What is Familial Dysautonomia (FD)?

Familial dysautonomia (FD) is an inherited disorder that affects the nervous system. It is one of many hereditary sensory and autonomic neuropathies (HSAN). Patients with FD have a decreased sensitivity to pain, inability to produce tears, poor growth, syncope, as well as a myriad of other complications. While the disease is quite serious and was often fatal in the past, medical advances have improved the likelihood of survival.

Who gets FD?

In order for a child to get the disease, both parents must be carriers. If both parents are carriers, they have a one in four chance of their child having the disease. The disease is seen almost exclusively in Ashkenazi (those of Eastern European ancestry) Jews. This is mainly because there is a significantly higher carrier frequency among the Ashkenazi Jew population. FD has an incidence of one in 3600 live births among Ashkenazi Jews.

What causes FD?

Familial dysautonomia is caused by a decreased amount of functional IKAP protein in cells. This is always the result of one of three genetic mutations in IKBKAP gene on chromosome 9. This is what encodes for IKAP protein. As a result of the genetic mutation, the body has a decreased amount of functional IKAP protein. Thus, causing FD.

What are the symptoms of FD?

Symptoms of FD can vary from person to person. They are usually present shortly after birth, but can sometimes take awhile longer to appear. The disease generally tends to get worse with time. Infants with FD usually have feeding difficulties with uncoordinated swallowing and risk of aspiration pneumonia. Older infants have an absence of tears, usually evident after seven months. Older children have slow growth, delayed speech and walking, problems with their blood pressure, and decreased sensitivity to pain. FD patients suffer from dysautomatic crises in response to stress. During these episodes, patients experience vomiting, tachycardia, hypertension, sweating, drooling, and a change in personality.

How is FD diagnosed?

If a patient is thought to have the disease, the doctor will first look at the symptoms. More specifically, the doctor will look for distinctive clues such as absence of tears or decreased deep tendon reflexes. Often times, the doctor will administer a histamine test. In a normal individual, histamine will cause an inflammatory response. However, in patients of FD, no response occurs. The only true test for FD is genetic testing. The test is highly accurate.

How is FD treated?

There is no cure for FD. There is also not a treatment for the disease itself. Instead, treatment is aimed at either alleviating or preventing the many complications of the disease. The type and severity of symptoms vary from person to person and can even vary within an individual during different times in his/her life. Therefore, patients have specialized individual treatment plans that often change.

What is the prognosis of those with FD?

Due to medical advances, survival rates have greatly increased. In the past, only fifty percent of patients were expected to live past their fifth birthday. However, current survival statistics indicate that a newborn with FD has a fifty percent probability of reaching the age of forty. As long as the disease is found early on and treatment is started as soon as possible thereafter, patients can expect to live a relatively normal life.