Analytic validity refers to how well a genetic assessment measures the property or characteristic it is intended to measure. In the case of family history, analytic validity refers to the accuracy of the reported family history information. In the case of a test for a specific mutation, analytic validity refers to the accuracy of a genetic test in identifying the presence or absence of the mutation. The technical accuracy and reliability of the testing procedure and the quality of the laboratory processes (including specimen handling) affect the analytic validity of a genetic assessment.
Assessing analytic validity is complex for some genetic tests. For example, in a panel test, which is designed to evaluate a particular set of mutations (e.g., the Ashkenazi founder mutations in the BRCA1 and BRCA2genes), the analytic validity of the different components of the test may vary. Some genetic tests involve evaluating the DNA sequence of portions of a gene to determine whether any mutations are present (including mutations not previously identified). The sensitivity and specificity of these sequencing tests may vary with the laboratory techniques employed, the proportion of the gene tested, and the structural nature of the mutations present in the gene.
Pheochromocytomas and extra-adrenal paragangliomas are rare tumors arising from neural crest tissue that develops into sympathetic and parasympathetic paraganglia throughout the body.
The most recent World Health Organization classification utilizes the term pheochromocytoma exclusively for tumors arising from the adrenal medulla, and the term extra-adrenal paraganglioma for similar tumors that arise from other locations.
Incidence and Mortality
The incidence of pheochromocytoma is 2...