Hereditary pancreatitis]

The first family of hereditary pancreatitis was described in 1952. The mode of inheritance is autosomal dominant trait with an 80% of penetrance rate. Although hereditary pancreatitis is rare, this disorder has provided valuable insights in understanding the pathophysiology of pancreatitis and pancreatic cancer. The causative gene of hereditary pancreatitis was identified in 1996 through mutational analysis of genes within chromosome 7q35. Most forms of hereditary pancreatitis are caused by one of two common mutations, R122H in the third exon or N29I in the second exon of the cationic trypsinogen gene (protease serine 1, PRSS1). R122H mutation is the most common PRSS1 mutation. Additional mutations of the cationic trypsinogen gene have been described. In Korea, first family of hereditary pancreatitis with cationic trypsinogen gene mutation revealed an arginine to histidine amino acid substitution at the residue 122. Patients with hereditary pancreatitis present with symptoms at an early age and have significant risk for the development of chronic pancreatitis and pancreatic cancer. The risk of pancreatic cancer is estimated to be 53-fold higher after the age of 50 years than the general population. The risk of pancreatic cancer is not related to the type of mutation. Since hereditary pancreatitis is a strong risk factor for pancreatic cancer, it is important to establish a diagnostic criteria for diagnosis and surveillance. However, there are potential benefits, risks and limitations in genetic testing for hereditary pancreatitis. It is difficult to provide the proper treatment, but recent developments in therapeutic approaches may be helpful in caring hereditary pancreatitis. This article includes the current status, pathogenesis, clinical features, and management of hereditary pancreatitis including the aspects of pancreatic cancer.     

Hereditary pancreatitis as the premalignant disease: a Japanese case of pancreatic cancer involving the SPINK1 gene mutation N34S

Mutations in the cationic trypsinogen gene are acknowledged as a risk factor for pancreatic cancer in patients with hereditary pancreatitis. However, whether patients with mutations in other genes, such as the serine protease inhibitor Kazal type 1 (SPINK1) gene, are also at a higher risk of pancreatic cancer remains unknown. We report a case of pancreatic cancer associated with chronic calcifying pancreatitis in a patient with a homozygous N34S mutation in the SPINK1 gene. A 44-year-old woman was hospitalized due to obstructive jaundice. Preoperative examination showed a tumor in the head of the pancreas and multiple pancreatic stones; pancreatoduodenectomy revealed a solid tumor, 3.0 x 2.5 cm in size, in the head of the pancreas, and numerous pancreatic stones throughout the pancreas. Pathologic studies revealed moderately differentiated tubular adenocarcinoma. Mutational analyses of the SPINK1 and PRSS1 genes in members of the patient's family were carried out. The homozygous N34S mutation in the SPINK1 gene was found in the patient and her older sister, who was previously diagnosed with chronic calcific pancreatitis and had undergone the Frey operation. The patient's parents and brother were unaffected carriers of the N34S heterozygous mutation. No family members had any mutations in the cationic trypsinogen gene. To our knowledge, this is the first reported case of chronic pancreatitis accompanied by pancreatic cancer in a patient with the SPINK1 N34S mutation. Although this case does not meet the classic criteria of hereditary pancreatitis, it does suggest that the SPINK1 N34S mutation may be associated with cancer development in patients with hereditary pancreatitis. Further prospective, multicenter trials investigating secondary screening for pancreatic cancer in hereditary pancreatitis are necessary to clarify the role of SPINK1 mutations in the development of pancreatic cancer.     

Frequent deletions of tumor suppressor genes in pure pancreatic juice from patients with tumoral or nontumoral pancreatic diseases

Background/Aims: K-ras codon 12 mutation is the most frequent genetic alteration in pancreatic cancer. Sensitivity and specificity of K-ras are not high enough to detect all pancreatic cancers, especially at early stage. This study investigated whether detection of p16 and/or DPC4 deletions along with K-ras mutation in DNA samples could improve the definition of patients at risk of pancreatic cancer. Methods: K-ras mutations were investigated by sequencing. p16 and DPC4 homozygous deletions were studied using comparative multiplex polymerase chain reaction of DNA in pancreatic juice sampled during endoscopic retrograde pancreatography in 57 patients with either pancreatic cancer (group I, 18 patients), chronic pancreatitis (group II, 20 patients), or nontumoral pancreatobiliary disease (group III, 19 patients). Results: The frequencies of Ki-ras mutations were 61% in group I, 10% in group II, and 10.5% in group III. The frequencies of p16 exon 2 and DPC4 deletions were, respectively, 28 and 36% in group I, 50 and 58% in group II, and 24 and 36% in group III. Conclusions: The combination of p16 and DPC4 deletions with K-ras mutation does not improve the diagnosis of pancreatic cancer based on K-ras mutation alone. These data suggest that tumor suppressor gene inactivation can occur with a high frequency during nonmalignant pancreatic diseases.     

MUTYH Exon 7 and 13 Mutations Associated with Colorectal Cancer (MAP Syndrome) Are Not Commonly Associated with Sporadic Pancreatic Cancer

Background: Biallelic MUTYH exon 7 and 13 mutations are associated with a high frequency of somatic K-ras gene guanine to thymine transversion mutations at codon 12 position 1 in MUTYH-associated polyposis patients who have increased risk of colon cancer. The purpose of this study was to determine if a similar association exists between exon 7 and 13 MUTYH mutations and pancreatic cancer. Methods: Genomic DNA samples from 140 patients with pancreatic cancer and 107 controls were sequenced and analyzed for mutations in each of MUTYH exons 7 and 13. Results: Two patients with pancreatic cancer were identified as heterozygous for a MUTYH Y165C germline mutation. One pancreatic cancer patient was heterozygous for a G382D mutation and an additional patient was heterozygous for a novel missen se mutation, L406M. No biallelic mutations were identified in pancreatic cancer or control subjects. Conclusion: Despite their association with somatic K-ras mutations and an increased risk of colorecta! cancer in MUTYH-associated polyposis patients, MUTYH exon 7 and 13 mutations were not associated with pancreatic cancer in our cohort.     

CFTR Gene Mutation in Patients with Apparently Idiopathic Pancreatitis: Lack of Phenotype-Genotype Correlation

Background and Aims: Despite an extensive search, no cause is found for recurrent acute/chronic pancreatitis (idiopathic pancreatitis (IP)) in about 20% of patients. In these patients, CFTR gene mutations may be identified. The aims of this study were (1) to describe the natural history of pancreatitis associated with the CFTR mutation, (2) to look for genotype-phenotype correlations, and (3) to examine the frequency of CFTR mutations in a population of patients with IP. Results: 100 consecutive patients with IP were included between 1998 and 2005. 50% had one of the 33 most frequent CFTR gene mutations (common CF mutations, uncommon mutations causing variable phenotypes and variants of unknown significance in 28, 44 and 28%, respectively). Patients with a CFTR gene mutation were significantly younger than those without (34 vs. 40 years, p = 0.03). Duration of follow-up (3.5 vs. 3 years), proportion of patients with acute pancreatitis as first symptom (76 vs. 74%) were not significantly different. Signs of chronic pancreatitis (ductal changes and pancreatic calcifications), pseudocysts, common bile duct stenosis, exocrine or endocrine insufficiency occurred in 36,26,4,10 and 12% of patients with CFTR gene mutations respectively, which was not different from patients without mutations. No phenotype-genotype correlation was observed. Conclusions: In patients with IP, clinical and radiological manifestations are not related to the presence of a CFTR gene mutation or to the type of mutation.     

Diagnosis of Pancreatic Adenocarcinoma Using Protein Chip Technology

Background: To develop a serum-specific protein fingerprint which is capable of differentiating samples from patients with pancreatic cancer and those with other pancreatic conditions. Methods: We used SELDI-TOF-MS coupled with CM10 chips and bioinformatics tools to analyze a total of 118 serum samples in this study; 78 serum samples were analyzed to establish the diagnostic models and the other 40 samples were analyzed on the second day as an independent test set. Results: The analysis of this independent test set yielded a specificity of 91.6% and a sensitivity of 91.6% for pattern 1, which distinguished pancreatic adenocarcinoma (PC) from healthy individuals and a specificity of 80.0% and a sensitivity of 90.9% for pattern 2, which distinguished PC from chronic pancreatitis. Conclusion: This study indicated that the SELDI-TOF-MS technique can facilitate the discovery of better serum tumor biomarkers and a combination of specific models is more accurate than a single model in diagnosis Of PC.     

Serum Adenosine Deaminase Levels in Pancreatic Diseases

Background: Adenosine deaminase (ADA) is found in most tissues including the pancreas. Its role in inflammation and malignancy has been studied experimentally. To date, serum ADA levels in pancreatic diseases have not been studied before. Aim: To assess the levels of ADA in patients with pancreatitis and cancer of the pancreas. Methodology: Serum levels of ADA were investigated in 14 cases with acute pancreatitis (mean age 46 years; male/female 5/9), 38 with chronic pancreatitis (mean age 46 years; male/female 25/13), 21 with cancer of the pancreas (mean age 67 years; male/female 11/10), and 21 healthy controls (mean age 40 years; male/female 11/10). The ADA levels were also compared among patients with pancreatic cancer with regard to tumor size and localization and the presence of métastases. Correlation analysis between ADA and CA 19.9 was also performed. Results: Serum ADA levels were 12.66 (9.54–20.72), 12.51 (8.88–26.64), 15.36 (10.20–21.05) and 9.39 (6.58–11.84) U/l in patients with acute pancreatitis, chronic pancreatitis, pancreatic cancer, and healthy controls, respectively. Serum ADA levels were significantly higher in acute and chronic pancreatitis, and pancreatic cancer patients compared to the control group (p < 0.05). Pancreatic cancer patients had significantly higher serum ADA levels when compared with acute and chronic pancreatitis cases (p < 0.05). The serum ADA levels were comparable according to tumor size and location and the presence of metastases. There was a linear correlation between serum ADA and CA 19-9 levels (p = 0.027, r = 0.552). Conclusions: Our data suggest that the ADA enzyme may play a role in inflammatory diseases of the pancreas. Serum ADA levels increase in pancreatic disorders especially in pancreatic cancer. It may be a serum marker for the diagnosis of pancreatic cancer.     

DNA Mutational Differences in Cytological Specimens from Pancreatic Cancer and Cholangiocarcinoma

Background/Aims: Preoperative distinction between pancreatic cancer (PC) and extrahepatic cholangiocarcinoma (CC) is desirable due to diverging management options, and to optimize enrollment into neoadjuvant trials. Methods: A single-center retrospective study of patients with PC or CC was undertaken. Four blinded pathologists reviewed all cases and reached a consensus diagnosis (PC or CC). Microdissection-based multiple microsatellite loss analysis and direct sequencing of K-ras oncogene was performed and compared for PC and CC. Results: Of 33 cases studied (17 males; 16 PC, 17 CC; 10 with primary sclerosing cholangitis), a K-ras mutation was present in 14/16 (87.5%) PC and 1/17 (5.9%) CC cases (p<0.001), sensitivity and specificity were 87.5 and 94%, respectively. The mean fractional mutational rate was higher in PC (0.51; 95% CI 0.45–0.58) compared to CC (0.34; 95% CI 0.28–0.39, p<0.001). Conclusions: The presence of a K-ras mutation in cytology specimens distinguishes PC from CC in this study.     

Familial pancreatic cancer and hereditary syndromes: screening strategy for high-risk individuals

Globally, and almost evenly across nations, a familial disposition can be found in 4–10% of patients with pancreatic cancer (PC). A family history of PC is a risk for this disease and the risk level changes in correlation with the number of affected relatives. Several hereditary syndromes with potential germline mutation also have a high risk for PC; however, little is yet known regarding the genes responsible for familial pancreatic cancer (FPC). Characteristics of FPC cases are similar to those of other familial tumors, including younger onset than in sporadic cases and an ethnic difference (Ashkenazi Jewish > other Caucasian). Other risks resemble those of sporadic cases and include smoking and diabetes mellitus. People with several genetic syndromes, including Peutz–Jeghers syndrome, hereditary pancreatitis, breast-ovarian cancer syndrome, hereditary nonpolyposis colorectal cancer, and familial adenomatous polyposis also have an increased risk of PC. In many countries, but not yet in Japan, screening of these high-risk individuals is now ongoing for the detection of early PC under established familial pancreatic cancer registries. In addition to the ordinary risk factors, such as smoking, diabetes, pancreatitis, cysts, duct ectasia, and intraductal papillary mucinous neoplasm (IPMN), individuals with a family history of PC and hereditary syndromes are expected to be entered into the screening protocol.     

Genetic Mutations in a Spanish Population with Chronic Pancreatitis

Background/Aims: Mutations in the PRSS1 and the SPINK1 genes have variably been associated with alcohol-related, idiopathic and hereditary chronic pancreatitis (CP). The aim of this study was to determine for the first time the significance of PRSS1, SPINK1 mutations and genetic variants of AAT in a group of Spanish patients with CP. Methods: 104 consecutive patients with CP were included, as well as 84 healthy control subjects. The R122H and N29I mutations in the PRSS1 gene, the N34S mutation in the SPINK1 gene and PiS and PiZ mutations in the AAT gene were analyzed by RFLP-PCR methods. Results: No R122H mutation was found in the PRSS1 gene, and N29I mutation was detected in 7.7% of CP patients. A N29I mutation was observed in 3.9% of patients with alcohol-related pancreatitis (ACP). A total of 5.8% of CP patients were identified with the N34S mutation. Genotype MS, SS and MZ were detected in 18.3, 3.8 and 1.3% of CP patients, respectively. Conclusion: The percentage of N29I mutations in ACP patients was higher than that reported in other studies, while the percentage of N34S and AAT mutations in ACP and idiopathic CP patients was similar.     

Hereditary pancreatitis

Hereditary pancreatitis is an autosomal dominant condition, which results in recurrent attacks of acute pancreatitis, progressing to chronic pancreatitis often at a young age. The majority of patients with hereditary pancreatitis express one of two mutations (R122H or N29I) in the cationic trypsinogen gene (PRSS1 gene). It has been hypothesised that one of these mutations, the R122H mutation causes pancreatitis by altering a trypsin recognition site so preventing deactivation of trypsin within the pancreas and prolonging its action, resulting in autodigestion. Families with these two mutations have been identified in many countries and there are also other rarer mutations, which have also been linked to hereditary pancreatitis. Patients with hereditary pancreatitis present in the same way as those with sporadic pancreatitis but at an earlier age. It is common for patients to remain undiagnosed for many years, particularly if they present with non-specific symptoms. Hereditary pancreatitis should always be considered in patients who present with recurrent pancreatitis with a family history of pancreatic disease. If patients with the 2 common mutations are compared, those with the R122H mutation are more likely to present at a younger age and are more likely to require surgical intervention than those with N29I. Hereditary pancreatitis carries a 40 % lifetime risk of pancreatic cancer with those patients aged between 50 to 70 being most at risk in whom screening tests may become important.     

Three cases of hereditary pancreatitis in two households in the same family associated with R122H mutation in cationic trypsinogen gene]

Hereditary pancreatitis is a rare, autosomal dominant, inherited disease characterized by recurrent attacks of acute pancreatitis with the development of chronic pancreatitis and an increased risk of pancreatic cancer. R122H or N29I mutation in cationic trypsinogen (protease serine 1, PRSS1) gene causes hereditary pancreatitis. R122H mutation is the most common mutation that causes pancreatitis by preventing deactivation of trypsin within the pancreas and prolonging its action. Three members of the family, the patient, her elder son, and her niece experienced recurrent attacks of pancreatitis. We analyzed five exons of the PRSS1 gene in DNA samples of five family members including her husband and younger son who were asymptomatic. We found out that four members of the family, the patient, her two sons, and her niece, had R122H mutation in the exon 3 of PRSS1 gene. Finally, we diagnosed hereditary pancreatitis in two households in the same family.     

Epidemiology of pancreatic diseases in Lüneburg county: A study in a defined German population

Background/Aims: Worldwide, the incidence of pancreatic cancer is very well known, that of acute pancreatitis and chronic pancreatitis not. Our study sought to determine the incidence of all three pancreatic diseases in a well-defined population in Germany. Methods: Records of all patients treated for acute (first attacks only) and chronic pancreatitis as well as pancreatic cancer from 1988 to 1995 and who resided in the county of Lüneburg were evaluated. Results: The crude incidence rates for acute pancreatitis, chronic pancreatitis and pancreatic cancer per 100,000 inhabitants/year were 19.7, 6.4, and 7.8. In acute and chronic pancreatitis the male gender dominated, whereas in pancreatic carcinoma the gender ratio was almost even. Peak incidence for acute pancreatitis was in the age group of 35–44 years, for chronic pancreatitis 45–54, and for pancreatic cancer 6575. Etiology of acute pancreatitis was biliary in 40%, alcohol abuse in 32%, unknown in 20%, and other in 8% of the patients. In chronic pancreatitis alcohol abuse was the etiology in 72% and unknown (idiopathic) in 28%. Conclusion: For the first time, epidemiological data obtained in a well-defined German population are being published relating to all three pancreatic diseases: acute pancreatitis (incidence rate, etiology and severity), chronic pancreatitis (incidence rate and etiology), and pancreatic carcinoma (incidence rate). A peak incidence of chronic pancreatitis occurring in an age group 10 years older than the peak age group for acute pancreatitis suggests that chronic pancreatitis develops during this time-frame following first attacks of acute pancreatitis.     

A Thai family with hereditary pancreatitis and increased cancer risk due to a mutation in PRSS1 gene

AIM: To investigate mutation of serine protease 1-cationic trypsinogen (CT, PRSS1) gene in members of a Thai family with hereditary pancreatitis and pancreatic cancer. METHODS: Polymerase chain reaction and direct sequencing were performed to analyze the PRSS1 gene in two members of the family affected by pancreatitis. Allele specific amplification (ASA) method was then developed to detect the mutation of the PRSS1 gene in all available members of the family and normal control subjects. RESULTS: A cytosine (C) to thymine (T) mutation at position 2441 (g.2441C>T) of the PRSS1 gene, which results in a substitution of arginine by cysteine at position 116 (R116C) of CT, was identified by direct sequencing in both clinically affected members of the family but was not found in the unaffected member. This mutation, which might be arising from deamination of methylated cytosine in CpG dinucleotide of codon 116 (CGT>TGT), was also detected by the ASA method in the two affected members and a proband's brother but was not observed in unaffected members and 54 normal control subjects. CONCLUSION: Autosomal dominant pancreatitis with increased cancer risk in the studied Thai family is most likely due to missense (R116C) mutation in the PRSS1 gene.     

PRSS1_p.Leu81Met mutation results in autoimmune pancreatitis

AIM: To describe protease serine 1 (PRSS1) gene mutations in patients with autoimmune pancreatitis (AIP) and the clinical features of AIP. METHODS: Fourteen patients with AIP, 56 with other chronic pancreatitis, 254 with pancreatic cancer and 120 normal controls were studied. The mutations and polymorphisms of four genes involved with pancreatitis or pancreatic cancer, PRSS1 , SPINK1 , CFTR and MEN1 , were sequenced. The pathogenic mechanism of AIP was investigated by comparing the wild-type expression system with the p.81Leu→Met mutant expression system. RESULTS: Two novel mutations (p.81Leu→Met and p.91Ala→Ala) were found in PRSS1 gene from four patients with AIP. PRSS1_p.81Leu→Met mutation led to a trypsin display reduction (76.2%) combined with phenyl agarose (Ca2+ induced failure). Moreover, the ratio of trypsin/amylase in patients with AIP was higher than in the patients with pancreatic cancer and other pancreatitis. A large number of lymphocytes and plasma cells were found in the bile ducts accompanied by hyperplasia of myofibroblasts. CONCLUSION: Autoimmune pancreatitis may be related to PRSS1 gene mutations.     

Clinical usefulness of K-ras gene mutation detection and cytology in pancreatic juice in the diagnosis and screening of pancreatic cancer.

BACKGROUND: The significance of K-ras codon 12 mutation in pancreatic juice is still unclear. Although considerable controversy surrounds this question, the diagnostic utility of K-ras in patients with clinical suspicion of pancreatic cancer (PC) and in PC-risk patients remains unknown. OBJECTIVE: To study prospectively the utility of the K-ras gene mutation and cytology in the diagnosis and screening of PC, and to assess its contribution to clinical decision making. METHODS: Pancreatic juice samples obtained from 90 patients were evaluated prospectively. Group I (n = 40) comprised patients with clinical suspicion of PC; group II (n = 50) comprised 49 patients with chronic pancreatitis and one patient proceeding from a PC family screening. The K-ras mutation was detected by means of artificial restriction fragment length polymorphisms (RFLP) in DNA after polymerase chain reaction (PCR) amplification. RESULTS: In group I, of those patients with a definitive diagnosis of PC, malignant cells were found in 27% and K-ras mutation in 44%. In five cases, molecular analysis contributed to diagnosis (4/11 with negative cytology and 1/2 with insufficient cytological material). K-ras mutation revealed an early tumour in one patient, and was the only sample available for diagnosis in another. In group II, the K-ras gene mutation was detected in 8/49 patients (16%) with chronic pancreatitis, one of whom developed PC (2%). CONCLUSIONS: K-ras mutation analysis of pancreatic juice may complement cytological evaluation in the diagnosis of PC, in spite of its limited contribution to clinical decision making. The presence of K-ras mutation in chronic pancreatitis classifies a subgroup of PC-risk patients who should be evaluated carefully by long-term follow-up.     

PRSS1 and SPINK1 mutations in idiopathic chronic and recurrent acute pancreatitis

AIM: To identify gene mutations in PRSS1 and SPINK1 in individuals with early onset idiopathic chronic or recurrent acute pancreatitis.METHODS: The cationic trypsinogen gene (PRSS1; exons 2 and 3) and the serine protease inhibitor Kazal 1 gene (SPINK1; exon 3) were selectively amplified and sequenced from blood samples of 19 patients admitted to the Pancreas Clinic at our institution with chronic pancreatitis and/or idiopathic recurrent acute pancreatitis that were diagnosed or with onset before age 35. Fifty healthy volunteers served as controls. Whole blood samples were collected and gene specific sequences were amplified by polymerase chain reaction (PCR). All PCR products were subsequently sequenced in order to identify the presence of any mutations.RESULTS: Nineteen patients with pancreatitis (14 males; median age 24 years, range 15-48 years) were included in this study, of which five showed the presence of gene mutations. Direct sequencing results indicated the presence of two previously unidentified mutations in exon 2 of PRSS1 (V39E and N42S) in two patients with recurrent acute pancreatitis. Two cases had the N34S SPINK1 mutation. Analysis of the relatives of one patient homozygous for this mutation showed that five of the six family members carried the N34S SPINK1 mutation. Of these members, three were healthy heterozygous carriers and two were homozygotes (one sibling had diabetes, the other was healthy). Another patient was heterozygous for a novel SPINK1 mutation located on exon 3 (V46D). All members from this patient’s family had normal genotypes, indicating that it was a de novo mutation. No mutations in either gene were present in the control subjects.CONCLUSION: Two novel PRSS1 mutations and one novel SPINK1 mutation were identified in Mexican patients with early onset idiopathic recurrent acute pancreatitis.     

p53 and K-ras mutations in pancreatic juice samples from patients with chronic pancreatitis

Background: Mutations in p53 and ras genes are frequent in pancreatic carcinoma. Several ras mutations are consistently detected in the pancreatic juice from patients with chronic pancreatitis. The p53 gene mutations have been detected occasionally in chronic pancreatitis tissue. It was the aim of this study to evaluate the presence and clinical significance of p53 and ras mutations in clinical pancreatic juice samples from patients with chronic pancreatitis. Methods: Pancreatic juice was obtained from 66 patients with chronic pancreatitis and no evidence of pancreatic carcinoma (51 men, 15 women; age 17-86 years [mean 49.6 ± 12.9]). Patients were followed prospectively for 26 ± 3 (4-54) months. Detection of p53 gene mutations was by temperature gradient gel electrophoresis (TGGE) and single strand conformation polymorphism (SSCP) for exons 5-8. Analysis of ras mutations was performed by SSCP/polymerase chain reaction, restriction fragment length polymorphism/polymerase chain reaction. All mutations were confirmed by sequencing. Results: Five of 66 (7.5%) pancreatic juice samples contained p53 mutations, and ras mutations were detected in 6 cases (9%). Cytology was negative in all cases. No pancreatic carcinoma developed during follow-up and neither cancer cells nor preneoplastic lesions could be detected histologically in resected specimens. Although no correlation between p53 mutations and duration of pancreatitis or drinking habits was found, K-ras mutations correlated with both heavy smoking and severity of the disease. Conclusion: p53 and ras mutations can be detected in a minority of pancreatic juice samples from patients with chronic pancreatitis in the absence of malignancy. (Gastrointest Endosc 2001;53:734-43.)     

Genetic mutations in exons 3 and 4 of the pancreatic secretory trypsin inhibitor in patients with pancreatitis

Purpose. We hypothesized that mutations in the pancreatic secretory trypsin inhibitor (PSTI) gene could promote autodigestion, leading to acute or chronic pancreatitis. Our investigation involved mutation analysis of the PSTI gene in patients with acute or chronic pancreatitis. Methods. Mutation analysis for the PSTI gene was performed in patients with acute or chronic pancreatitis. Unrelated healthy volunteers and family members of a chronic pancreatitis patient with point mutations in the PSTI gene were also analyzed. Results. Two types of single-point mutation in the PSTI gene were observed in one patient with chronic pancreatitis: ³⁴Asn (AAT)-to-Ser (AGT) (101 A > G N34S: N34S) in exon 3, and ⁶⁷Arg (CGC)-to-Cys (TGC) (199 C > T R67C: R67C) in exon 4. No mutations with amino-acid substitution were found in other patients or in the volunteer group. In the patient with the PSTI gene mutations, no additional mutations were observed in the cationic trypsinogen gene. The family study revealed that the mother and a maternal uncle were homozygotes for the N34S mutation, while the father and brother were compound heterozygotes for the N34S and R67C mutations. The uncle (N34S/N34S) showed clinical manifestations of pancreatitis, but the other family members did not. Conclusions. The N34S mutation may cause a predisposition to pancreatitis, with incomplete penetrance. However, with the limited information available, it is not known whether the R67C mutation promotes pancreatitis. Received: November 17, 2000 / Accepted: March 2, 2001