FD Fact Sheet
In individuals with FD, a progressive
neurogenetic disorder, the autonomic and sensory nervous systems
malfunction. Symptoms vary, and may include insensitivity to
pain, unstable blood pressure and body temperature, absence of
overflow tears, frequent pneumonia, and poor growth. FD is often
associated with a shortened lifespan. Individuals with FD suffer
from episodes of cyclical vomiting accompanied by extremely high
blood pressure and increased heart rate, sweating and fever.
These “autonomic crises” are one of the most devastating
symptoms of this disease, often requiring hospitalization.
disease: familial dysautonomia
(FD), also known as Riley-Day Syndrome
Carrier frequency in Ashkenazi Jews: 1 in 27
Carrier frequency in the general population: unknown
Age of onset: birth
FD causes dysfunction of the autonomic and sensory nervous
systems. It is a progressive disease. Symptoms and severity vary
in each patient. Symptoms include:
Absence of overflow
tears / corneal drying
Poor suck at birth
Swallowing & feeding
Hypotonia / poor
milestones: motor, language, social
Wide swings in blood
infections or pneumonias
Decreased or no
reaction to pain and temperature
Blotchy reddening of skin with excitement and/or
Smooth tongue / lack of taste buds
Poor weight gain and growth
Impaired renal function
Osteoporosis and osteopenia
Fainting and cardiac arrhythmias
Restrictive lung disease
lifespan: Currently, the mean
age of the FD population is approximately 15 years. By
statistical projection, babies born with FD in 2006 have a 50%
chance of surviving to 40 years of age. The major causes of
death are the result of pulmonary complications or sudden death
due to autonomic instability.
the basis of disease:
Inefficient gene splicing results in decreased production of a
vital protein called IKAP. This protein is an essential
component of a complex that aids in expression of multiple other
target genes that are critical for growth and development of the
sensory and autonomic nervous systems as well as their function.
There is no cure for FD.
Treatments are supportive and preventative. Supportive therapies
include medications to maintain and regulate cardiovascular,
respiratory, and gastrointestinal function. Surgical
interventions include fundoplication, gastrostomy, spinal
fusion, and tear duct cautery.
Various therapies are used to
promote strength and speech development.
testing: Carrier testing is
available for the two most common mutations. All patients have
one or two copies of a single splicing mutation; over 99% of
cases of FD in the Ashkenazi Jewish (AJ) population have two
copies of this splicing mutation. A second mutation paired with
the AJ splicing mutation accounts for all other cases in the AJ
population. A third mutation from a non-Jewish parent, again
paired with the AJ splicing mutation, is responsible for a
single case of FD.
testing information: Carrier
screening is based on DNA analysis. Screening is 99% accurate
for the AJ population.
research: Research focuses on
modifying the splicing defect in order to increase production of
IKAP as well as to further understand the role of this vital
protein. Researchers are also constructing an FD mouse
model to further this aim. Clinical investigations include
assessment of sleep physiology and assessment of molecular and