Muckle-Wells Syndrome (MWS): Fact Sheet
TOPICS:
What It Is
Causes and Symptoms
Incidence and Prevalence
Living with MWS
Diagnosis & Treatment
References
What It Is
MWS is one of the cryopyrin associated periodic syndromes (CAPS) caused by mutations in the CIAS1/NALP3 gene. These syndromes are characterized by intermittent attacks of fever associated with rash and joint pain.(2)
Individuals with MWS often have episodic fever, chills, and painful joints. Sometimes these symptoms are exacerbated by cold similar to the related condition FCAS, but can also be triggered by other stimuli. In most cases, Muckle-Wells syndrome (MWS) patients develop progressive hearing loss. In some MWS cases amyloidosis develops later in life, a disease in which an abnormal accumulation of the protein amyloid occurs in a patient's tissues and organs.(1)
Causes and Symptoms
MWS is caused by a mutation in a gene identified as the cold-induced auto-inflammatory syndrome 1 (CIAS1) gene. The mutation in the CIAS1 gene causes increased activity of cryopyrin, a protein that regulates inflammation in the body. The increased activity of cryopyrin results in an overproduction of a protein known as interleukin 1ß, which leads to symptoms of inflammation such as fever and joint pain.(3,4)
Common symptoms of MWS include recurrent rashes beginning in infancy or early childhood, periodic fevers, joint pain (usually with no apparent changes in tissue and cartilage), recurrent conjunctivitis (the inflammation of the outer most layer of the eye causing redness, discomfort and discharge from the eye), progressive hearing loss and amyloidosis. Symptoms can vary between individuals and the CIAS1 gene mutation is passed on in an autosomal dominant manner. The mutation also can occur spontaneously.
Symptoms can be triggered by cold exposure, but also stress or exercise. Episodes generally last between 24 to 48 hours.(5)
Incidence and Prevalence
Since MWS is a newly discovered condition, the actual incidence and prevalence of the disease is difficult to determine.
Living with MWS
The rashes and pain caused by MWS can sometimes be quite debilitating as episodes occur throughout one's life and are often accompanied by a low-grade fever.(6)
Diagnosis & Treatment
Diagnosis of MWS is determined through an evaluation of a patient's symptoms. Confirmation of the diagnosis is achieved through genetic testing and the identification of a CIAS1 mutation.
To correct the hearing loss that often occurs, hearing aids may be used. There are no medications currently indicated for the treatment of MWS. In recent clinical studies, investigational interleukin-1 inhibitors had encouraging preliminary results in addressing the inflammatory features of the conditions in study patients, but these product candidates have not been approved by the FDA for the treatment of MWS.(6)