What is Rett Syndrome?
Rett syndrome is a
postnatal neurological disorder seen almost always in girls, but can be rarely seen in boys. It is not a degenerative disorder.
Rett syndrome is caused
by mutations on the X chromosome on a gene called MECP2. There are more than
200 different mutations found on the MECP2 gene. Most of these mutations are
found in eight different “hot spots.”
Rett syndrome strikes
all racial and ethnic groups, and occurs worldwide in 1 of every 10,000 to
23,000 female births.
Rett syndrome causes
problems in brain function that are responsible for cognitive, sensory,
emotional, motor and autonomic function. These can include learning, speech,
sensory sensations, mood, movement, breathing, cardiac function, and even
chewing, swallowing, and digestion.
Rett syndrome symptoms
appear after an early period of apparently normal or near normal development
until six to eighteen 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. Soon, stereotyped hand
movements such as handwashing, gait disturbances, and slowing of the normal
rate of head growth become apparent. Other problems may include seizures and
disorganized breathing patterns while she is awake. In the early years, there
may be a period of isolation or withdrawal when she is irritable and cries
inconsolably. Over time, motor problems may increase, but in general,
irritability lessens and eye contact and communication improve.
Rett syndrome can
present with a wide range of disability ranging from mild to severe. The course
and severity of Rett syndrome is determined by the location, type and severity
of her mutation and X-inactivation. Therefore, two girls of the same age with
the same mutation can appear quite different.
Rett syndrome is
most often misdiagnosed as autism, cerebral palsy, or non-specific
developmental delay. In the past, making the correct diagnosis called not only
for a long list of diagnostic tests and procedures to rule out other disorders,
but it also took from months to years waiting to confirm the diagnosis as new
symptoms appeared over time. Today, we have a simple blood test to confirm the
diagnosis. However, since we know that the MECP2 mutation is also seen in other
disorders, the presence of the MECP2 mutation in itself is not enough for the
diagnosis of Rett syndrome. Diagnosis requires either the presence of the
mutation (a molecular diagnosis) or fulfillment of the diagnostic criteria (a
clinical diagnosis, based on signs and symptoms that you can observe) or both.
Below is a list of labs to share with your ordering physician that can do the
MECP2 sequencing + deletion analysis, and the list of diagnostic criteria.
Testing and Diagnosis
Rett syndrome is most often misdiagnosed as autism, cerebral palsy,
or non-specific developmental delay. In the past, making the correct
diagnosis called not only for a long list of diagnostic tests and
procedures to rule out other disorders, but it also took from months to
years waiting to confirm the diagnosis as new symptoms appeared over
time. Today, we have a simple blood test to confirm the diagnosis.
However, since we know that the MECP2 mutation is also seen in other
disorders, the presence of the MECP2 mutation in itself is not enough
for the diagnosis of Rett syndrome. Diagnosis requires either the
presence of the mutation (a molecular diagnosis) or fulfillment of the
diagnostic criteria (a clinical diagnosis, based on signs and symptoms
that you can observe) or both. Below is a list of labs to share with
your ordering physician that can do the MECP2 sequencing + deletion
analysis, and the list of diagnostic criteria.
- See more at:
http://www.rettsyndrome.org/understanding-rett-syndrome/about-rett-syndrome/testing-diagnosis#sthash.CABcoha0.dpuf
