Familial dysautonomia is a certain type of hereditarydisorder which affects the autonomic nervous system. It also affects the properdevelopment of certain types of parasympathetic, sympathetic and sensoryneurons located in the sensory and autonomic nervous systems, and it all leadsto the development of a wide array of symptoms. This type of medical conditionis also sometimes referred to as the Riley-Day syndrome. Contrary to thepopular belief, this medical condition does not affect the intelligence of aperson. It was first reported in 1949 by Conrad Milton Riley and RichardLawrence Day and that is how it got its name. The modern medicine classifies thefamilial dysautonomia as a hereditary sensory dysfunction and variableautonomic HSAN. There are different types of HSAN, and all of them areassociated by incomplete development of autonomic and sensory neurons whichtrigger the variable autonomic dysfunction and sensory dysfunction.
FD is seen almostexclusively in Ashkenazi Jews
It is a very peculiar fact that the familial dysautonomia isalmost exclusively seen in Ashkenazi Jews (Jewish individuals of EasternEuropean ancestry). Since it is inherited in an autosomal recessive way, aperson may only inherit it if both parents carry the mutated genes. The carrierfrequency in Ashkenazi Jews is somewhere about 1 in 30, while the generalpublic is associated with a carrier frequency which is more like 1 in 3000. Incases where both parents carry the mutated gene, there is a 25 percent chancethat their child will inherit the familial dysautonomia. This is why allfamilies who suspect that they carry the mutated genes need to indulge inextensive genetic testing and genetic counseling in order to avoid the passingof the disease onto their children. Since the disorder was first discovered,there have been about 600 documented cases of the familial dysautonomia. Out ofall those people, there are approximately 350 of them who are still alive.
In order to be diagnosed with the familial dysautonomia, aperson needs to support a certain amount of criteria. The most common factorswhich need to be included are the lack of tears with emotional crying, lack ofan axon flare following an intradermal injection of histamine, decreased deeptendon reflexes, the absence of fungiform papillae on the tongue and anAshkenazi Jewish background. Some cases may also require genetic tests to beperformed. These tests require small samples of blood, so that the DNA can betested. Prenatal testing may also be required in some parents.
Symptoms in a baby and in an older child
The familial dysautonomia is present at birth and it isassociated with a large number of different types of symptoms. Babies and olderchildren usually do not experience the same types of symptoms. The symptomscommonly displayed in babies may or may not include persistent bilateral eyeirritation, red blotching of the skin, misdirected swallowing, poor suck, poortone, absent suck, weak suck, high prevalence of breech presentation, and anabsence of overflow tears with emotional crying after 7 months of age. Older childrencommonly experience different symptoms of the familial dysautonomia, such asred puffy hands, unstable blood pressure, erratic blood pressure, poor growth,less perception in temperature changes, less perception in painful sensations,corneal abrasion, spinal curvature, unsteady gait, delayed walking and delayedspeech. Some cases may also involve the condition called dysautonomia crisiswhich commonly included various symptoms as a response to emotional or physicalstress. This constellation of symptoms may also be accompanied by a negativechange in the personality, blotching of the skin, drooling, excessive sweating,increase in blood pressure, increased heart rate and vomiting.
Treatment of Manifestations
Even though the exact gene responsible for the onset of thefamilial dysautonomia has been identified, there are still no specifictreatment options available which would guarantee the complete healing. The currenttreatment options are characterized by a supportive, symptomatic andpreventative nature. The type and severity of symptoms may vary constantly,because this medical condition does not get expressed in a consistent orcontinuous manner. This is why each individual case of familial dysautonomiarequires special treatment plans, carefully tailored to the specific needs ofthat patient. Compensating for labile blood pressures is sometimes used. Thespinal curvature and tibial torsion are commonly treated as orthopedic types ofproblems. The orthostatic hypotension is usually dealt with by utilizing a highsalt diet, frequent small meals, leg exercises, proper hydration andmedicaments such as fludrocortisones. The child needs to be well protected fromdifferent types of injuries. The daily chest physiotherapy may be helpful insome cases, as it involves the utilization of postural drainage,bronchodilators and nebulization. The child always needs to be supplied withproper amounts of all nutrients. In cases of excessive eye dryness, artificialtears are commonly used.