What is Blau Syndrome?
Blau Syndrome is an extremely rare genetic auto-antiinflammatory disorder which is characterized by recurrent granulomatous uveitis, dermatitis, and symmetric arthritis. It is an autosomal dominant disorder meaning that just one copy of the defective gene from either parent is good enough for a person to inherit the condition. The gene responsible for Blau Syndrome is called NOD2. The primary function of this gene is to provide instructions in the functioning of the immune system of the body. In majority of the cases, the symptoms of Blau Syndrome can be observed in a child by the time he or she is 4 years of age.[1,2,3]
During the initial stages, only the articular and cutaneous manifestations of the disease can be seen but as the condition progresses there will also be ophthalmologic involvement which is the primary symptom of Blau Syndrome. There are also cases where the child will have fever and even other organs like the heart, brain, kidneys, and the GI tract has also been involved. In rare instances, the liver, lymph nodes, spleen, and even the blood vessels get involved in a child with Blau Syndrome.[1,2,3]
Since Blau Syndrome is so rare, there is limited information available for this condition. Thus, there is very limited data on the treatment approaches for this condition. However, from whatever data that is available, corticosteroids has been found to be very effective in treatment of Blau Syndrome. In cases where this is found to be ineffective, it is followed by other treatment regimens with immunosuppressive medications.[1,2,3]
What Causes Blau Syndrome?
As stated, Blau Syndrome is an autosomal dominant genetic disorder. This means that only one copy of the defective gene, which is the NOD2 gene in this case, is good enough for the child to inherit this condition from the parents. The immune system works by sending in white blood cells whenever there is presence of an invader like bacteria or virus is detected. When these white blood cells try to destroy the invader inflammation occurs.[2,3]
In cases of Blau Syndrome, due to the defective NOD2 gene, there is production of overactive proteins in the immune cells that result in abnormal inflammatory reactions. As of now, the scientists are not clear as to how the overactive protein produced by the defective NOD2 gene result in the kind of inflammation as seen with Blau Syndrome.[2,3]
In most cases, Blau Syndrome is inherited but there are some cases in which a person has Blau Syndrome without any family history of it usually because of abnormal genetic mutation.[2,3]
What are the Symptoms of Blau Syndrome?
The symptoms of Blau Syndrome are variable and tend to differ from individual to individual. The onset of symptoms of Blau Syndrome can be seen as early as 1 year of age. The first symptom that can be seen is a type of skin inflammation that produces continuous rashes generally on the upper and lower extremities and the chest. This medically is termed as granulomatous dermatitis. The rash may be scaly and may even form bumps under the skin surface.
A study has mentioned that the first symptom of Blau Syndrome of granulomatous dermatitis appear at around 1 year of age. This is then followed by problems with various joints of the body by the age 2. Ophthalmic involvement is seen by the time the child is 4 years of age. Some of the medical conditions that are commonly seen with Blau Syndrome are arthritis, tendonitis, fluid buildup around the joints, uveitis, conjunctivitis, kidney disease, and inflammation of the blood vessels. Rarely, Blau Syndrome can also cause inflammation of the vital organs of the body like the heart and brain which can have serious implications.
The Genetic and Rare Disease Information Center mentions that almost all the patients with Blau Syndrome have pain in the joints, inflammation of the corneas, skin discoloration at the site of the rashes, impaired mobility of the joint. It also mentions that approximately 80% of people have cataracts, severe photophobia, permanent bending of toes and fingers. Approximately, 30% of people with Blau Syndrome complain of vision loss, hypertension, difficulty breathing, lymph node swelling, open skin sores, and dry mouth.[2,3]
How is Blau Syndrome Treated?
Since Blau Syndrome is a genetic autoimmune disorder, there is no cure for it. However, there are treatments available to manage the symptoms of this condition. A study was done in 2015 of this disease that mentions effective use of corticosteroids in managing the symptoms as these medications calms down the inflammation during flare-ups.
Additionally, immunosuppressants are also quite effective in managing the symptoms of Blau Syndrome. TNF-alpha medications when given with corticosteroids and immunosuppressants in combination have also been found to be very beneficial in managing the symptoms of this condition.
What Is The Overall Prognosis Of Blau Syndrome?
The prognosis and outlook for a person with Blau Syndrome depends on the severity of the disease and the response of the patient to treatment. In most cases, the severity of the condition increases as the disease progresses. A study in which 31 children with Blau Syndrome who were being treated were analyzed showed that around 40% of the children had no effect on their function after treatment while around 30% showed mild impairment. However, 17% had moderate and around 10% had severe impairment due to the symptoms of Blau Syndrome.
In the same study, with regard to the quality of life, around 50% of the participants mentioned that they had moderate to severe problems with their quality of life and around 25% stated that Blau Syndrome did not impact their lives significantly.
In conclusion, Blau Syndrome is an extremely rare genetic auto-inflammatory disorder that is autosomal dominant and is caused by defect in the NOD2 gene. The function of this gene is to produce proteins that are important for the immune system of the body. As a result of this defective gene, people with Blau Syndrome tend to have an overactive inflammatory response.[1,2,3]
The onset of symptoms may be observed when the child is 1 year of age but the symptoms peak by the time the child is about 4 years of age. The symptoms of Blau Syndrome vary from person to person and tend to progress with age.[1,2,3]
The ophthalmic manifestation of Blau Syndrome is the primary symptom that is seen with inflammation of the uvea and corneas. There is no cure for this condition but corticosteroids and immunosuppressants have been found to be beneficial in managing the symptoms of Blau Syndrome.[1,2,3]