Hereditary pancreatitis | |
---|---|
This condition is inherited in an autosomal dominant manner |
Hereditary pancreatitis (HP) is an inflammation of the pancreas due to genetic causes. It was first described in 1952 by Comfort and Steinberg [1] but it was not until 1996 that Whitcomb et al [2] isolated the first responsible mutation in the trypsinogen gene ( PRSS1 ) on the long arm of chromosome seven (7q35).
The term "hereditary pancreatitis" is used when a genetic biomarker is identified, and "familial pancreatitis" otherwise. [3]
HP is characterised by attacks of epigastric pain, which are often associated with nausea and vomiting. Symptoms may start shortly after birth but onset varies periodically, with some patients not exhibiting symptoms until adulthood. There is usually progression to chronic pancreatitis with endocrine and exocrine failure and a mortally increased risk of pancreatic cancer. Lifetime risk of cancer has been variously calculated as 35–54% [4] [5] [6] to the age of 75 years and screening for early pancreatic cancer is being offered to HP sufferers on a scientific basis. [7] Some patients may choose to have their pancreas surgically removed to prevent pancreatic cancer from developing in the future. [8]
The epidemiology of HP follows a similar pattern to alcohol-associated chronic pancreatitis, but there are important differences. For example, HP typically has an earlier age of pancreatitis onset; although malabsorption and diabetes mellitus occur at a later stage in the disease progression. [5]
The vast majority of the cases of HP are caused by substitutions, at base 365 (c.365G>A) and base 86 of the cDNA (c.86A>T) on the PRSS1 gene. The nucleotide substitutions were discovered in the late 1990s by classical linkage analysis [2] [9] and are now known as p.R122H and p.N29I respectively, according to the amino acid substitution and position in the protein sequence.
These mutations are rarely identified in general screens of patients with idiopathic disease [10] [11] [12] [13] and the phenotype of p.R122H and p.N29I is now well characterised [4] [5] [6] with the p.A16V mutation recently characterised for the first time. [14] There are many other rare mutations or polymorphisms of PRSS1 which remain less well understood [15] [16] and not all HP families have had the responsible genetic mutation identified.
The mechanism by which these genetic mutations cause pancreatitis is not yet known; but is likely to be the result of increased autoactivation [17] or reduced deactivation [18] of trypsinogen. However, a novel mechanism has recently been identified in a p.R116C kindred. [19]
Families are defined as having HP, [5] if the phenotype is consistent with highly penetrant autosomal dominant inheritance. In simple terms, this would require two or more first degree relatives (or three or more second degree relatives) to have unexplained recurrent-acute or chronic pancreatitis in two or more generations. It is an autosomal dominant disease with penetrance that is generally accepted to be ≈80%. [1] [20]
Treatment of HP resemble that of chronic pancreatitis of other causes. Treatment focuses on enzyme and nutritional supplementation, pain management, pancreatic diabetes, and local organ complications, such as pseudocysts, bile duct or duodenal obstruction.(PMC1774562)[ citation needed ]
A 2009 study which followed 189 patients found no excess mortality despite the increased risk of pancreatic cancer. [21]
Pancreatitis is a condition characterized by inflammation of the pancreas. The pancreas is a large organ behind the stomach that produces digestive enzymes and a number of hormones. There are two main types: acute pancreatitis, and chronic pancreatitis.
Pancreatic cancer arises when cells in the pancreas, a glandular organ behind the stomach, begin to multiply out of control and form a mass. These cancerous cells have the ability to invade other parts of the body. A number of types of pancreatic cancer are known.
Acute pancreatitis (AP) is a sudden inflammation of the pancreas. Causes, in order of frequency, include: a gallstone impacted in the common bile duct beyond the point where the pancreatic duct joins it; heavy alcohol use; systemic disease; trauma; and, in minors, mumps. Acute pancreatitis may be a single event; it may be recurrent; or it may progress to chronic pancreatitis.
Chronic pancreatitis is a long-standing inflammation of the pancreas that alters the organ's normal structure and functions. It can present as episodes of acute inflammation in a previously injured pancreas, or as chronic damage with persistent pain or malabsorption. It is a disease process characterized by irreversible damage to the pancreas as distinct from reversible changes in acute pancreatitis. Tobacco smoke and alcohol misuse are two of the most frequently implicated causes, and the two risk factors are thought to have a synergistic effect with regards to the development of chronic pancreatitis. Chronic pancreatitis is a risk factor for the development of pancreatic cancer.
Trypsinogen is the precursor form of trypsin, a digestive enzyme. It is produced by the pancreas and found in pancreatic juice, along with amylase, lipase, and chymotrypsinogen. It is cleaved to its active form, trypsin, by enteropeptidase, which is found in the intestinal mucosa. Once activated, the trypsin can cleave more trypsinogen into trypsin, a process called autoactivation. Trypsin cleaves the peptide bond on the carboxyl side of basic amino acids such as arginine and lysine.
Hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndrome is an autosomal dominant genetic condition that is associated with a high risk of colon cancer as well as other cancers including endometrial cancer, ovary, stomach, small intestine, hepatobiliary tract, upper urinary tract, brain, and skin. The increased risk for these cancers is due to inherited genetic mutations that impair DNA mismatch repair. It is a type of cancer syndrome. Because patients with Lynch syndrome can have polyps, the term HNPCC has fallen out of favor.
A pancreaticoduodenectomy, also known as a Whipple procedure, is a major surgical operation most often performed to remove cancerous tumours from the head of the pancreas. It is also used for the treatment of pancreatic or duodenal trauma, or chronic pancreatitis. Due to the shared blood supply of organs in the proximal gastrointestinal system, surgical removal of the head of the pancreas also necessitates removal of the duodenum, proximal jejunum, gallbladder, and, occasionally, part of the stomach.
Exocrine pancreatic insufficiency (EPI) is the inability to properly digest food due to a lack or reduction of digestive enzymes made by the pancreas. EPI can occur in humans and is prevalent in many conditions such as cystic fibrosis, Shwachman–Diamond syndrome, different types of pancreatitis, multiple types of diabetes mellitus, advanced renal disease, older adults, celiac disease, IBS-D, IBD, HIV, alcohol-related liver disease, Sjogren syndrome, tobacco use, and use of somatostatin analogues.
Pancreatic diseases are diseases that affect the pancreas, an organ in most vertebrates and in humans and other mammals located in the abdomen. The pancreas plays a role in the digestive and endocrine system, producing enzymes which aid the digestion process and the hormone insulin, which regulates blood sugar levels. The most common pancreatic disease is pancreatitis, an inflammation of the pancreas which could come in acute or chronic form. Other pancreatic diseases include diabetes mellitus, exocrine pancreatic insufficiency, cystic fibrosis, pseudocysts, cysts, congenital malformations, tumors including pancreatic cancer, and hemosuccus pancreaticus.
Probable phospholipid-transporting ATPase IC is an enzyme that in humans is encoded by the ATP8B1 gene. This protein is associated with progressive familial intrahepatic cholestasis type 1 as well as benign recurrent intrahepatic cholestasis.
Microvillus inclusion disease, previously known as Davidson's disease, congenital microvillus atrophy and, less specifically, microvillus atrophy, is a rare genetic disorder of the small intestine that is inherited in an autosomal recessive pattern.
Trypsin-1, also known as cationic trypsinogen, is a protein that in humans is encoded by the PRSS1 gene. Trypsin-1 is the main isoform of trypsinogen secreted by pancreas, the others are trypsin-2, and trypsin-3 (meso-trypsinogen).
Pancreatic secretory trypsin inhibitor (PSTI) also known as serine protease inhibitor Kazal-type 1 (SPINK1) or tumor-associated trypsin inhibitor (TATI) is a protein that in humans is encoded by the SPINK1 gene.
Chymotrypsin C, also known as caldecrin or elastase 4, is an enzyme that in humans is encoded by the CTRC gene.
Ductal cells refer to the epithelial cell lining of the pancreatic duct that deliver enzymes from the acinar cells to the duodenum. They have the essential function of producing bicarbonate-rich (HCO3-) secretion to neutralize stomach acidity. The hormone secretin stimulates ductal cells and is responsible for maintaining the duodenal pH and preventing duodenal injury from acidic chyme. Ductal cells mix their production with acinar cells to make up the pancreatic juice.
The European Registry of Hereditary Pancreatitis and Pancreatic Cancer (EUROPAC) was started by John Neoptolemos and colleagues in 1997 and has become the world’s most extensive study on hereditary pancreatic diseases. It enabled discovery of several genetic characteristics causative for hereditary pancreatitis and familial pancreatic cancer.
A hereditary cancer syndrome is a genetic disorder in which inherited genetic mutations in one or more genes predispose the affected individuals to the development of cancer and may also cause early onset of these cancers. Hereditary cancer syndromes often show not only a high lifetime risk of developing cancer, but also the development of multiple independent primary tumors.
Type 3c diabetes is diabetes that comes secondary to pancreatic diseases, involving the exocrine and digestive functions of the pancreas. It also occurs following surgical removal of the pancreas.
The HFE H63D is a single-nucleotide polymorphism in the HFE gene, which results in the substitution of a histidine for an aspartic acid at amino acid position 63 of the HFE protein (p.His63Asp). HFE participates in the regulation of iron absorption.
Garth David Ehrlich is a molecular biologist, genomic scientist, academic, and author who is most known for his development of the distributed genome hypothesis and bringing the biofilm paradigm to the field of chronic mucosal bacterial diseases. He is a professor of Microbiology and Immunology, and Otolaryngology-Head and Neck Surgery at Drexel University. He is also the founder and executive director of three Research Centers of Excellence: the Center for Genomic Sciences (CGS); the Center for Advanced Microbial Processing (CAMP); and the Center for Surgical Infections and Biofilms. In addition, he serves as the executive director of the Genomics Core Facility and the director of Molecular Pathology within Drexel Medicine Diagnostics and the Sidney Kimmel Cancer Center's Meta-omics Core Facility.