Hereditary Pancreatitis is a rare inherited condition characterized by recurrent episodes of acute pancreatitis attacks. In about half of these cases the problem progresses to chronic pancreatitis, which is severe scarring of the pancreas. Laboratory tests performed during an attack usually detect high blood levels of amylase and lipase, which are enzymes released from the pancreas. The first attack typically occurs within the first two decades of life, but can begin at any age. In the United States, it is estimated that at least 1,000 individuals are affected with hereditary pancreatitis.
Symptoms of Hereditary Pancreatitis
Patients with hereditary pancreatitis may have chronic abdominal pain, diarrhea, nausea, vomiting, malnutrition, or diabetes.
Diagnosis of Hereditary Pancreatitis
The diagnosis of hereditary pancreatitis by genetic testing can be a valuable tool. Hereditary pancreatitis is a progressive disease with a high risk of permanent problems.
It is not uncommon for HP to manifest during childhood. Several mutations in the cationic trypsinogen (PRSS1) gene on chromosome 7 are clearly associated with HP. Mutations in PRSS1 have been either shown or hypothesized to increase activation or retard degradation of trypsin, an important digestive enzyme, increased levels of which are thought to lead to pancreatic injury. Recurrent attacks of acute pancreatitis often lead to complications of chronic pancreatitis including failure of exocrine digestive functions, diabetes mellitus, Pseudocysts, and increased risk of pancreatic cancer. Individuals carrying these mutated genes can be identified before pancreatitis begins, and may aid in the design of strategies for preventing or controlling the development of the clinical manifestations of the disease.
HP demonstrates an interesting mechanism of inheritance. It is transmitted in an autosomal dominant fashion, but with incomplete penetrance. Studies have shown that 80% of individual inheriting a mutant PRSS1 gene will develop pancreatitis but another 20% carrying the mutation will be spared. Individual who do not manifest pancreatitis may still transmit a mutant gene to offspring who may exhibit the disease.
The test employs PCR amplification of genomic DNA isolated from patient white blood cells for these two regions of the PRSS1 gene followed by restriction endonuclease digestion and gel electrophoresis to identify normal and heterozygous individuals in each region tested. A customized report is generated which takes into account family history (if provided) and the inheritance pattern of this disorder.
Causes, incidence, and risk factors of Hereditary Pancreatitis
Hereditary Pancreatitis is a genetic disorder, which means that it is usually passed from one generation to the next.
The symptoms of Hereditary Pancreatitis are caused by a change to a specific gene. Genes are the packages of information that control how our bodies look and function. A single gene appears to be involved in 60-75% of hereditary pancreatitis families. This gene produces the "cationic trypsinogen" enzyme, which breaks down the proteins present in the foods we eat. (In some research papers cationic trypsinogen is called PRSS1).
When a change to a gene occurs, the gene may no longer function properly. These gene changes are called mutations. Currently, there are two common, and more than 6 uncommon cationic trypsinogen gene mutations that are associated with hereditary pancreatitis. The major mutations are known as cationic trypsinogen "R122H", "N29I".
Families with Hereditary Pancreatitis might carry one of these mutations, but usually not more than one type of mutation. It is also possible that a family with a strong history of Hereditary Pancreatitis may not carry any of the currently known mutations. For this reason, it is believed that additional genes and mutations that cause Hereditary Pancreatitis are awaiting discovery.
Hereditary Pancreatitis has also been linked to an increased lifetime risk of pancreatic cancer. Pancreatic cancer is the 4th most leading cause of cancer deaths among Americans.
Treatment of Hereditary Pancreatitis
The treatment for hereditary pancreatitis depends on the symptoms. However, the primary treatment focuses on pain control and pancreatic enzyme replacement. Surgery may be indicated to improve symptoms. Removal of the entire pancreas can be performed to eliminate the source of the problem, however in most cases this results in permanent insulin-dependent diabetes.
Prognosis of Hereditary Pancreatitis
As with any chronic disease, the effects may last for months or years. Follow your physician's suggested diet, prescribed medications, and other medical orders.
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