The PRSS1 c.623G>C (p.G208A) mutation is the most common PRSS1 mutation in Korean children with hereditary pancreatitis

Clinical interpretation of PRSS1 variants in patients with pancreatitis

Since the description of the PRSS1 gene encoding the cationic trypsinogen as being involved in dominant hereditary pancreatitis, more than 50 PRSS1 variants have been reported. Among the PRSS1 variants that have been classified as pathogenic, some have a high penetrance and others have a low penetrance. Assessing the clinical relevance of PRSS1 variants is often complicated in the absence of functional evidence and interpretation of rare variants is not very easy in clinical practice. The aim of this study was to review the different variants identified in the PRSS1 gene and to classify them according to their degree of deleterious effect. This classification was based on the results of several in vitro experiments and on population data, in comparing the allelic frequency of each variant in patients with pancreatitis and in unaffected individuals. This review should help geneticists and clinicians in charge of patient's care and genetic counseling to interpret molecular results.

Pancreaticopleural fistula in children with chronic pancreatitis: a case report and literature review

BACKGROUND

Pancreaticopleural fistula (PPF) is a very rare and critical complication of pancreatitis in children. The majority of publications relevant to PPF are case reports. No pooled analyses of PPF cases are available. Little is known about the pathogenesis and optimal therapeutic schedule. The purpose of this study was to identify the pathogenesis and optimal therapeutic schedule of PPF in children.

CASE PRESENTATION

The patient was a 13-year-old girl who suffered from intermittent chest tightness and dyspnea for more than 3 months; she was found to have chronic pancreatitis complicated by PPF. The genetic screening revealed SPINK1 mutation. She was treated with endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic retrograde pancreatic drainage (ERPD); her symptoms improved dramatically after the procedures.

CONCLUSIONS

PPF is a rare pancreatic complication in children and causes significant pulmonary symptoms that can be misdiagnosed frequently. PPF in children is mainly associated with chronic pancreatitis (CP); therefore, we highlight the importance of genetic testing. Endoscopic treatment is recommended when conservative treatment is ineffective.

Targeted Gene Next-Generation Sequencing in Chinese Children with Chronic Pancreatitis and Acute Recurrent Pancreatitis

OBJECTIVE

To identify causal mutations in certain genes in children with acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP).

STUDY DESIGN

After patients were enrolled (CP, 55; ARP, 14) and their clinical characteristics were investigated, we performed next-generation sequencing to detect nucleotide variations among the following 10 genes: cationic trypsinogen protease serine 1 (PRSS1), serine protease inhibitor, Kazal type 1 (SPINK1), cystic fibrosis transmembrane conductance regulator gene (CFTR), chymotrypsin C (CTRC), calcium-sensing receptor (CASR), cathepsin B (CTSB), keratin 8 (KRT8), CLAUDIN 2 (CLDN2), carboxypeptidase A1 (CPA1), and ATPase type 8B member 1 (ATP8B1). Mutations were searched against online databases to obtain information on the cause of the diseases. Certain novel mutations were analyzed using the SIFT2 and Polyphen-2 to predict the effect on protein function.

RESULTS

There were 45 patients with CP and 10 patients with ARP who harbored 1 or more mutations in these genes; 45 patients had at least 1 mutation related to pancreatitis. Mutations were observed in the PRSS1, SPINK1, and CFTR genes in 17 patients, the CASR gene in 5 patients, and the CTSB, CTRC, and KRT8 genes in 1 patient. Mutations were not found in the CLDN, CPA1, or ATP8B1 genes. We found that mutations in SPINK1 may increase the risk of pancreatic duct stones (OR, 11.07; P = .003). The patients with CFTR mutations had a higher level of serum amylase (316.0 U/L vs 92.5 U/L; P = .026).

CONCLUSION

Mutations, especially those in PRSS1, SPINK1, and CFTR, accounted for the major etiologies in Chinese children with CP or ARP. Children presenting mutations in the SPINK1 gene may have a higher risk of developing pancreatic duct stones.

Genetic risk in chronic pancreatitis: the misfolding-dependent pathway

PURPOSE OF REVIEW

Genetic risk in chronic pancreatitis is partly due to mutations that cause misfolding of digestive enzymes and elicit endoplasmic reticulum stress. This review examines recent developments in this concept.

RECENT FINDINGS

The best characterized misfolding variants in the highly expressed digestive proteases cationic trypsinogen (PRSS1) and carboxypeptidase A1 (CPA1) are strong, causative risk factors for chronic pancreatitis and may be associated with autosomal dominant hereditary pancreatitis.

SUMMARY

Properties of misfolding digestive enzyme mutants indicate that endoplasmic reticulum stress is a highly relevant pathological mechanism and a potential therapeutic target in chronic pancreatitis.

PRSS1, SPINK1, CFTR, and CTRC Pathogenic Variants in Korean Patients With Idiopathic Pancreatitis

BACKGROUND

This study aimed to identify pathogenic variants of PRSS1, SPINK1, CFTR, and CTRC genes in Korean patients with idiopathic pancreatitis.

METHODS

The study population consisted of 116 Korean subjects (65 males, 51 females; mean age, 30.4 yr, range, 1-88 yr) diagnosed with idiopathic chronic pancreatitis (ICP), idiopathic recurrent acute pancreatitis (IRAP), or idiopathic acute pancreatitis (IAP). We analyzed sequences of targeted regions in the PRSS1, SPINK1, CFTR, and CTRC genes, copy numbers of PRSS1 and SPINK1, and clinical data from medical records.

RESULTS

We identified three types of pathogenic PRSS1 variants in 11 patients, including p.N29I (n=1), p.R122H (n=1), and p.G208A (n=9). Sixteen patients exhibited heterozygous pathogenic variants of SPINK1, including c.194+2T>C (n=12), p.N34S (n=3), and a novel pathogenic splicing variation c.194+1G>A. A heterozygous CFTR p.Q1352H pathogenic variant was detected in eight patients. One patient carried a heterozygous CTRC p.P249L pathogenic variant, which is a known high-risk variant for pancreatitis. All patients had normal PRSS1 and SPINK1 gene copy numbers. Weight loss occurred more frequently in patients carrying the p.G208A pathogenic variant, while pancreatic duct stones occurred more frequently in patients with the c.194+2T>C pathogenic variant.

CONCLUSIONS

Pathogenic variants of PRSS1, SPINK1, and CFTR were associated with idiopathic pancreatitis, while pathogenic variants of CTRC were not. Copy number variations of PRSS1 and SPINK1 were not detected.