This document summarizes Fragile X syndrome. It is caused by a mutation on the FMR1 gene on the X chromosome, which normally produces a protein involved in brain development and function. Fragile X syndrome is characterized by intellectual disabilities and certain physical traits. While there is no cure, treatment aims to manage symptoms through educational and therapeutic interventions, as well as medication in some cases.

1. Kelsey Sokol

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