MEN1 is a ‘tumour protection’ gene that helps to protect against tumours developing in the body, particularly within the endocrine glands which are involved in making hormones. If a tumour develops in the endocrine glands, extra hormones can be released into the blood causing many different symptoms throughout the body.
Everyone has two MEN1 genes (one from their mother, and one from their father). If one of the genes is not working, this is known as having a faulty MEN1 gene, or having a MEN1 mutation. People with a faulty MEN1 gene are known to have Multiple Endocrine Neoplasia type 1.