About this condition
Familial Dysautonomia
Familial dysautonomia (FD, Riley-Day syndrome, hereditary sensory and autonomic neuropathy type III) is an autosomal recessive neurodevelopmental disorder caused by pathogenic variants in ELP1 (elongator complex protein 1, formerly IKBKAP) on chromosome 9q31.3. ELP1 is a component of the Elongator complex involved in tRNA modification. Deficiency leads to progressive degeneration of sensory and autonomic neurons. The condition is almost exclusive to the Ashkenazi Jewish population, where a single founder splice site variant (c.2204+6T>C in intron 20) accounts for over 99% of disease alleles. Carrier frequency is approximately 1 in 30-36 Ashkenazi Jews.
FD presents in infancy with feeding difficulties, absent overflow tears (alacrima — virtually pathognomonic), absent fungiform papillae on the tongue, and reduced response to pain and temperature. Autonomic dysfunction produces episodic hypertensive crises (dysautonomic crises) with nausea, vomiting, tachycardia, and hypertension — triggered by emotional stress, illness, or anesthesia. Cardiovascular instability is the leading cause of sudden death. Progressive sensory neuropathy leads to corneal ulceration (from absent protective tearing), orthopedic complications from insensitivity to injury, and progressive gait ataxia.
Survival has improved dramatically with modern management — median life expectancy now exceeds 40 years with optimal care, compared with childhood mortality in the pre-treatment era. Management includes artificial tears and corneal protection, antihypertensive therapy during dysautonomic crises, careful anesthesia protocols (specialized centers only), scoliosis management, and proactive pulmonary care (aspiration pneumonia is a major morbidity). There is no disease-modifying therapy, making carrier screening and reproductive planning the primary prevention strategy.
Anesthesia in FD patients requires specialized protocols — autonomic instability during surgery can cause life-threatening hypertensive or hypotensive crises. Only anesthesiologists experienced with FD should manage these patients.
- Gene locus
- ELP1 (9q31.3)
