Multiple Endocrine Neoplasia Type 1 (MEN1) Sequencing and Deletion/Duplication

Background Information for Multiple Endocrine Neoplasia Type 1 (MEN1) Sequencing and Deletion/Duplication:
Characteristics: Multiple Endocrine Neoplasia Type 1 (MEN1) syndrome can include multiple endocrine and non-endocrine tumors. Common MEN1-related endocrine tumors include parathyroid (90-95 percent), pancreatic islets (30-80 percent), and pituitary (15-90 percent). Non-endocrine tumors include facial angiofibroma, collagenoma, lipoma, meningioma, ependymoma, and leiomyoma. Primary hyperparathyroidism is the most common and often the first manifestation of MEN1. High mortality rates occur in persons with gastrinoma and carcinoid tumors.  
Incidence: Approximately 1 in 30,000.
Inheritance: Autosomal dominant.
Penetrance: Approximately 50 percent by age 20 and 95 percent by age 40.
Cause: Pathogenic MEN1 gene mutations.
Clinical Sensitivity: Approaches 94 percent.
Methodology: Bidirectional sequencing of the entire coding region and intron-exon boundaries of the MEN1 gene. Multiplex ligation-dependent probe amplification (MLPA) to detect large MEN1 coding region deletions/duplications.
Analytical Sensitivity and Specificity: Approximately 98 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations and deep intronic mutations will not be detected.  The breakpoints of large deletions/duplications will not be determined. Mutations in genes other than MEN1 are not evaluated. This assay is not designed to detect somatic variants associated with malignancy. Interpretation of this test result may be impacted if the patient has had an allogeneic stem cell transplantation.