The key difference between MEN1 and MEN2 is that MEN 1 (multiple endocrine neoplasia 1) is an inherited genetic disorder that causes tumours in the pituitary gland, parathyroid gland, and the pancreas, while MEN 2 (multiple endocrine neoplasia 2) is an inherited genetic disorder that causes tumours in the thyroid gland, parathyroid gland, or adrenal gland.
The endocrine system is made up of glands and cells that produce hormones and release them into the blood. Multiple endocrine neoplasia (MEN) is an inherited genetic disorder that affects the endocrine system. There are several types of multiple endocrine neoplasia syndromes that cause different types of tumors.
CONTENTS
1. Overview and Key Difference
2. What is MEN1 (Multiple Endocrine Neoplasia 1)
3. What is MEN2 (Multiple Endocrine Neoplasia 2)
4. Similarities – MEN1 and MEN2
5. MEN1 vs MEN2 in Tabular Form
6. Summary – MEN1 vs MEN2
What is MEN1 (Multiple Endocrine Neoplasia 1)?
Multiple endocrine neoplasia 1 (MEN 1) is an inherited genetic disorder that causes tumours in pituitary gland, parathyroid gland, and pancreas. It is sometimes known as Wermer’s syndrome, as it was first described by Paul Wermer in 1954. MEN1 is often caused by a mutation in the MEN1 gene. This gene provides instructions for producing a protein known as menin. The menin protein plays a vital role in keeping cells from growing and dividing too fast. This disorder shows autosomal dominant inheritance.
Figure 01: MEN1 and MEN2
Generally, tumors in the above glands are benign. However, tumor growth in the pituitary gland, parathyroid gland, and pancreas can produce and release excessive hormones that lead to the disease. Excessive hormones can cause a wide variety of signs and symptoms. These signs and symptoms include tiredness, bone, pain, broken bones, kidney stones, and ulcers in the stomach. The diagnosis of this medical condition is normally made through blood tests, imaging testing (MRI, CT scan, PET scan, nuclear medicine scan, endoscopic ultrasound), and genetic testing. The treatments for MENI tumors in the pituitary gland, parathyroid gland, and pancreas include minimally invasive surgeries, chemotherapy, and radiation.
What is MEN2 (Multiple Endocrine Neoplasia 2)?
Multiple endocrine neoplasia 2 (MEN 2) is an inherited genetic disorder that causes tumours in the thyroid gland, parathyroid gland, or adrenal gland. This medical condition is due to a mutation in a gene called RET. RET is a proto-oncogene located on chromosome 10. When mutated, it becomes an oncogene and causes uncontrolled cell growth and tumor formation. MEN2 can be due to inherited mutations as well as sporadic mutations. It is divided into three types: MEN2A, familial modularly thyroid cancer, MEN2B.
The sign and symptoms of this disorder include a lump in front of the neck, difficulty in speaking, difficulty in swallowing, difficulty in breathing, large lymph nodes, throat and neck pain, depression, anxiety, headache, confusion, nausea, lack of appetite, abdominal pain, constipation, bone and joint pain, osteoporosis, high blood pressure, weight loss, tremors, alacrima, mucosal neuromas, eyelid eversion, and scoliosis. The diagnosis is often through family history, physical examination blood tests, X-rays, and genetic testing. The treatment options include removal of the gland through surgery (prophylactic thyroidectomy, removal of parathyroid gland, removal of adrenal gland), laparoscopic laparotomy, calcimimetics (control serum level of parathyroid hormone), alpha-adrenergic blockers, and beta-adrenergic blockers for hypertension
What are the Similarities Between MEN1 and MEN2?
- MEN1 and MEN2 are two types of multiple endocrine neoplasias.
- Both types cause tumors in endocrine glands.
- Both types can occur as inherited conditions or sporadic conditions.
- If inherited, both types show autosomal dominant inheritance patterns.
- In both cases, the tumors may be benign or cancerous.
- These conditions are treatable through surgeries.
What is the Difference Between MEN1 and MEN2?
MEN 1 is an inherited genetic disorder that causes tumours in the pituitary gland, parathyroid gland, and pancreas, while MEN 2 is an inherited genetic disorder that causes tumours in the thyroid gland, parathyroid gland, or adrenal gland. Thus, tthis is the key difference between MEN1 and MEN2. Furthermore, MEN1 is caused by the mutation in the MEN1 gene, while MEN2 is caused by the mutation in the RET gene.
The below infographic presents the differences between MEN1 and MEN2 in tabular form for side by side comparison.
Summary – MEN1 vs MEN2
Multiple endocrine neoplasia is an inherited genetic condition that encompasses several distinct syndromes featuring tumors of endocrine glands. Some tumors are benign, and others are malignant. MEN1 and MEN2 are two types of multiple endocrine neoplasia. MEN 1 is an inherited genetic disorder that causes tumours in the pituitary gland, parathyroid gland, and pancreas while MEN 2 is an inherited genetic disorder that causes tumours in the thyroid gland, parathyroid gland, or adrenal gland. So, this is the key difference between MEN1 and MEN2.
Reference:
1. “Multiple Endocrine Neoplasia Type 1.” National Institute of Diabetes and Digestive and Kidney Diseases, U.S. Department of Health and Human Services.
2. “Multiple Endocrine Neoplasia Type 2.” NORD (National Organization for Rare Disorders).
Image Courtesy:
1. “Multiple endocrine neoplasia” By Mikael Häggström – Own work (CC0) via Commons Wikimedia