walking, speech) may or may not be delayed.In infants with FD, a lack of overflow tears during emotional crying may be noted after the age of 7 months (until this age, overflow emotional tearing may also not occur in unaffected infants; overflow tearing is absent in neonates and begins to appear only after 2–3 months of age).Affected infants hands may alternatively appear cool and mottled (from vasoconstriction), or red and swollen (from vasodilation). Red skin blotching is often precipitated by emotional excitement.In older infants and young children, breath-holding spells may occur, possibly leading to cyanosis or fainting. Breath-holding behaviour usually ceases by age 6. Children
Breath-holding behaviour usually resolves by age 6. In school-age children, there may be bed wetting, vomiting episodes, impaired pain and temperature perception, impaired blood pressure control (including orthostatic hypotension, an hypertension during periods of psychological excitement or vomiting), learning disabilities (e.g. short attention span; learning disabilities are present in about a third of those with FD, and may require special education), scoliosis, poor bone quality and bone fractures, and kidney and heart issues. Adolescence and adulthood
Issues that tend to commence during adolescence or early adulthood include lung damage due to multiple respiratory infections, impaired kidney function, and impaired vision (due to atrophy of the optic nerve). By adulthood, there are often mounting difficulties with balance and unaided walking. Cause
Familial dysautonomia is the result of mutations in IKBKAP gene on chromosome 9, which encodes for the IKAP protein (IkB kinase complex-associated protein).
Familial dysautonomia (FD), also known as Riley-Day Syndrome, is a rare, progressive, recessive genetic disorder of the autonomic nervous system that affects the development and survival of sensory, sympathetic and some parasympathetic neurons in the autonomic and sensory nervous system. FD results in variable symptoms, including insensitivity to pain, inability to produce tears, poor growth and labile blood pressure (episodic hypertension and postural hypotension). People with FD have frequent vomiting crises, pneumonia, problems with speech and movement, difficulty swallowing, inappropriate perception of heat, pain and taste as well as unstable blood pressure and gastrointestinal dysmotility. Originally reported by Drs. Conrad Milton Riley and Richard Lawrence Day in 1949, 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.