Definition of Riley-Day syndrome:

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

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)
• Lack of tears when emotional crying
• 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 antiemetics, 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.

Complications:

The following complications occur in about 40% of patients with this condition:

• Blotching of the face and torso
• Excessive sweating of the head and torso
• High blood pressure (hypertension) and rapid heart rate (tachycardia)
• Insomnia
• Irritability
• Mottling of the hands and feet
• Nausea/vomiting
• Severe difficulty swallowing (dysphagia), drooling
• Worsening of muscle tone

Calling your health care provider:

Call your doctor if symptoms change or get worse. A genetic counselor can help clarify information about the condition and tell you how to contact support groups in your area.

Prevention:

People who are of an Eastern European Jewish background and families with a history of Riley-Day syndrome who are thinking of having children can seek genetic counseling to discuss their risk and undergo testing, when appropriate.

Genetic testing by DNA is very accurate for Riley-Day syndrome. It may be used for diagnosing affected individuals, detecting carriers, and prenatal diagnosis.