What Is the Life Expectancy of a Person with Rett Syndrome?

Rett syndrome is a neurological disorder that affects girls only and is one of the most common causes of mental retardation in females.

Rett syndrome is a rare, genetic, degenerative neurodevelopmental disorder seen predominantly in females. The condition affects the way the brain develops and can lead to problems with movement, coordination, and language.

There are four stages of Rett syndrome, and each stage has different symptoms.

Stage I - Developmental arrest (6-18 months)

• Gross motor development delay
• Disinterest in play
• Loss of eye contact
• Low muscle tone 
• Hand wringing
• Unusual calmness
• Breath-holding spells 
• Slowing of head growth, weight gain, and height gains
• Other vague and nonspecific early symptoms

Stage II - Rapid deterioration or regression (1-4 years)

• Autistic-like behavior
• Stereotypic hand movements while awake – hand wringing, clapping, hand washing, or hand-to-mouth movements
• Breathing problems – hyperventilation or breath-holding
• Seizures and vacant spells that resemble seizures
• Sleep disorders
• Intermittent crossed eyes (strabismus)
• Irritability

Stage III - Pseudostationary (2-10 years)

• Some improvement in behavior, hand use, and communication skills
• Good eye contact and attempts to communicate intent
• Continued mental impairment and hand stereotypies
• Increasing rigidity, tooth grinding, hyperventilation, breath-holding, and involuntary tongue movements
• Motor dysfunction and seizures
• Continued breathing irregularities
• Deficient weight gain despite a good appetite
• Difficult feeding and some oral motor dysfunction
• Scoliosis

Stage IV - Late motor deterioration (over 10 years)

• No additional deterioration of cognitive skills, communication skills, or hand skills
• Increased motor problems
• Muscle contractions and rigidity, muscle wasting, weakness in all limbs
• Loss of ability to walk
• Possible reduction of seizure frequency
• Scoliosis or kyphoscoliosis
• Growth retardation
• Hyperventilation
• Improved frequency and intensity of hand movements
• Preserved eye contact

Rett syndrome is a rare genetic disorder caused by mutations in the MECP2 gene, which is located on the X chromosome. Women have two X chromosomes (XX), and men have one (XY).

Rett syndrome is due to a genetic mutation in a sperm cell or egg cell (de novo mutation) rather than an inherited genetic defect. In most cases, the defect comes from the father, which may explain why more females develop the condition than males.

A physical examination can often reveal the characteristics of Rett syndrome. Some testing may need to be performed to confirm the diagnosis. 

Laboratory tests may include:

• Genetic testing for patients who meet the diagnostic criteria for Rett syndrome
• Blood lactate, ammonia, pyruvate, and amino acids
• Urinary organic acids
• Chromosomal studies, including specific tests for Angelman syndrome (chromosome 15)
• Urinary tests for uroporphobilinogen to rule out intermittent porphyria (rarely helpful)

Other studies may include:

• Barium swallow study or overnight pH probe study
• Imaging studies such as magnetic resonance imaging (MRI)
• Electrocardiography (ECG)
• Electroencephalography (EEG)
• Neurophysiologic testing (auditory brainstem-evoked responses, somatosensory-evoked responses, electromyography [EMG])
• Electroretinography (ERG)
• Polygraphic respiratory recordings
• Psychometric testing

There are no medicines used to treat Rett syndrome but some symptoms may be managed with medications such as:

• Antiepileptic drugs (AEDs) for epilepsy
• Drugs for gastroesophageal reflux disease (GERD)
• Levocarnitine
• Sedative-hypnotics

Other therapies that may be used to treat Rett syndrome include:

• Vagal nerve stimulation
• Snoezelen multisensory approach, with or without hydrotherapy
• Gastrostomy tube
• Fundoplication, if GERD does not respond to medications
• Surgical treatment of scoliosis, if the condition does not respond to orthotics

A special diet may be indicated such as:

• High-calorie diet, with about 70% of calories from fats, 15% from carbohydrates and 15% from proteins
• Ketogenic diet (low carbohydrate, high fat)
• Supplementation for osteoporosis 
  • Vitamin D
  • Calcium 
  • Bisphosphonate 

Complications of Rett syndrome include:

• Problems eating which can lead to malnutrition
• Gastroesophageal reflux disease (GERD)
• Sleep problems 
• Seizures
• Scoliosis
• Need for lifelong care
• Shortened life expectancy 

Rett syndrome progresses through four stages, as follows:

• Stage I - Developmental arrest (6-18 months)
• Stage II - Rapid deterioration or regression (1-4 years)
• Stage III - Pseudostationary (2-10 years)
• Stage IV - Late motor deterioration (age over 10 years)

The average age of death for patients with Rett syndrome is about 24 years and in most cases, death is sudden and often secondary to pneumonia.

Risk factors for sudden death include:

• Seizures
• Loss of mobility
• Problems swallowing

With proper care including nutrition along with physical and occupational therapies, patients can often survive into their 40s or 50s, though with a severe disability.