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).
Papular xanthoma is a cutaneous condition that is a rare form of non-X histiocytosis. : 718

See also
Non-X histiocytosis
List of cutaneous conditions


== References ==