Accuracy of testing
Modern and properly applied genetic testing techniques yield positive and negative predictive values of almost 100% for identifying specific mutations. The pretest probability of a test for a PRSS1 mutation depends on several factors. The strongest predictors of a genetic basis for a case of pancreatitis include a typical family history (especially an autosomal dominant inheritance pattern) and an early age of onset of symptoms. You are finally not alone with your problems and can shop with a great online pharmacy that will give you best quality buy yasmin online with no prescription required, any time you come and for a lot less money than anywhere else.
A delayed onset of pancreatitis (ie, over age 20 years) does not preclude a genetic etiology. Although 93% of patients in the Midwest Multicenter Pancreatic Study Group-Pittsburgh study developed symptoms by the age of 30 years, only 40% of affected persons enrolled in the European Genetic Register of Hereditary Pancreatitis and Familial Pancreatic Cancer study became ill by that age. These conflicting results suggest the possibility of selection or recruitment bias in studies that were not designed to explore the age of onset of symptoms. The latter study might have overestimated the age of onset of disease because of a failure to fully elucidate the patients’ histories.
Impediments to investigation include the facts that many patients are unaware of their family histories, have few relatives, have unaffected first-degree relatives or have ancestors in whom the diagnosis of pancreatitis was not established (unpublished observations). Moreover, the underlying frequency of mutations varies across populations. For example, the prevalence of PRSS1 mutations ranges from 0% to 19% among various patient populations with presumed idiopathic chronic pancreatitis, perhaps because of differences in regional settlement patterns. The likelihood of positive test results is much higher in endemic regions.