Riley-Day syndrome Health Article

Definition

Riley-Day syndrome is an inherited disorder that affects the development and function of nerves throughout the body.

Alternative Names

Familial dysautonomia; Hereditary sensory and autonomic neuropathy - type III (HSAN III)

Causes, incidence, and risk factors

Riley-Day syndrome is passed down through families (inherited). A person must inherit a copy of the defective gene from each parent to develop the condition.

This condition is seen most often in people of Eastern European Jewish ancestry (Ashkenazi Jews), where the incidence is 1 in 3,700. The disease is caused by a change (mutation) of the IKBKAP gene on chromosome 9. It is rare in the general population.

Symptoms

• Breath holding spells (can lose consciousness)
• Constipation
• Decreased taste
• Diarrhea
• Dry eyes
• Feeding difficulties
• Inability to feel pain and changes in temperature (can lead to injuries)
• Long episodes of vomiting
• Poor coordination - unsteady walk
• Poor growth
• Repeated fevers
• Repeated pneumonia
• Seizures
• Skin blotching
• Sweating while eating
• Unusually smooth, pale tongue surface

Symptoms are present at birth and grow worse over time.

Signs and tests

The health care provider will perform a physical exam. The patient may have:

• Absent or decreased deep tendon reflexes
• Lack of a response after receiving a histamine injection (normally redness and swelling would occur)
• Lack of tears with emotional crying
• Low muscle tone (hypotonia), especially in babies
• Repeated episodes of high blood pressure
• Severe scoliosis
• Tiny pupils after receiving certain eye drops

Blood tests are available to check for the IKBKAP gene. The detection rate in the Ashkenazi Jewish population is greater than 99%.

Treatment

Treatment may include:

• Anticonvulsant therapy if there are seizures
• Feeding in an upright position and giving textured formula to prevent gastroesophageal reflux
• Increased fluid and salt intake, caffeine, and elastic stockings to prevent low blood pressure when standing (postural hypotension)
• Medicines called anti-emetics, to control vomiting
• Medicines, including liquid tears, to prevent dry eyes
• Physical therapy of the chest
• Protecting the person from injury
• Providing enough nutrition and fluids
• Surgery or spinal fusion
• Treating aspiration pneumonia

Expectations (prognosis)

With advances in diagnosis and treatment, survival continues to improve. Currently, a newborn with Riley-Day has a 50% chance of reaching age 30.