Fragile X Syndrome is a genetic defect. It is the absence of a functional fragile X gene (FMR1) that shuts down the
production of a special protein in the brain needed for normal cognitive development. Without this protein, children with the
syndrome will never learn normally, despite hours of therapy and rehabilitation.  Fragile X syndrome is a hereditary disorder
which causes a wide range of mental impairment, from mild learning disabilities to severe mental retardation.   Fragile X
syndrome is the leading hereditary cause of developmental disabilities.  In addition to mental impairment, fragile X syndrome
is associated with a number of physical and behavioral characteristics.

In 1991, scientist discovered the gene called (FMR1) which causes Fragile X. Fragile X Syndrome, a defect in which the
absence of a functional fragile X gene (FMR1) shuts off production of a special protein in the brain needed for normal
cognitive development. Cognitive development is defined as thinking, problem solving, concept understanding, information
processing and overall intelligence. Without this protein, children with the syndrome will never learn normally, despite hours
of therapy and rehabilitation.  

The exact frequency of Fragile X is unknown.  The full mutation appears in approximately 1 in 2000 males and 1 in 4000 to
6000 females.  The carrier, usually a transmitting male,  passes the pre-mutation gene (FMR1) to all their daughters, but none
of their sons. Females are also be affected, approximately 30% of females with full mutations are mentally retarded, and their
level of retardation is, on average, less severe than that seen in males. Approximately one third of female carriers of full
mutation gene (FMR1) will have mild to moderate mental disabilities. Each child of a carrier woman has a 50% chance of
inheriting the gene. The Fragile X pre-mutation gene can be passed silently down through generations in a family before the
syndrome affects one child. A DNA blood test identifies both carriers and affected individuals.

Some of these children may have certain facial features which include everted ears and elongated faces. Behaviors may
include hyperactivity and autistic characteristics may be present. Such as chewing on skin, clothing, or objects, which may
be connected to sensory processing problems and anxiety.

Sensory processing problems may manifest themselves as tactile defensiveness, such as oral motor defensiveness, sensitivity
to sound or light, and poor eye contact. About 90% of boys with fragile X syndrome are reported to have some type of
sensory defensiveness.  Tantrums may be a result of anxiety and a feeling of being overwhelmed. Crowds and new situations
may cause boys to whine, cry, or misbehave, in attempts to get out of the overwhelming settings.

Like many developmental disorders such as autism, Fragile X syndrome include all ranges of impairment from profound
mental retardation (MR) to mild learning difficulties, as well as developmental delays, autistic-like behavior, hyperactivity and
other behavior disturbances.  

The poor eye contact and difficulty sustaining a conversation can cause many social weaknesses. Perseverative speech and
self-talk may be symptoms of anxiety.

Some behaviors that overlap with the diagnosis of autism are often reported. The majority of children with fragile X
syndrome do not have all the characteristics of autism, but about 15% to 33% are diagnosed as autistic. More often, children
have "autistic-like" features, such as poor eye contact, hand flapping, and poor social skills.
Girls with the full mutation of the fragile X gene appear to have some specific areas of concern in the area of behavioral and
emotional difficulties. Shyness, anxiety, depression and difficulties with social contacts are most often mentioned as
characteristics of girls with fragile X.

Some behaviors include:

•        Mental retardation

•        Hyperactivity

•        Short attention span

•        Tactile defensive / touch sensitivity

•        Hand-flapping

•        Hand-biting

•        Poor eye contact

•        Repetitive Speech

•        Double Jointed

•        Large or prominent ears

•        Large testicles

•        Simian crease - a single horizontal crease on the palm instead of the usual two

What is the Fragile X gene (FMR1)?

The FMR-1 gene is located on the X chromosome. This gene is responsible for instructing the cell to make FMRP, a protein
assumed to be essential for normal brain functioning.

Fragile X is the leading form of autism: 90 % of Fragile X patients have autistic features, 50% of pre-school Fragile X
children meet autism diagnostic criteria, and 6% of all autistic individuals turn out to have fragile X. Fragile X also gives rise
to anxiety disorders, attention deficit hyperactivity disorder, psychosis, obsessive-compulsive disorder, and many other

A Cure for Fragile X?

There is currently no cure for Fragile X Syndrome, although appropriate education and medications can help maximize the
learning potential of each child. However, most boys and many girls remain significantly affected throughout their lives. The
need for treatment and special education are significant. The need for research aimed at treatment is urgent.  

Recent significant progress has been made in understanding mechanisms and developing potential treatments for inherited
diseases that are caused by a single gene, such as Fragile X.

Current medical research focuses on: Gene Therapy - studying the gene that causes Fragile X in order to determine whether a
healthy gene may be inserted into the cells of affected individuals, thereby replacing the mutated, ineffective gene.

Protein Replacement Therapy - studying the protein product that is lacking due to the mutation, in hopes that the protein may
be supplemented from an external source.

Psychopharmacology - treating the symptoms of the disorder with medications.

Many researchers believe that medical treatment, when it becomes available, will be able to help Fragile X individuals of all
ages. Experts think that the missing FMR protein has a regulatory function in the brain, rather than a structural function, and
that this protein is needed throughout a person's life.
Fragile X - What is fragile X - fragile X behaviors.  Bright Tots - Information on child development - Autism information.
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