Overview
Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG (myelin-associated glycoprotein) antibodies is a rare neurological condition that affects the peripheral nerves — the nerves outside the brain and spinal cord. In this disease, the body produces an abnormal protein called IgM monoclonal immunoglobulin, which is made by a small clone of immune cells. This IgM protein specifically targets MAG, a component of the protective coating (myelin sheath) that surrounds nerves. When these anti-MAG antibodies attack the myelin, the nerves gradually lose their ability to send signals properly, especially in the hands and feet. The condition typically begins slowly in older adults, usually after age 50. The most common early symptoms include numbness, tingling, and loss of balance, starting in the feet and gradually moving upward. Patients often notice difficulty with fine motor tasks like buttoning shirts, and they may develop an unsteady gait or tremor in the hands. The disease tends to progress slowly over years, but it can significantly affect quality of life. Treatment remains challenging. The underlying IgM-producing clone is usually a low-grade lymphoproliferative disorder, most often called Waldenström macroglobulinemia or IgM monoclonal gammopathy of undetermined significance (MGUS). Treatment options include rituximab (a medication that targets the immune cells producing the harmful antibody), plasma exchange, and other immunosuppressive therapies. However, responses are often partial, and no single treatment has been proven to reliably halt or reverse the nerve damage. Research is ongoing to find more effective therapies.
Also known as:
Key symptoms:
Numbness and tingling in the feet and handsLoss of balance and unsteady walkingDifficulty feeling vibrations or light touchTremor in the handsDifficulty with fine motor tasks like writing or buttoning clothesWeakness in the lower legs and feetCramping or aching in the legsCold or painful sensations in the extremitiesFoot drop in advanced casesGradual loss of reflexesFatigueDifficulty walking on uneven surfaces
Sporadic
Usually appears on its own, not inherited from a parent
Late onset
Begins later in life, typically after age 50
FDA & Trial Timeline
1 eventCentre Hospitalier Universitaire de Saint Etienne — PHASE3
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG.
1 clinical trialare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG.
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Start the conversation →Latest news about Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG
Disease timeline:
New recruiting trial: Rituximab Therapy in Anti-Myelin Associated Glycoprotein Patients With Characteristics of Good Responders
A new clinical trial is recruiting patients for Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG
Caregiver Resources
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Family & Caregiver Grants
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Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.How high are my anti-MAG antibody levels, and what does that mean for my prognosis?,Is my underlying IgM-producing blood disorder something that needs treatment on its own?,Would rituximab be appropriate for me, and what are the expected benefits and risks?,How often should I have blood tests and nerve conduction studies to monitor my condition?,What physical therapy or rehabilitation programs would help me maintain my function?,Are there any clinical trials I might be eligible for?,What signs of worsening should prompt me to contact you urgently?
Common questions about Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG
What is Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG?
Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG (myelin-associated glycoprotein) antibodies is a rare neurological condition that affects the peripheral nerves — the nerves outside the brain and spinal cord. In this disease, the body produces an abnormal protein called IgM monoclonal immunoglobulin, which is made by a small clone of immune cells. This IgM protein specifically targets MAG, a component of the protective coating (myelin sheath) that surrounds nerves. When these anti-MAG antibodies attack the myelin, the nerves gradually lose their ability to send signals pr
How is Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG inherited?
Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG typically begin?
Typical onset of Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG is late onset. Age of onset can vary across affected individuals.
Are there clinical trials for Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG?
Yes — 1 recruiting clinical trial is currently listed for Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG?
3 specialists and care centers treating Polyneuropathy associated with IgM monoclonal gammopathy with anti-MAG are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.