About Familial Dysautonomia

What is FD?

Familial dysautonomia (FD) is one example of a group of disorders known as hereditary sensory and autonomic neuropathies (HSAN).

All HSAN are characterized by widespread sensory dysfunction and variable autonomic dysfunction caused by incomplete development of sensory and autonomic neurons.

The disorders are believed to be genetically distinct from each other. Unlike the other HSAN, FD has been noted only in individuals of Ashkenazi Jewish extraction and so it is included as one of the Jewish genetic diseases.

Symptoms of FD

The most distinctive clinical feature is absence of overflow tears with emotional crying although it can be normal for a child not to have tearing until 7 months of age. Other signs of the disorder can be present from birth such as a high prevalence of breech presentation, weak or absent suck and poor tone.

Difficulty feeding is observed in 60% of infants in the neonatal period. Poor suck and misdirected swallows often persist and put the patient at risk for aspiration pneumonia, the major cause of lung infections. If gastroesophageal reflux is present, the risk for aspiration increases.

Approximately 40% of patients will react to stress (infection or emotional events) with a constellation of symptoms termed the dysautonomia crisis. In addition to vomiting, there is frequently increased heart rate and blood pressure, sweating, and a negative change in personality.

Further supportive evidence is provided by findings of decreased response to pain and temperature, wide swings in blood pressure, red blotching of the skin, and increased sweating. Other frequent signs are:

• delayed speech and walking
• unsteady gait
• corneal anesthesia
• breath-holding episodes
• poor growth
• spinal curvature (in 90% by age 13 yrs)
• red puffy hands