An infant born with familial dysautonomia typically has poor sucking ability, impaired swallowing reflexes, poor muscle tone (hypotonia), and/or abnormally low body temperature (hypothermia). Infants with this disorder may have cold hands and feet and experience unstable body temperature (from 94 to 108 degrees) during the course of infectious diseases. Profuse Sweating and drooling may also occur. Crying without tears is one of the most striking symptoms of familial dysautonomia. Sometimes a Lack of tears and insensitivity of the eyes to Pain from foreign objects (corneal anesthesia) can lead to Inflammation of the corneas and ulcerations in the eyes.
Children with familial dysautonomia have a decreased perception of Pain and lack of sensitivity to hot and/or cold temperatures; this can result in unnoticed injuries to the skin. Unstable blood pressure is usually present in infants with familial dysautonomia. Blood pressure readings may vary greatly and may be abnormally high or low.
Other symptoms of familial dysautonomia may include the absence of the sense of taste, impaired speech, and/or red blotches on the skin that appear with emotional excitement. Approximately 40 percent of children with this disorder experience episodes of vomiting. Occasionally there may be skeletal defects, absence of tendon reflexes, stunted height, and/or repeated episodes of pneumonia due to the inhalation of food (aspiration).
By adolescence, 95 percent of individuals with familial dysautonomia have evidence of side-to side spinal curvature (scoliosis). In addition, they may experience increased Sweating and an accelerated heart rate. A decreased awareness of Pain makes it difficult for children with this disorder to be aware of injuries; bone fractures may go unrecognized. Other symptoms that may appear during adolescence include weakness, leg cramps, and/or difficulty concentrating. Personality changes may also occur including depression, irritability, inability to sleep (insomnia), and/or negativism.
Approximately 20 percent of adults with familial dysautonomia over 20 years of age develop kidney insufficiency. Neurological deterioration also appears and unsteadiness in walking may become more apparent at this age.
A medical test is available that can determine if an infant has familial dysautonomia. Histamine is injected under the skin and response is measured along nerve cell fibers (axon flare). A lack of response confirms the diagnosis of familial dysautonomia.