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Click on a question from the list below to see the answer.
What is Rett syndrome?
What causes Rett syndrome?
My child has Rett syndrome. How will this affect our daily life?
Development seemed so normal. What happened?
What does my child’s mutation mean?
Does my child’s mutation type determine her clinical features or symptoms (phenotype)?
If it is genetic, does this mean I may have another child with RTT?
Should family members be tested?
What kind of handicaps will she have?
Since skills are lost, is RTT degenerative?
How often does RTT occur?
What disorders must be ruled out?
How does RTT differ from autism?
How is the RTT diagnosis made?
How can I be sure my daughter has it?
Is Rett syndrome seen predominantly in one race?
What are the stages of Rett syndrome?
Do all girls move through the stages of Rett syndrome similarly?
What will she be able to do?
What drugs have been tried?
What is life expectancy?
What are the causes of death?
When she dies, what can we do to help find answers?
What has research taught us about RTT?
What has research found?
How do we know that RTT is a condition of developmental arrest?
What are some other research findings in RTT?
What happens when she hyperventilates?
What happens when she holds her breath?
Are the abnormal breathing episodes or tremors related to seizures?
What should we do about her irregular breathing?
How can breathing be so abnormal when she is awake and normal when she sleeps?
Are the breathing problems dangerous to her health?
How can I tell if she is swallowing air?
Should she have an electrocardiogram (ECG)?
What can be done about heart irregularities?
Where do I go for more information?
What is Rett syndrome?
Rett Syndrome (RTT) is a unique neurodevelopmental disorder which
begins to show its affects in infancy or early childhood. It is seen
almost exclusively in females, although it can occur rarely in boys. It
is found in all racial and ethnic groups throughout the world.
What causes Rett syndrome?
Rett syndrome is primarily caused by a sporadic mutation in the MECP2
gene on the X chromosome. The MECP2 gene makes a protein, also called
MeCP2, believed to play a pivotal role in silencing, turning off or
regulating the activity of other genes. The MECP2 mutation (change in
the gene) causes the turn-off/regulatory mechanism to fail, allowing
other genes to function abnormally. So, RTT is a genetic disorder of
developmental arrest or failure of brain maturation. This is thought to
occur when subsets of neurons and their connections (synapses) are
disrupted during a very dynamic phase of brain development. This
deviation occurs at the end of pregnancy or in the first few months of
life during the critical phases of synapse development. How mutations
in MeCP2 lead to RTT is not well understood but is the focus of intense
research.
My child has Rett syndrome. How will this affect our daily life?
The age when RTT begins and the severity of different symptoms may
vary. The child with RTT is usually born healthy and shows an early
period of apparently normal or near normal development until 6-18
months of life, when there is a slowing down or stagnation of skills. A
period of regression then follows when she loses communication skills
and purposeful use of her hands and slowing of the normal rate of head
growth become apparent. Soon, stereotyped hand movements and gait
disturbances are noted. Other problems may include disorganized
breathing patterns which occur when she is awake and seizures. There
may be a period of isolation or withdrawal when she is irritable and
cries inconsolably. Over time, motor problems may increase, while
interaction and communication, especially with eye gaze, seizures, and
irregular breathing may improve. Most individuals with RTT require
maximum assistance with every aspect of daily living.
The very basics of caregiving include what we do every day: feed,
bathe, clothe, toilet and possibly give medication. We may have to lift
and carry her, or help her walk, reposition her often for comfort, or
change a bib for drool. We might have to program and reprogram a
communication device. We most definitely must know how to operate and
keep a DVD or MP3 player charged at all times. We have to learn how to
find the right professionals, schedule appointments and therapies,
search for the right schools or programs, and provide special
equipment.
We need to take a really hard look at how we’re doing things and how it
affects us and the rest of our family. While we can’t erase RTT today,
we can face it. It is important to do all that we can, but at the same
time recognize that we can’t do it all. We can learn from the
information offered by the IRSF, collected over the years from
thousands of parents, caregivers, and professionals, so we can make
important changes that will make a positive difference in our daily
lives.
Development seemed so normal. What happened?
RTT results from a chain of events beginning with the MECP2 genetic
mutation. Mutations occur naturally in everyone all the time and most
do not cause problems. The MECP2 mutation results in a shortage or
absence of normal MeCP2 protein needed to regulate or direct other
genes. These other genes affect or control the normal development of
selected regions of the brain responsible for sensory, emotional, motor
and autonomic function during the critical period of infancy when
important milestones are expected to be achieved. Development appears
to be normal in early infancy until the MeCP2-related regulation or
control is needed. Without these controllers, selected regions of the
brain do not develop properly. This explains why the child appears to
be developing normally in the first months of life.
What does my child’s mutation mean?
The discovery of the MECP2 gene made possible the development of a
blood test for RTT. The diagnosis of the disorder, however, is still
based on symptoms and clinical history.
At this time, approximately 85% of all patients diagnosed with RTT also
test positive for a MECP2 mutation. This does not mean that the
remaining 15% do not have RTT. Although testing positive for a mutation
confirms the diagnosis it is not required. It is possible that
mutations exist in an area of MECP2 that has not yet been sequenced, or
perhaps other genes contribute to RTT.
Until 2004, the majority of mutations in MECP2 were identified by
analyzing the DNA sequence. At that time, 80-85% of girls fulfilling
the consensus criteria for RTT had a mutation in this gene. Picture the
MECP2 gene as a book with 4 chapters. Mutations may include having a
missing page(s), an extra page(s) or pages in the wrong order. In some
cases an entire chapter or two chapters may be missing. The correct
term for the chapters is exons. Most mutations were found in exons 3
and 4 (MECP2 has 4 exons, but exon 1 was thought to be silent). More
than 200 different mutations in MECP2 that cause RTT have been
identified. Yet, eight specific mutations are the most common and
account for more than half of all individuals with RTT.
Since 2004 a small number of mutations have been identified in exon 1.
Even more importantly, the presence of large deletions was detected.
These large deletions consisted of loss of an entire exon or more. The
large deletions are detected by a completely different method.
Combining this new information, 95% or more of girls fulfilling
consensus criteria have mutations in MECP2. In addition, we are now
beginning to identify MECP2 mutations in males, some of whom have
features of RTT, others lacking these features, but instead having much
more severe problems leading to early death.
If a child has tested negative for MECP2 mutations in the past please consider these additional tests.
Mutations in another gene on the X-chromosome known as CDKL5
(cyclin-dependent kinase-like 5) can cause an atypical form of Rett
Syndrome called the early-onset seizure variant. These individuals have
generally tested negative for a MECP2 mutation. Not everyone with a
CDKL5 mutation appears as atypical RTT. Other CDKL5 disorders include
Infantile Spasms, West Syndrome, Early Onset Seizures, and Autism.
CDKL5 mutation testing is not routinely available through most
diagnostic labs. If you think your child should have this testing, you
should discuss it further with your pediatrician, neurologist, or
geneticist. For more information visit http://www.cdkl5.com
Does my child’s mutation type determine her clinical features or symptoms (phenotype)?
Just as in any other disorder, the level of disability ranges from mild
to severe. It is difficult to predict the intensity of symptoms in any
individual child. Many girls begin walking within the normal range,
while others show significant delay or inability to walk independently.
Some begin walking and lose this skill, while others continue to walk
throughout life. Still others do not walk until late childhood or
adolescence. The same range holds true for using her hands and other
skills she may acquire.
The clinical features of a particular trait or disorder make up an
individual’s phenotype. The gene for a given trait or disorder leads to
the person’s genotype. By comparing the two, we are able to correlate
the clinical features with a given mutation. In Rett syndrome, this may
allow us in the future to make certain predictions on the likelihood of
developing specific features such as scoliosis or epilepsy, but much
data must still be collected before we can make these predictions.
One way to grow this the body of knowledge is to contribute to
InterRett - the IRSF Rett Phenotype Database
www.ichr.uwa.edu.au/rett/IRSF
This project collects information about the features of Rett syndrome
from parents and clinicians. These details are then collated to form an
online searchable database. To participate email
This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
You will be sent details about entering your information online.
If it is genetic, does this mean I may have another child with RTT?
The chance of having more than one child with RTT is very small, much
less than one percent. This means that more than 99.5% of the time, the
mutation is sporadic, occurs only with this conception and is not
repeated in a family. Overall, the bottom line on recurrence risks: If
you have an affected daughter and no other affected relatives, the
recurrence risk is much less than 1% for your family (you and your
children). In families with more than one affected child, the situation
is different and would need to be addressed individually through a
skilled genetic counselor.
Should family members be tested?
Both parents can be tested for germline mutations before deciding to
have other children. If a mother has a germline mutation, then her
daughters who seem to be unaffected may wish to be tested when they
reach reproductive age as they too may be asymptomatic or silent
carriers. Finally, prenatal testing of any babies conceived in a family
where RTT has already occurred is also an option. These options all
need to be explored individually through a skilled genetic counselor.
What kind of handicaps will she have?
Apraxia (dyspraxia), the inability (or reduced ability) to program the
body to perform motor movements, is the most fundamental and severely
handicapping aspect of RTT. It can interfere with every body movement,
including eye gaze and speech, making it difficult for the girl with
RTT to do what she wants to do. Due to this apraxia and her inability
to speak, it is very difficult to make an accurate assessment of her
intelligence. Most traditional testing methods require her to use her
hands and/or speech, which may be impossible for the girl with RTT. Her
mobility may be delayed and she may have difficulty crawling or
walking.
Since skills are lost, is RTT degenerative?
Rett syndrome is not a degenerative disorder, but rather is a
neurodevelopmental disorder. Barring illness or complications, survival
into adulthood is expected.
How often does RTT occur?
The worldwide prevalence rate ranges from 1:10,000 to 1:23,000 live
female births, making it two to three times more common in females than
phenylketonuria (PKU), a congenital error of metabolism for which every
newborn in the USA is tested. RTT is most often misdiagnosed as autism,
cerebral palsy or non-specific developmental delay. While many health
professionals may not be familiar with RTT, it is a relatively frequent
cause of delayed development in girls.
What disorders must be ruled out?
Other possible conditions which could look like RTT must be ruled out.
They include Angelman syndrome and the infantile form of neuronal
ceroid lipofuscinosis. Females with RTT are often misdiagnosed as
autism and cerebral palsy. Careful clinical assessment can
differentiate these disorders.
How does RTT differ from autism?
The MECP2 gene mutation is most often found in RTT. Some females with
such mutations may exhibit features more typically seen in autism.
While RTT occurs primarily in girls, autism occurs much more frequently
in boys. In both conditions, speech and emotional contact are impaired.
However, females meeting criteria for RTT do not meet those for autism
and symptoms seen in RTT and not in autism include deceleration of the
rate of head growth, loss of purposeful hand skills, and mobility or
the irregular breathing patterns. While hand flapping is seen
frequently in autism, the repertoire of purposeless hand stereotypes
common to RTT are not seen in autism. The girl with RTT almost always
prefers people to objects, but the opposite is seen in autism. Unlike
those with autism, the RTT girl often enjoys affection. While girls
with RTT often have autistic-like features at an early age, these
features disappear.
How is the RTT diagnosis made?
In making this clinical diagnosis, specialists rely on a RTT Diagnostic
Criteria Worksheet, which has been developed by the world's foremost
authorities in RTT. Your child's doctor will look carefully at her
early growth and development and will evaluate her medical history and
physical and neurological status. Finding a MECP2 mutation is not
required. Your daughter may fall into one of three categories:
- Classic RTT: those who meet the consensus diagnostic criteria;
- Atypical
RTT: those who do not meet all of the diagnostic criteria for classical
RTT. The diagnosis of atypical RTT must include at least three of the
primary criteria and five of the eleven supportive criteria. Atypical
RTT accounts for 15-20 percent of all RTT diagnoses.
Types of atypical RTT include:
- Congenital
Onset RTT: developmental delay is noticed shortly after birth with no
early normal development; or severe seizures in early infancy impairing
early development.
- Late Onset RTT: signs are delayed beyond the typical 18 month onset, in some cases to age 10 years or more.
- Preserved Speech RTT: milder features are seen
- Male RTT: May be seen in males with Klinefelter (XXY) or somatic mosaicism
How can I be sure my daughter has it?
Most parents know their daughters better than anyone. Often, they know
that Rett syndrome fits from the first description. Physicians use
Diagnostic Criteria Guidelines
Is Rett syndrome seen predominantly in one race?
No. A statewide population study in Texas has revealed that the
incidence of RTT in the African-American and Hispanic population in the
United States is comparable to that in Caucasian Americans.
What are the stages of Rett syndrome?
- Stage I
Early Onset Stage
Age: 6 months to 1.5 years
Duration: Months
- Stage II
Rapid Destructive Stage
Age: 1 to 4 years
Duration: Weeks to Months
- Stage III
Plateau Stage
Age: Preschool to adulthood
Duration: Decades
- Stage IV
Late Motor Deterioration Stage
Age: When ambulation is lost (those who never ambulate move from Stage II to IV, 5-25+ years
Duration: Up to decades
Do all girls move through the stages of Rett syndrome similarly?
No. The stages of Rett syndrome are guidelines provided to help
understand the natural history of the disorder. The course of RTT is
predetermined according to her mutation and X-inactivation status, and
varies from one child to another, including the age when RTT begins and
the speed and severity of symptoms. Therefore, two girls of the same
age can appear quite different.
What will she be able to do?
Although the girl with RTT will need help for most activities of daily
living, she can learn some independent skills. Girls can learn to use
the toilet with assistance and may learn to feed themselves by hand or
with utensils with some assistance. Some girls can learn to use
augmentative devices to communicate. Despite their difficulties, girls
and women with RTT can continue to learn and enjoy family and friends
well into middle age and beyond. They express a full range of emotions
and show their engaging personalities as they take part in social,
educational and recreational activities at home and in the community.
What drugs have been tried?
- L-Dopa is a synthetic form of dopamine. It has been
found to improve rigidity during the motor deterioration stage (4), but
otherwise failed to provide improvement on a consistent basis.
- Naltrexone (Revia)
is an opiate antagonist, used to alleviate the drug high in addicts. It
was tried in RTT due to the unusually high level of naturally-occurring
opium-like brain chemicals called endorphins in the spinal fluid of
girls with RTT, and their diminished response to pain. The study was
limited to the dose of 1 mg/kg/day and did not show dramatic results.
However, independent studies have shown that use of naltrexone in
higher or lower doses may be beneficial in controlling irregular
breathing and seizures, and in alleviating screaming spells. This may
be due to the drug's sedative effects. One negative aspect of the study
was that performance on the Bayley Scales of Infant Development was
significantly worse during the administration of the drug compared to
placebo, also possibly due to its sedative effect. Another negative
side effect is loss of appetite.
- Bromocriptine (Parlodel)
is a drug which improves the functioning of the dopamine system in the
brain. One drug trial showed initial improvements in communication,
decreased agitation and reduced hand movements in the first phase;
however, when the drug was stopped symptoms reappeared, and the
reintroduction of the drug did not bring back the initial improvements.
The drug was found to be most effective in those girls who had milder
symptoms.
- Tyrosine (dopamine and noradrenalin) and tryptophan (serotonin)
are amino acids, used to boost neurotransmitter levels. The study
indicated no differences in clinical performance or EEG patterns.
- L-Carnitine
is a derivative of the essential amino acid lysine, and is often found
to be deficient in those who take anticonvulsants. A single case report
of one child indicated improvements in language and awareness. However,
the child reported was an atypical case of RTT, and these results have
not been replicated. In another study of 35 girls, carnitine
supplements (100 mg/kg/day) did not lead to any major neurological
improvements in the group as a whole. However, approximately 75% of the
families involved in the study reported subtle, but important
improvements to their quality of life while on the drug, including
increased alertness, increased mobility, less daytime sleeping,
increased energy, and improvement in constipation. Some parents
reported their daughter saying a word for the first time in a number of
years. L-carnitine has been found beneficial in a large group of girls
with RTT to increase muscle mass. A beneficial side effect is loose
stools.
The Blue Bird Circle Rett Center at Baylor College of Medicine,
Houston, Texas and the Rett Center for Excellence at the University of
Alabama at Birmingham conducted a double-blind placebo-controlled
treatment study using betaine and folate. No objective improvement was
noted, but parents did describe improved alertness and interaction in
those receiving the active agents.
A clinical drug trial using dextromethorphan (DM) has been initiated at
the Children's Center in Johns Hopkins Hospital. It has been shown that
receptors for the excitatory amino acids glutamate, in particular the
NMDA type, are increased in the brain of young girls with RTT. This
neurotransmitter and its receptors, when in excess, cause harmful
over-stimulation of the nerve cells (neurons) in the brain,
contributing in part to the seizures, behavioral phenotype, and
cognitive impairment, in RTT. The study will examine the effects of
this neurotransmitter and its excessive receptors using DM because of
its identified ability to block NMDA receptor channels. This drug is
approved for human use. Infants with respiratory infections and cough,
as well as non-ketotic hyperglycinemia have been treated with DM. It
has been well tolerated. The clinical trial will study the benefits of
DM vs. placebo on EEG, seizures, cognition, and motor impairment seen
in RTT.
What is life expectancy?
Due to the rarity of RTT, very little is known about long term
prognosis and life expectancy. Most of those who have been identified
are under 18 years of age. It is often difficult to identify older
girls and women due to the frequent lack of complete infant and
childhood developmental records. However, studies have determined that
a girl with RTT has a 95% chance of surviving to age 20-25 years. This
compares to a 98% survival probability for the general U.S. female
population. Between the ages of 25-40, the survival rate drops to 69%
in RTT, compared to 97% in the general U.S. female population. The
average life expectancy of a girl given the diagnosis of RTT may exceed
47 years. While a few women in their 40's and 50's are known to have
RTT, but too few women have been identified to make reliable estimates
beyond age 40. While these statistics show that life expectancy is less
in RTT, it is not nearly as low as previously thought or as other
similar neurological disorders.
What are the causes of death?
It is important to note that only ~5% of cases reported to the IRSF
have resulted in death. This means that 95% of those diagnosed are
still living. The most frequently reported causes of death (one-quarter
of deaths) are variations of sudden, unexplained death with no apparent
underlying cause such as an acute injury or infection. The factors most
strongly associated with an increased risk of sudden unexplained death
in RTT are uncontrolled seizures, swallowing difficulties and lack of
mobility. Physical, occupational therapy, nutritional status or living
arrangements made no difference in the incidence of sudden unexplained
death. Other deaths have resulted from pneumonia. The factors most
strongly associated with an increased risk of death by pneumonia are
compromised lung function due to scoliosis and difficulty swallowing.
Other causes of death include malnutrition, intestinal perforation or
twisted bowel, as well as accidents and illness.
When she dies, what can we do to help find answers?
Although she may be at higher risk for life-threatening events such as
pneumonia, choking and seizures, it is very likely that your daughter
will live a long life. However, we are all at risk for accidents of
many types and illnesses that are unexpected. A time will come when we
will all die. Researchers are ready to listen, to learn, and to share.
You can participate in research studies that will help us understand
RTT.
What has research taught us about RTT?
Studies have revealed that although the brain is 30% smaller than
normal, no obvious malformations, gross abnormalities or signs of
infection are present. Brain neurons are smaller than normal and have
reduced branching. The number of synapses (brain-cell to brain-cell
connections) is about half the normal number which interferes with
functions such as thinking, doing, and feeling. Abnormalities in
multiple areas of the brain may account for the following clinical
symptoms:
- Frontal lobe: Cerebral blood flow appears reduced,
particularly in frontal brain regions and is more like that seen in a 7
week-old child. This area is more involved than other brain parts. It
is necessary for mood and emotion.
- Caudate: much smaller than normal; involved in cognition, awareness and behavior
- Putamen: no anatomical change; necessary for movement
- Temporal lobe (limbic system): no anatomical change; needed for memory, learning, emotion, behavior.
- Cerebellum: reduction in some cell populations; needed for equilibrium and balance.
- Hippocampus: no anatomical change; necessary for information processing.
- Substantia
Nigra: marked reduction in the pigment, melanin, and degeneration of
cells; necessary for movement and critical thinking
- Medulla
(Brain stem): strong evidence of brain stem immaturity, leading to
problems with the autonomic nervous system, such as sleep, salivation,
breathing, heart rate, swallowing, bowel motility, blood circulation in
hands and feet, and reduced sensitivity to pain.
- Neurotransmitters: reduced. These include:
- Dopamine - necessary for movement and critical thinking,
- Acetylcholine - necessary for memory, cognition, movement control, and
- Glutamate - necessary for brain plasticity, important in seizures and cell death.
What has research found?
Rett Syndrome was previously described as a neurodegenerative disorder,
with very poor prognosis and little potential for learning. Scientific
studies have now identified Rett Syndrome as a disorder of
neurodevelopmental arrest, which begins shortly before or after birth
at a critical time of brain and synapse formation.
How do we know that RTT is a condition of developmental arrest?
- Supportive Clinical Evidence
- Early onset
- Normal head size at birth
- Low muscle tone
- Weak cry and poor suck
- Improved learning and gaining new skills during school age period
- Supportive Neurobiological Evidence
- Small brain (12-33% reduction)
- No malformations, storage, demyelination, infection or gliosis
- Dendritic arborizations, cell differentiation and neuronal growth affected
- Small neurons with increased neuronal packing, migration not affected
- Thinning of hippocampus
- Significant involvement of caudate nucleus
- Decreased melanin (pigment) in substantia nigra
- Lack of mature olfactory (smell) neurons
These studies reverse the previous hypothesis of brain degeneration,
opening doors to educational programs and therapies that could help.
Studies have raised speculation that the primary conduction abnormality
may be influenced by neurotrophic (growth) factors responsible for
maturation of the heart and central nervous system. It is felt that
these same neurotrophic factors may drive changes in the intestinal
tract. These studies pave the way for treatments that will ultimately
lead to a better way of life for girls with RTT.
What are some other research findings in RTT?
- Autonomic Findings
- Disorganized breathing
- Vasomotor changes (blue hands and feet)
- Vacant spells
- Constipation 90%
- Abdominal distention (bloating) 50%
- Biochemical Findings
- Elevated levels of beta-endorphins in cerebrospinal fluid (CSF)
- Decreased levels of dopamine & norepinephrine metabolites in (CSF)
- Cardiovascular Findings
- Prolonged QT syndrome
- Immaturity of the atrio-ventricular conduction system (heart)
- Nutritional Findings
- Growth failure has many causes, but has a strong basis in nutritional deficit.
- Progressive weight and height failure despite aggressive nutritional rehabilitation.
- Repetitive involuntary motor movements are not associated with increased energy expenditure.
- Sleeping
metabolic rates are low and are consistent with features of
malnutrition; these findings can be reversed with nutritional support
- Deficits in lean body mass persist despite aggressive refeeding regimens.
- Deficits in lean body mass may be associated with increased rates of amino acid oxidation and urea recycling.
- Preliminary
data suggest that the intestinal absorption of calcium and vitamin D
status are normal in RTT, despite the presence of reduced bone mineral
density.
- Oropharyngeal dysfunction and gastroesophageal dysmotility are found in 100% and 69% of Rett syndrome girls, respectively.
- Abnormalities
of oropharyngeal dysfunction include poor tongue mobility, reduced
oropharyngeal clearance, and laryngeal penetration of liquid &
solid food during swallowing.
- Esophageal dysmotility,
including abnormal wave patterns, delayed emptying, atony,
gastroesophageal reflux; gastric dysmotility, including diminished
gastric peristalsis or atony, and gall bladder dysfunction.
- Neurophysiological Findings
- Seizures are reportedly a common problem
- Prolonged
video/EEG/polygraphic studies confirm that the occurrence of epileptic
seizures is overestimated in Rett syndrome. Many events were frequently
reported as typical seizures but were not associated with EEG severe
discharge; these events include twitching, head turning, staring,
laughing, pupil dilatation, breath holding, and hyperventilation.
Actual seizures may be under-recognized.
- No one
characteristic seizure type has been identified in Rett syndrome; both
focal and generalized electrographic seizures are recorded. Video/EEG
monitoring may be necessary to provide definitive information regarding
the need for anticonvulsant therapy.
- Neuropathological Findings
- Morphologic
(anatomical) features are unique, with only decreased brain weight
being consistently present. The brain is preferentially involved in
this altered growth; other organ weights are appropriate for the
individual's height.
- No consistent evidence of a degenerative, inflammatory or ischemic process.
- No evidence of a progressive change in brain morphology over time. MRI and EEG studies support this observation.
- Best
hypothesis to fit the fact that there is no recognizable disease
process is that RTT seems to be the result of a maturational arrest of
brain development. Golgi studies suggest that arrested brain
development affects dendritic size in selected brain regions, namely
the frontal, motor, and limbic regions.
- Alterations in
numerous neurotransmitters have been observed, but no evidence
suggesting that these represent the primary defect.
- Is mitochondrial disease a secondary effect in RTT?
- No reproducible evidence of mitochondrial dysfunction exists.
- Epidemiology And Survival
- The
prevalence of Rett syndrome is 1 per 22,800 (0.44/10000) females aged
2-18 years of age as determined in the Texas Rett Syndrome Registry.
Studies in Sweden yielded a prevalence rate of 1:10,000.
- Rett syndrome has been reported in all races and ethnic groups.
- Rett
individuals have an estimated 70% survival at age 35 years; this
contrasts sharply with an estimated 27% survival at 35 years for
severely retarded individuals.
- The majority of deaths in Rett syndrome are either sudden and unexpected or secondary to pneumonia.
- This information is just a small part of The Rett Syndrome Handbook
- Audible swallowing at any time
- Severe dysfunction of swallowing with air swallowing apparent during eating or drinking
- Abdominal distention, usually following feedings or episodes of hyperventilation and breath holding
- Frequent burping (may be beneficial)
- Large amounts of gas passed through the rectum
What happens when she hyperventilates?
Deep breathing expels more carbon dioxide from the body than usual, so
her hyperventilation causes her carbon dioxide level to fall. Carbon
dioxide is one of the body’s normal waste products carried in the
blood. Its purpose is to maintain the acid/alkali balance so that cells
can function normally. When her carbon dioxide level falls, cells
cannot function normally. Hyperventilation may cause her to feel dizzy
and her fingers to tingle.
What happens when she holds her breath?
When she holds her breath, her oxygen level in the bloodstream falls. This may cause her to feel faint.
Are the abnormal breathing episodes or tremors related to seizures?
The abnormal breathing episodes can resemble epileptic seizures, but
they are not. Sometimes, what is thought to be a seizure is not, and
some seizures may fail to be recognized when she is asleep or even
awake. Vacant spells are brief interruptions of awareness that may
resemble seizures but are not. Will she always breathe this way?
For the majority of girls, irregular breathing patterns become less noticeable as they get older.
What should we do about her irregular breathing?
Although episodes of breath holding produce great anxiety for parents
to watch, they are always followed by regular breathing. Observing the
irregular breathing can cause great concern, but experts in RTT
recommend a low key approach, taking comfort in the fact that girls do
become accustomed to the irregular breathing and regular breathing will
soon return. While it may seem like forever, it is important to stay
calm and in control.
How can breathing be so abnormal when she is awake and normal when she sleeps?
In Rett syndrome, irregular breathing occurs only when she is awake and
does not usually occur during sleep. When she is awake, the periods of
abnormal breathing result from probable immaturity of neurons
regulating voluntary control of breathing mechanisms. During periods of
sleep, automatic breathing systems prevail allowing her to breathe
regularly and continuously. When abnormal breathing is seen in some
girls with RTT during sleep, it is of the obstructive type, usually
from enlarged adenoid/tonsils. Airway obstruction may be caused by
mechanical problems in the breathing passages. Mouth breathing, snoring
and frequent ear infections may be signals that your daughter has a
problem which should be evaluated by an ear, nose, and throat
specialist.
Are the breathing problems dangerous to her health?
They can be alarming to watch, and may make her somewhat uncomfortable,
but they are not felt to cause permanent damage. Cessation of breathing
during sleep is not typically seen in RTT. However, if your child stops
breathing for short periods of time while asleep, you should talk with
her physician. She may need testing to rule out airway obstruction.
This is a separate problem from RTT, for which there is treatment.
How can I tell if she is swallowing air?
Air swallowing can be difficult to detect or may be prominently
associated with breath holding. Air can be swallowed inadvertently in
significant amounts each time she eats. It can also occur throughout
the day in small amounts. Sometimes it is easy to hear air as it is
being swallowed. If her upper abdomen is distended shortly after she
eats it could be that she is swallowing air. Here are some signs and
symptoms associated with air swallowing: If a large amount of air stays
temporarily in the stomach, it will lead to sudden distention of the
upper part of the abdomen. The stomach stretches, creating significant
tension. If the girl with RTT is unable to burp or pass gas, the bowel
wall may become thin over time. This is especially true in individuals
who have a poor nutritional status.
If you suspect that she is swallowing air, there are a few things you
can do. Decrease the length of mealtimes if it appears she is
swallowing air while eating. Minimize stress and discomfort. Sit her in
an upright position after she eats to help her burp and decrease the
amount of gas in the stomach that is passed into the bowel. Keep on top
of constipation so that gas does not accumulate in the mid intestine.
In some situations, even the frequent use of enemas (not routinely
recommended) may be preferred to severe episodes of abdominal
distention.
If these measures are not adequate and her abdominal distention is
severe, you may need to ask the advice of her physician on more
aggressive methods. Early detection as well as consultation with a
gastroenterologist are extremely important to avoid progression of the
problem and to manage it as early as possible, thus preventing more
severe complications.
Should she have an electrocardiogram (ECG)?
By age 5, your daughter should have an ECG performed. If normal, it
should be repeated every other year. If abnormal, a cardiologist expert
in electrical function of heart should be consulted.
What can be done about heart irregularities?
If irregularities are noted on the electrocardiogram, a cardiologist
may be consulted. Nonspecific ECG changes probably do not warrant
medications, but prolonged QT syndrome may require attention.
Where do I go for more information?
Contact the International Rett Syndrome Foundation at 1 800 818 RETT,
or visit www.rettsyndrome.org We can connect you with many types of
informational resources: online, print, video, audio, as well as
connect you with others in your local area.
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