2. Most commonly inherited cause of mental
impairment
1 in 3600 males and 1 in 4000 to 6000 females are
affected
Caused by mutated FMR1 gene on the X
chromosome
Gene discovered in 1991
No cure but certain therapies can help
3. Intellectual disability
Significant in the majority
Learning disability to mental retardation to autism
Usually strengths and weaknesses
Good memories for pictures and visual patterns
Learn in simultaneous fashion instead of sequential
Can be hard to teach reading
Speak in rapid bursts, repeat words or perservation
Physical features
Large ears
Long face with prominent chin
4. Connective tissue
Flat feet
Ear infections
Double jointed
Behavioral
ADD/ADHD
Mood swings and temper tantrums
Speech disorders
Poor eye contact
Extreme hypersensitivity to environment
Strange responses to visual/auditory stimuli and touch
Very friendly and social
5. Intellectual disability
usually milder than in males
Significant disability seen in around 1/3 of females
Many are disabled in math but excel in reading and spelling
1/3 have symptoms like schizophrenia
Ex: prefer social isolation
Physical and behavioral problems
Same as in males but usually milder
6. Fragile X Mental Retardation 1 (FMR1) gene on
the end of the X chromosome
Normally about 30 repeats of CGG
Premutation: 55-200 repeats
Full mutation: more than 200 repeats
7. Encodes for fragile x mental retardation 1 protein
Protein appears in many tissues and throughout
the brain
Role in synapse development and neuroplasticity,
assisting in learning and memory
Shuttles mRNA in cell between nucleus and protein
assembly areas
Helps control when mRNA is used to build proteins
May be found in lungs, kidneys, liver, and spinal
chord but other proteins called FXR1 and FXR2
may compensate here
Exact role is still unknown
8. Do not show typical signs
Most are intellectually normal with mild physical
features
May have some emotional problems
Can cause other health related problems
Can have affected children
9. Because of repetitions of CGG, gene become very
unstable
Under microscope it looks broken or fragile
Gene is silenced – no protein is made
Results in full onset of effects
10. From the father:
Can only pass chromosome on
to daughter
Will only cause premutation in
daughter, even if he has the full
mutation
From the mother:
Can pass chromosome to either
son or daughter
Can expand from premutation
chromosome to fully mutated
chromosome (chance of this
occurring increases with each
generation)
11. Women
have 2 X chromosomes
Only 1 is active in each cell because of X inactivation
– it’s a coin toss and can differ between cells
If they inherit 1 mutated X and 1 normal X, cells have
a 50/50 chance of being affected
Different ratios of affected to unaffected cells in the
brain create varying degrees of Fragile X symptoms
12. Men
have 1 X chromosome and 1 Y chromosome
All cells use same X chromosome
If mother passed on mutated X, all cells will show
mutation
If mother passed on premutated X, cells could show
mutation if it becomes full mutation
If mother passed on normal X, no cells will show
mutation
13. There is no cure, only treatment.
Research is actively being conducted.
Educational options
Therapeutic options
Medication options
14. Parents, teachers, and psychologists can develop
an Individualized Education Plan (IEP)
Placement depends on severity of Fragile X
Generally three options:
Full inclusion in a regular classroom.
Inclusion with "pull-out" services
Full-time, special education classroom
15. Speech-language therapists
Improve pronunciation, slow down speech, etc
Occupational therapists
Help with tasks, daily activities, and career choice
Physical therapists
Motor control
Behavioral therapists
Identify distressing situations and help to prevent and
cope with them
16. Treat symptoms
Some have serious risks
Examples:
Ritalin for ADD
Prozac for aggression
Melatonin for sleep disturbances
Lithium carbonate for mood instability
17. Caused by FMR1 gene mutation
No artificial protein to replace FMR1 protein
Most commonly inherited cause of mental
retardation