This is a rare disorder of the autonomic nervous system that controls the involuntary body functions of the individual. Dysautonomia familial is apparent at the birth of the infant that is characterized by insensitivity to pain, inability to produce tears, problems in regulating the body temperature and unstable blood pressure. This rare genetic disorder appears to primarily affect the infants of the Ashkenazi Jewish or the Eastern European ancestry with an estimation of 1 in 30 of the East European Jewish ancestry population to be the carrier of this disorder. The average age of these affected individuals is around 15 years but the statistics show that they have a 50% chance of survival into 40 years of age. In most cases, death occurs as the result of pulmonary complications.
Causes
The genetic mutation identified to cause this condition is IKBKAP which is necessary to produce a protein known as IKK compound-associated protein (IKAP) that is usually present throughout the body. The mutation in this gene can impair the production of IKAP protein resulting in its insufficiency. The essential brain activities may be affected because of reduced or absence of IKAP protein resulting in the symptoms of this disorder. The inheritance pattern is autosomal recessive trait meaning both the copy of the gene in each cell are defective. The parents of the affected individual may each be the carrier of the defective gene but don’t necessarily present any symptoms associated with this condition.
Symptoms
This progressive disease varies in severity between each of the affected cases. Some of the symptoms of dysautonomia, familial include feeding difficulties, corneal drying, poor muscle tone, excessive sweating, poor weight gain, smooth tongue and lack of taste buds, spinal curvature, short stature, delayed developmental milestones, inappropriate temperature controls, a variation of blood pressure and sleep apnea. Additional abnormalities can include osteoporosis and osteopenia, restrictive lung disease, episodic vomiting, gastro-esophageal reflux and frequent infections.
Diagnosis
The diagnosis is based on the clinical evaluation and in the identification of features that are characteristic of this condition. This can include the examination that seeks to identify lack of tears with crying, tiny pupils after delivering certain eye drops, decreased deep tendon reflexes and episodes of high blood pressure. The carrier testing is also available for the two common types of mutation among the Ashkenazi Jewish population.
Treatment
There is no cure for this disorder and the treatment usually provides supportive care. Various medications can relieve the symptoms of dysautonomia, familial and the artificial tears can lubricate the eyes. The supportive therapies can consist of medications to regulate cardiovascular, respiratory and gastrointestinal function. Additionally, they may require physical therapy, occupational therapy, feeding facilitation and speech therapy. Genetic counseling may be beneficial for the family of the affected child.
References
https://rarediseases.org/rare-diseases/dysautonomia-familial/
http://www.familialdysautonomia.org/facts.htm
https://ghr.nlm.nih.gov/condition/familial-dysautonomia#genes
http://www.jewishgeneticdiseases.org/diseases/familial-dysautonomia/
