99.5% of cases of Rett Syndrome occur only once in a family.

Approximately 85% of all patients clinically diagnosed with Rett Syndrome (RTT) also test positive for a MECP2 mutation.

DIAGNOSTIC CRITERIA

Period of apparent normal development until 6 - 18 months
Normal head circumference at birth followed by slowing of the rate of head growth
Loss of verbal language and emerging social withdrawal
Purposeful hand use is replaced by stereotypical hand movements such as hand wringing/squeezing, clapping/tapping, mouthing
If able to walk the gait is usually wide-based and stiff legged
Shakiness of torso and/or limbs, especially when upset

SUPPORTIVE CRITERIA

Breathing pattern irregularities which include hyperventilation, breath holding, apnea, air swallowing
EEG abnormalities
Seizures
Scoliosis
Teeth grinding
Gastrointestinal issues which may include reflux, constipation, poor nutrient absorption
Growth retardation and decreased body fat and muscle mass
Biting/chewing/swallowing difficulties
Poor circulation to legs and feet
Decreased mobility with age
Muscle rigidity/spasticity/joint contractures
Small feet
Abnormal Sleep patterns
Irritability and agitation