 0.50, 95% CI 0.27-0.91, P = 0.02) and genotype distribution (dominant model: OR 0.50, 95% CI 0.23-0.94, P = 0.03). The 3 SNPs of NOD2 existed only as wild types for both groups. In the genotype-phenotype analysis, the onset age, disease location, and disease behavior exhibited no association. CONCLUSIONS: IRGM rs1000113 and IRGM rs72553867 exhibited associations with early-onset CD as risk loci and defense loci, respectively. This suggests that the autophagy pathway plays an important role in early-onset CD.

Very early-onset inflammatory bowel disease (IBD) in infancy is a different disease entity from adult-onset IBD; one form of interleukin-10 receptor mutations.

Infantile periods may have stronger genetic influences. Recently, studies on genetic defects in the interleukin-10 (IL-10) signaling pathway have provided new insights into inflammatory bowel disease (IBD). This study is to reveal whether mutations of IL-10 signaling pathway genes contribute to the phenotypes of IBD. Forty children who were diagnosed with IBD below the age of 10 years were enrolled. We sequenced the genes interleukin-10 receptor A (IL-10RA), IL-10RB and IL-10, and analyzed the clinical characteristics of very early-onset IBD (VEO-IBD). In total, 14 out of the 40 children developed their symptoms within 1 year of age. We found mutations in IL-10RA in 7 out of the 40 children (17.5%). All seven children had developed symptoms within the first year of life. Particularly, half of the children with infantile-onset IBD had IL-10RA mutations. None of the remaining 26 children diagnosed above 1 year of age had IL-10RA mutations. No mutations were found in IL-10RB and IL-10. Identified IL-10RA mutations were p.(R101W), p.(Y91C), p.(R262C), p.(R117H) and p.(W69R). IL-10RA mutations were associated with onset of infancy (P<0.001), perianal fistulae (P<0.001), poor response to medical management (P=0.017) and early surgical interventions (P<0.001). VEO-IBD in infancy is phenotypically and genetically different disease entity from adult-onset or older child-onset IBD. It has a strong association with IL-10 receptor gene. We should consider the genotyping of genes of the IL-10 signaling pathway including IL-10RA in patients with VEO-IBD, especially in whom with onset of perianal fistulae and severe colitis.

A mutation analysis of the AGL gene in Korean patients with glycogen storage disease type III.

Glycogen storage disease type III (GSD III) is an autosomal recessive disorder that is characterized by the excessive accumulation of abnormal glycogen in the liver and muscles and is caused by a deficiency in glycogen debranching enzyme (amylo-1,6-glucosidase, 4-alpha-glucanotransferase (AGL)) activity. To investigate the molecular characteristics of GSD III patients in Korea, we have sequenced the AGL gene in eight children with GSD III. All patients were compound heterozygotes. We identified 10 different mutations (five novel and five previously reported). The novel mutations include one nonsense (c.1461G>A, p.W487X), three splicing (c.293+4_293+6delAGT in IVS4, c.460+1G>T in IVS5, c.2682-8A>G in IVS21) and one missense mutation (c.2591G>C, p.R864P). Together, p.R285X, c.1735+1G>T and p.L1139P accounted for 56% of all alleles, while the remaining mutations are heterogeneous. These three mutations can be common in Korea, and further larger studies are needed to confirm our findings.

Long term outcomes of pediatric liver transplantation according to age.

Liver transplantation (LT) has been the key therapy for end stage liver diseases. However, LT in infancy is still understudied. From 1992 to 2010, 152 children had undergone LT in Seoul National University Hospital. Operations were performed on 43 patients aged less than 12 months (Group A) and 109 patients aged over 12 months (Group B). The mean age of the recipients was 7 months in Group A and 74 months in Group B. The patients' survival rates and post-LT complications were analyzed. The mean Pediatric End-stage Liver Disease score was higher in Group A (21.8) than in Group B (13.4) (P = 0.049). Fulminant hepatitis was less common in Group A (4.8%) than in Group B (13.8%) (P = 0.021). The post-transplant lymphoproliferative disorder and portal vein complication were more common in Group A (14.0%, 18.6%) than in Group B (1.8%, 3.7%) (P = 0.005). However, the 1, 5, and 10 yr patient survival rates were 93%, 93%, and 93%, in Group A and 92%, 90%, and 88% in Group B (P = 0.212). The survival outcome of pediatric LT is excellent and similar regardless of age. LTs in infancy are not riskier than those of children.

Correlations of plasma citrulline levels with clinical and endoscopic score and blood markers according to small bowel involvement in pediatric Crohn disease.

OBJECTIVE: Several studies have indicated that plasma citrulline levels reflect the extent of mucosal injury of the small intestine. This study was performed to determine whether plasma citrulline levels correlate with the disease activity in pediatric patients with Crohn disease (CD). METHODS: A total of 63 CD and 23 ulcerative colitis (UC) patients were included in this study. Disease severity was assessed by pediatric CD activity index (PCDAI), pediatric UC activity index, simplified endoscopic activity score for CD, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). The correlations among these variables and plasma citrulline levels were evaluated. We performed subgroup analysis whether correlations between plasma citrulline levels and disease activity depend on small bowel involvement in patients with CD. RESULTS: The plasma citrulline levels correlated negatively with CRP (r = -0.332, P = 0.008), ESR (r = -0.290, P = 0.022), and PCDAI (r = -0.424, P = 0.001) in patients with CD. The plasma citrulline levels were significantly lower in patients with jejunal involvement than in those without (P = 0.027). In subgroup analysis, patients with CD with jejunal involvement showed significantly negative correlations of plasma citrulline levels with CRP (r = -0.628, P = 0.016) and PCDAI (r = -0.632, P = 0.015); however, patients with CD without jejunal involvement revealed no correlations of plasma citrulline levels with CRP and PCDAI. There were no significant correlations between plasma citrulline levels and simplified endoscopic activity score for CD. There were no significant correlations of plasma citrulline levels with CRP, ESR, and pediatric UC activity index in patients with UC. CONCLUSIONS: Plasma citrulline levels correlated with disease severity as measured by PCDAI, CRP, and ESR in pediatric patients with CD with jejunal involvement.

Congenital chloride diarrhea in Korean children: novel mutations and genetic characteristics.

UNLABELLED: Congenital chloride diarrhea (CLD, OMIM#214700) is an autosomal recessive disorder caused by mutations in the solute carrier family 26 member 3 (SLC26A3) gene, which encodes an intestinal chloride/bicarbonate exchanger. While more than 50 mutations have been identified throughout the world, there have been no data on the genetic characteristics of the patients of East Asian ethnic origin. In this study, we performed genetic analysis by direct sequencing of the 20 exons and parts of exon-intron boundaries of the SLC26A3 gene in eight patients of Korean origin with non-consanguineous parents. We identified three novel mutations, including two splice-site mutations (c.2063-1G>T in intron 18, c.1047+3 A>C in intron 12) and one missense mutation (p.Ser134Asn in exon 5). One previously identified mutation was also found (p.Pro131Leu in exon 5). The most common mutation was c.2063-1G>T, which was found in at least one allele of all patients. CONCLUSION: This is the first report to demonstrate the genetic background of CLD in a single ethnic group of East Asian descent. The c.2063-1G>T mutation could be suggested as a founder mutation in Korean population so that the targeting sequencing for the mutation would be a cost-efficient screening method to confirm a diagnosis of CLD in patients of Korean descent.

Long-term outcomes of endoscopic variceal ligation to prevent rebleeding in children with esophageal varices.

After an episode of acute bleeding from esophageal varices, patients are at a high risk for recurrent bleeding and death. However, there are few reports regarding the long-term results of secondary prophylaxis using endoscopic variceal ligation (EVL) against variceal rebleeding in pediatrics. Thirty-seven, who were followed for over 3 yr post-eradication, were included in the study. The mean duration of follow up after esophageal variceal eradication was 6.4±1.9 yr. The mean time required to achieve the eradication of varices was 3.25 months. The mean number of sessions and O-bands needed to eradicate varices was 1.9±1.2 and 3.8±1.5, respectively. During the period before the first EVL treatment, 145 episodes of bleedings developed in 37 children. Over the 3 yr of follow-up after variceal eradication, only 4 episodes of rebleeding developed in 4 of 37 patients. The four rebleeding episodes consisted of an esophageal variceal bleed, a gastric variceal bleed, a duodenal ulcer bleed, and a bleed caused by hemorrhagic gastritis. There was no mortality during long-term follow up after variceal eradication. During long-term follow up after esophageal variceal eradication using solely EVL in children with esophageal variceal bleeds, rebleeding episodes and recurrence of esophageal varices were rare. EVL is a safe and highly effective method for the long-term prophylaxis of variceal rebleeding in children with portal hypertension.

Pediatric liver transplantation for fibropolycystic liver disease.

Fibropolycystic liver disease includes CHF, Caroli's syndrome, and Caroli's disease. Patients with Caroli's disease and Caroli's syndrome have an increased risk of recurrent cholangitis, intrahepatic calculi, biliary cirrhosis, and cholangiocarcinoma. The aim of this study was to examine the post-transplantation outcomes of children with fibropolycystic liver disease. Of the 158 children transplanted at Seoul National University Hospital, there were four patients with Caroli's syndrome, two patients with CHF, and one patient with Caroli's disease. One patient underwent combined liver/kidney transplantation. Associated renal manifestations included ARPKD in three children and nephronophthisis in one child. The indications for LT were recurrent cholangitis, decompensated cirrhosis, and refractory complications of portal hypertension. Both graft and patient survival rates were 100% at a median follow-up period of two yr after LT. Three children with growth failure achieved catch-up growth after LT. In three patients with ARPKD, mean serum creatinine levels increased from 0.53 mg/dL at the time of LT to 0.91 mg/dL at the last follow-up (p = 0.01). LT is an excellent option for children with complications from fibropolycystic liver disease. Renal function should be monitored cautiously after LT in the patients with ARPKD.

Clinical features of congenital portosystemic shunt in children.

UNLABELLED: Clinical features, images, complications, treatments, and prognosis of 10 children with congenital portosystemic shunt (CPSS) were reviewed. Nine children were diagnosed with intrahepatic shunts while one presented with extrahepatic shunt. CPSS was detected by prenatal ultrasonography in four infants. Three infants presented with galactosemia without an enzyme deficiency. Two children presented with mental retardation and attention deficit hyperactivity disorder. Pulmonary hypertension developed in two patients. Spontaneous closure occurred in four infants with intrahepatic shunts including patent ductus venosus. The shunts were closed using transcatheter embolizations in four patients with intrahepatic shunts. CONCLUSION: Intrahepatic shunts may close spontaneously. Transcatheter embolization is effective for the treatment of symptomatic intrahepatic shunts.

Independent introduction of two lactase-persistence alleles into human populations reflects different history of adaptation to milk culture.

The T(-13910) variant located in the enhancer element of the lactase (LCT) gene correlates perfectly with lactase persistence (LP) in Eurasian populations whereas the variant is almost nonexistent among Sub-Saharan African populations, showing high prevalence of LP. Here, we report identification of two new mutations among Saudis, also known for the high prevalence of LP. We confirmed the absence of the European T(-13910) and established two new mutations found as a compound allele: T/G(-13915) within the -13910 enhancer region and a synonymous SNP in the exon 17 of the MCM6 gene T/C(-3712), -3712 bp from the LCT gene. The compound allele is driven to a high prevalence among Middle East population(s). Our functional analyses in vitro showed that both SNPs of the compound allele, located 10 kb apart, are required for the enhancer effect, most probably mediated through the binding of the hepatic nuclear factor 1 alpha (HNF1 alpha). High selection coefficient (s) approximately 0.04 for LP phenotype was found for both T(-13910) and the compound allele. The European T(-13910) and the earlier identified East African G(-13907) LP allele share the same ancestral background and most likely the same history, probably related to the same cattle domestication event. In contrast, the compound Arab allele shows a different, highly divergent ancestral haplotype, suggesting that these two major global LP alleles have arisen independently, the latter perhaps in response to camel milk consumption. These results support the convergent evolution of the LP in diverse populations, most probably reflecting different histories of adaptation to milk culture.

Pyrosequencing-based molecular monitoring of the intestinal bacterial colonization in preterm infants.

OBJECTIVES: The aim of the study was to investigate the previously unexplored diversity of neonatal intestinal microbiota and monitor early intestinal colonization patterns in Korean preterm infants using high-throughput pyrosequencing technology combined with 16S rDNA-based molecular methods. SUBJECTS AND METHODS: A total of 46,369 partial 16S rDNA sequences obtained from 30 fecal samples serially taken from 10 very-low-birth weight preterm infants were analyzed. RESULTS: A significant proportion of the molecular species (21.9%) was found to be unclassified. The pathogenic or potentially pathogenic molecular species belonging to the classes Gammaproteobacteria and Bacilli were predominant during the entire observation period. Anaerobic or nonpathogenic molecular species belonging to the class Clostridia (except Clostridium difficile) and phyla Bacteroidetes were ubiquitous even within 72 hours after birth. The proportion of these species increased significantly at 1 month of age. The most ubiquitous and abundant major molecular genera common to all of the postnatal ages were Escherichia, Enterobacter, Enterococcus, Veillonella, Serratia, Staphylococcus, Roseburia, Acinetobacter, Citrobacter, Bacteroides, Faecalibacterium, Blautia, and Streptococcus. CONCLUSIONS: The diversity and dynamic nature of intestinal bacterial colonization in very-low-birth weight preterm infants were revealed using pyrosequencing technology. The results of the present pilot study may provide a basis to consider when investigating or interpreting the role of intestinal microbiota in certain preterm infant diseases such as necrotizing enterocolitis or systemic infection.

Orthopaedic manifestations of arthrogryposis-renal dysfunction-cholestasis syndrome.

BACKGROUND: Arthrogryposis-Renal dysfunction-Cholestasis (ARC) syndrome (MIM♯208085) is a rare multisystem disorder, which involves the kidney, liver, skin, and central nervous and musculoskeletal systems. It is inherited as an autosomal-recessive trait, associated with germ-line mutations in the VPS33B gene. In this study, the authors reviewed the orthopaedic manifestations of ARC syndrome. MATERIALS: Ten patients diagnosed as having ARC syndrome were the subjects of this study. ARC syndrome was confirmed by mutation analysis in 8 of the 10 patients. Medical records and radiographs were retrospectively reviewed with a focus on musculoskeletal manifestations. RESULTS: Seven patients either expired at 4 to 19 months of age or were presumed to have expired. The remaining 3 patients remained alive at the time of writing this manuscript and were aged from 7 to 23 months. All patients showed musculoskeletal symptoms and/or signs, which included vertical talus (7 feet, 4 patients), pes calcaneovalgus (4 feet, 3 patients), hip dislocation (6 hips, 3 patients), pathologic fractures (5 fractures in 5 patients), and rigid kyphosis (2 patients). No surgical intervention was performed. Orthopaedic treatments, other than fracture management, were abandoned soon after diagnoses were made. CONCLUSIONS: ARC syndrome should be included in the differential diagnosis of arthrogryposis. As there is no specific effective treatment for renal dysfunction and cholestasis, orthopaedic intervention should be postponed until long-term survival is expected, though this is unlikely. LEVEL OF EVIDENCE: Level IV, diagnostic studies, case series.

Germline mutation analysis of STK11 gene using direct sequencing and multiplex ligation-dependent probe amplification assay in Korean children with Peutz-Jeghers syndrome.

Background and Aims Peutz-Jeghers syndrome is an autosomal, dominantly inherited disease characterized by mucocutaneous hyperpigmentation and hamartomatous polyps of the gastrointestinal tract. In this study, mutation analysis of the STK11 gene was performed to establish the genetic background of Peutz-Jeghers syndrome in Korean children.Methods This study included 17 children who were diagnosed with Peutz-Jeghers syndrome based on clinical diagnostic criteria between July 2006 and December 2007.The clinical records of these children were reviewed retrospectively.Genomic DNA was extracted from the blood samples of each patient and used for direct sequencing and the MLPA (multiplex ligation-dependent probe amplification)assay.Results By direct sequencing, mutations in the STK11 gene were observed in five of 17 (29.4%) children with Peutz-Jeghers syndrome. Missense mutations were observed in four, and a frameshift mutation in one. All these mutations were present in the kinase domain of the STK11 gene. By MLPA analysis, mutations in the STK11 gene were observed in six (35.3%) children­exonic deletions were observed in five and exonic duplication in one. Conclusions The detection rate of STK11 gene mutations by direct sequencing is relatively low, even in children clinically diagnosed with Peutz-Jeghers syndrome. With the introduction of the MLPA assay as a new cytogenetic technique, large deletions and exonic duplications could also be detected in children with PJS. In the future, these results may be useful for the genetic diagnosis of Peutz-Jeghers syndrome in Korean children.

Novel CFTR mutations in a Korean infant with cystic fibrosis and pancreatic insufficiency.

Cystic fibrosis (CF) is an autosomal recessive disease that is very rare in Asians: only a few cases have been reported in Korea. We treated a female infant with CF who had steatorrhea and failure to thrive. Her sweat chloride concentration was 102.0 mM/L. Genetic analysis identified two novel mutations including a splice site mutation (c.1766+2T >C) and a frameshift mutation (c.3908dupA; Asn1303LysfsX6). Pancreatic enzyme replacement and fat-soluble vitamin supplementation enabled the patient to get a catch-up growth. This is the first report of a Korean patient with CF demonstrating pancreatic insufficiency. CF should therefore be considered in the differential diagnosis of infants with steatorrhea and failure to thrive.

A novel DHCR7 mutation in a Smith-Lemli-Opitz syndrome infant presenting with neonatal cholestasis.

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive malformation syndrome caused by a defect in cholesterol biosynthesis. The incidence is very low in Asians and only one case has been reported in Korea thus far. Recently, we found an infant with neonatal cholestasis. He had microcephaly, ambiguous genitalia, cleft palate, syndactyly of toes, patent ductus arteriosus and hypertrophic pyloric stenosis. The serum cholesterol was decreased and serum 7-dehydrocholesterol was markedly elevated. Genetic analysis of the DHCR7 gene identified a novel missense mutation (Pro227Ser) as well as a known mutation (Gly303Arg) previously identified in a Japanese patient with SLOS. Although rare in Korea, SLOS should be considered in the differential diagnosis of neonatal cholestasis, especially in patients with multiple congenital anomalies and low serum cholesterol levels.

Clinical and histological features of nonalcoholic fatty liver disease in children.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is becoming more frequently diagnosed as the prevalence of obesity in children increases rapidly. AIM: The aim of this study was to investigate the correlation of clinical findings with histopathologic features in children with NAFLD. METHODS: We reviewed the clinical data and liver histology results of children with biopsy-proven NAFLD at Seoul National University Hospital. NAFLD was classified as simple steatosis, type 1 nonalcoholic steatohepatitis (NASH), characterized by ballooning degeneration and perisinusoidal fibrosis, or type 2 NASH, characterized by portal inflammation and portal fibrosis. RESULTS: Among 80 total patients, 84% were male. All patients were obese or overweight. Insulin resistance was present in 96% of children. Perisinusoidal fibrosis was noted in 45% of children and portal fibrosis was noted in 77%. Simple steatosis was present in 22% of children, type 1 NASH in 34%, and type 2 NASH in 44%. No differences were found among NAFLD subtypes or NAFLD activity score with regard to sex, blood pressure, or levels of aminotransferase, fasting lipid, or insulin. Children with NASH were older and had higher body mass index than those with simple steatosis. Patients with type 2 NASH had higher body mass index and advanced fibrosis compared with patients with type 1 NASH. CONCLUSIONS: Obesity and older age are associated with development of NASH. Type 2 NASH is the most common form and associated with a greater severity of obesity and advanced fibrosis.

[Haplotype analysis and possible founder effect at the R778L mutation of the ATP7B gene in Korean patients with Wilson's disease].

BACKGROUND/AIMS: Wilson's disease (WD) is an inherited disorder of copper metabolism caused by alteration of the P-type adenosine triphosphatase (ATP) 7B gene. In this study, we analyzed the frequency of well-known mutations and constructed the first haplotypes for Koreans. In addition, we evaluated whether a founder effect existed in Korean patients with WD. METHODS: We obtained DNA samples from 21 patients with WD and their parents (total cohort n=63). ATP7B gene mutations were identified by direct sequencing methods, and microsatellite typing was performed at D13S315, D13S1325, and D13S316 with fluorescent dye-labeled primers. Any founder effect was identified by using 42 normal alleles from parents with a normal phenotype as a control group. The chi square test and Fisher's exact test were used for statistical analysis. RESULTS: Three common mutations were found in 23 chromosomes obtained from 21 patients: the R778L mutation at exon 8 (15/23, 65.2%), the A874V mutation at exon 11 (6/23, 26.1%), and the N1270S mutation at exon 18 (2/23, 8.7%). D13S315 and D13S316 showed linkage disequilibrium at alleles 5 and 4, respectively, in patients with the R778L mutation (P=0.0157 and 0.0001, respectively). The haplotype made up of these two alleles occurred significantly more frequently in patients with the R778L mutation (5-R778L-4, D13S315-mutation-D13S316) than in the controls (P=0.0018). CONCLUSIONS: The arche haplotype of the ATP7B gene in Korean patients with WD may be 5-R778L-4 (D13S315.mutation.D13S316), and it might illustrate a founder effect.