Insulinoma (insulinoma) - Gen MEN1.  

Insulinoma is a rare neuroendocrine tumor derived from beta cells and characterized by producing insulin in excess and uncontrolled. Insulin secretion in an uncontrolled manner is what gives rise to the symptoms. Only at a late stage of evolution, the tumor also produces symptoms by himself, such as abdominal pain. Signs and symptoms include demonstrations as typical clumsiness, confusion, headache, visual impairment, inconsistent and unusual behavior, unexplained irritation and disorientation, and can lead to seizures and coma. These symptoms are due to the effect of hypoglycemia on the brain and are known by the name neuroglucémicos symptoms.

This process is due to mutations in the MEN1 gene, located on the long arm of chromosome 11 (11q13), encodes a protein called menin that acts as a tumor suppressor, which means that normally prevents cells grow and divide too fast or uncontrolled. Additionally, it is believed that menin protein plays a role in the copy and DNA repair and regulation of cell apoptosis. Menin protein is present in the core of many different cell types and appears to be active at all stages of development. This protein interacts with many other proteins, including several transcription factors, helping to control activity of various genes. Some of these genes likely play a role in cell growth and division. Work is to identify proteins that interact with menin and determine their specific role as a tumor suppressor.

Mutations in the MEN1 gene that result insulinoma, affect the ability of menin protein to interact with other proteins. Without normal function of menin, the cells are likely to divide too often, leading to tumor formation.

This disease is caused by somatic mutations, which means they are acquired throughout a person 's life and not inherited.

Tests in IVAMI: in IVAMI perform detection of mutations associated with insulinoma, by complete PCR amplification of the exons of the MEN1 gene and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).