Rett syndrome affects females nearly exclusively, and is a progressive neurological disorder. Progressive neurological disorders are ones which get worse as time passes, and the outcomes of Rett syndrome symptoms are developmental regression and mental retardation. In the case of Rett syndrome, infants appear to be engaging in normal development, reaching milestones such as self-feeding, smiling and reaching, up until the age of approximately three to five months.
Symptoms: Stage One
The symptoms of Rett syndrome can be described in four stages. In the first stage, the growth of the infant's head begins to slow. This is called acquired microcephaly. This continues on from the age of three to five months, until the child is several years old. Following from this, additional symptoms or abnormalities develop which may not initially be recognized as such. Affected infants may reach other developmental milestones, such as crawling, sitting and standing, at a later rate, or cease entirely to learn any new skills. Other early symptoms of Rett syndrome include inattention, lack of eye contact and hypotonia, or diminished muscle tone.
Symptoms: Stage Two
The second stage of Rett syndrome symptoms is called the Regressive Stage. Between the ages of one and four years, children with Rett syndrome experience a loss of previously understood and grasped skills that happens either suddenly, gradually or in increments. This includes the loss of previously acquired language and purposeful use of the hands. Children experience uncontrolled hand and finger movements that occur incessantly while they are awake. The child may also engage in involuntary teeth clenching, grinding and chewing. Additional symptoms which are common to the Regressive Stage of Rett syndrome are apraxia, which is the loss of the ability to coordinate purposeful movement, balance disturbances, gait apraxia, which is the inability to perform the motor actions necessary for walking, fine tremors in the limbs and torso and respiratory problems. Alongside these neurodevelopmental regressions are physical symptoms. Children with Rett syndrome also experience delays in growth, digestive tract abnormalities, decreased bone density and constipation.
Symptoms: Stage Three
The third stage of Rett syndrome is from early to mid-childhood, from several years old until approximately ten years old. Here, symptoms stabilize as the developmental regression finally ceases. However, this stage brings with it several new symptom possibilities. The affected individual can develop greater motor difficulties, seizures, and scoliosis that at times becomes somewhat severe in later years. Positive results of this stage include the possibility of slight developmental gains, such as a greater interest in the environment and better communication. Many individuals with Rett syndrome remain in the third stage of symptoms.
Symptoms: Stage Four
Late motor impairment is key Rett syndrome symptoms. This occurs in the fourth stage of the disorder. After ten years old, it is possible for children who previously gained the skill of walking to slowly lose it. Additional symptoms encountered in the fourth stage are dystonia, or muscle contractions that result in distorted and twisted muscle posturing, spasticity, muscle weakness, myoclonus, or jerky, rapid movements, and worsening scoliosis. Possible symptom improvements include lessening seizures, improved breathing, lessening hand movements and increased attention span.
Rett Syndrome Fact Sheet: National Institute of Neurological Disorders and Stroke https://www.ninds.nih.gov/disorders/rett/detail_rett.htm
We Move: Rett Syndrome https://www.wemove.org/rett/rett_sym.html
Penn State Children`s Hospital: Rett Syndrome https://www.hmc.psu.edu/childrens/healthinfo/r/rhett.htm