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Health condition

MEN1 syndrome

Multiple endocrine neoplasia type 1 (MEN1) causes tumours of the parathyroid glands, pancreas and pituitary - the 'three Ps' - and lifelong biochemical and imaging surveillance from childhood keeps its complications ahead of trouble.

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against current NHS and UK specialist society guidance at the time of review.

  • 03

    Current for 2026

    Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.

Key facts

The essentials at a glance.

Which gene and test confirm it, who should be tested in the family, and which specialist to see.

  • Caused by MEN1 gene variants; autosomal dominant

  • Primary hyperparathyroidism is near-universal and usually the first sign, often by the twenties or thirties

  • Pancreatic neuroendocrine tumours (gastrinoma, insulinoma, non-functioning) are the main determinant of long-term outlook

  • Annual surveillance combines calcium and hormone blood tests with periodic pancreatic and pituitary MRI

Understanding the condition

What it is and what happens next.

What causes it, how it is confirmed, and the testing and specialist routes available in the UK.

What it is and how it presents

MEN1 is endocrinology's set-piece syndrome: high calcium in anyone under 40 should always raise it, since parathyroid overactivity arrives early and in all four glands, changing the surgical approach entirely from sporadic disease. The pancreas plays the long game - neuroendocrine tumours that surveillance MRI tracks for years, with intervention triggered by size and behaviour - while the pituitary contributes prolactinomas and other adenomas found on scheduled testing rather than late symptoms.

Testing, surveillance and specialist care

Confirmed families are managed through specialist MEN clinics running the annual biochemical panel and interval imaging, with surgery timed and designed for multigland, multifocal disease; genetic testing identifies carriers in childhood so surveillance begins before tumours do, coordinated with counselling across the generations. NHS clinical genetics services carry some of the longest waits in the health service, often many months for a first appointment, whereas private genetic testing and a specialist review can typically be arranged within around two weeks.

Seeing a specialist

Who to see, and how quickly you can be seen.

The specialist for this condition is usually a endocrinologist at a specialist MEN service. Your GP can refer you on the NHS, or you can arrange a private consultation directly.

A quiet reminder

This guide is for information, not medical advice.

Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any emergency symptoms.

Frequently asked

Common questions about MEN1 syndrome.

Quick, plain-English answers to what people ask us most.

  • What is MEN1 syndrome?

    MEN1 (Multiple Endocrine Neoplasia type 1) syndrome is a rare inherited condition causing an increased risk of tumours developing in several endocrine glands, most commonly the parathyroid glands, pancreas, and pituitary gland. Regular lifelong screening helps catch and manage these tumours early.

  • What causes MEN1 syndrome?

    It's caused by mutations in the MEN1 gene, which normally helps suppress abnormal cell growth, inherited in an autosomal dominant pattern. This means an affected parent has a 50% chance of passing the condition to each child.

  • What are the symptoms of MEN1 syndrome?

    Symptoms depend on which glands are affected and can include symptoms of overactive parathyroid glands (such as high calcium levels causing fatigue or kidney stones), pancreatic tumour-related symptoms, or pituitary gland issues affecting various hormones. Symptoms typically develop gradually as tumours grow, often first appearing in early to mid-adulthood.

  • Is MEN1 syndrome dangerous?

    Yes, some associated tumours can be cancerous, particularly certain pancreatic tumours, and the syndrome overall carries an increased lifetime risk of several endocrine cancers, making regular, proactive surveillance essential. Early detection through consistent screening significantly improves outcomes.

  • Is MEN1 syndrome genetic?

    Yes, it's an inherited genetic condition, and genetic testing can confirm the diagnosis and identify at-risk family members who should also undergo testing and, if positive, begin their own regular screening programme. Genetic counselling is an essential part of managing a MEN1 diagnosis for the whole family.

  • Can MEN1 syndrome be cured?

    There's no cure for the underlying genetic condition, but regular, structured surveillance allows early detection and treatment of any tumours that develop, significantly improving outcomes and quality of life. Lifelong monitoring is needed given the ongoing risk of new tumours developing over time.

  • How is MEN1 syndrome managed?

    Management involves a structured, lifelong surveillance programme including regular blood tests and imaging to monitor the parathyroid glands, pancreas, and pituitary gland, with specific treatment (often surgery) for any tumours found. This is usually coordinated through a specialist endocrinology and genetics service.

  • How often is screening needed for MEN1 syndrome?

    Surveillance typically involves annual blood tests and periodic imaging, tailored to individual risk and age, continuing throughout life given the ongoing risk of new tumours developing in any of the affected glands. Your specialist team will provide a personalised, lifelong screening schedule.

  • MEN1 vs MEN2 syndrome — what's the difference?

    MEN1 primarily affects the parathyroid glands, pancreas and pituitary gland, while MEN2 primarily affects the thyroid gland (causing medullary thyroid cancer), adrenal glands, and sometimes parathyroid glands, resulting from mutations in different genes. Genetic testing distinguishes between these related but distinct inherited syndromes, guiding appropriately different surveillance programmes.

  • When should I see a specialist about MEN1 syndrome, and how quickly can I be seen privately?

    A family history of MEN1, or symptoms suggestive of multiple endocrine gland involvement, should prompt endocrinology and genetics referral. Private specialist consultations can typically be arranged within about two weeks, considerably faster than standard NHS waiting times.