Conditions - Fragile x-syndrome

Question 1

fragile x definitions

Answer 1

• a group of genetic conditions that are all caused by changes that occur in the Fragile X Mental Retardation 1 (FMR1) gene — located on the X-chromosome (Wattendorf and Muenke, 2005)
• FMR1 gene
• On the long arm of the X-chromosome, an expansion of the triplet base pair (cytosine-guanine-guanine) occurs causing the X-chromosome to become “fragile”.
• Due to this, a decrease or absence in FMRP production, which is a protein that is extremely “important in early brain development” (p.282) because it regulates the production of other proteins that control how nerve synapses grow and change in response to learning (TNFXF, 2008).
• The FMR1 gene affects body functions, primary brain development–MR

Question 2

3 forms of fragile x

Answer 2

• Fragile X syndrome (FXS):
• “The most common cause of inherited mental impairment”.
• Characteristics range from person to person
• male vs. female: The prevalence: 0.4-0.8 per 1000 boys and 0.2-0.6 per 1000 girls.
• premutation (CGG60-200) vs. full mutation (CGG>200)
• Fragile X-associated tremor/ataxia syndrome (FXTAS):
• Some older premutation carriers, generally grandfathers of children with fragile X syndrome
• affects balance, tremor and memory
• Fragile X-associated primary ovarian insufficiency (FXPOI):
• Carriers of the FMR1 premutation are at risk for FXPOI
• infertility and early menopause

Question 3

more descriptions

Answer 3

The mutation is in the DNA of the X chromosome.

The gene appears in three forms that are defined by the number of repeats of a pattern of DNA called CGG repeats.

• Individuals with less than 60 CGG repeats have a normal gene.
• Individuals with 60-200 CGG repeats have a premutation which means they carry an unstable mutation which can expand in future generations.
• Individuals with over 200 repeats have a full mutation which causes fragile X syndrome. The number of repeats does not appear to affect the severity of the symptoms.

It’s not really the CGG’s—The methylation stops the synthesis of FMRP and the absence of FMRP causes fragile X syndrome.

Question 4

physical appearance

Answer 4

• Large ears
• Long, narrow face
• Prominent forehead
• Prominent, square chin
• Large testicles
• High palate (roof of mouth)
• Hand calluses
• Seizures
• Eye problems(Ear infections)
• Loose connective tissue
• Hyperextensible joints
• Flat feet
• Mitral valve prolapse (a leaky heart valve)

Question 5

areas affected

1. cognition
2. behavior
3. sensation
4. speech and language
5. motor skills
6. living skills

Answer 5

1. Cognition:
   
   • Developmental delay/Mental retardation/Learning disabilities
2. Behavior:
   
   • Hand flapping, lack of eye contact or gaze avoidance, hyperactivity, inattention, aggression, anxiety, behavior problems, Autistic-like features: Hand biting/Hand flapping/Poor eye contact
3. Sensation:
   
   • Tactile defensiveness
4. Speech and language:
   
   • Repetitive speech, talkativeness, echolalic (parrot-like), cluttered, poor topic maintenance, poor perseveration on one idea
5. Motor skills:
   
   • Loose connective tissues & low muscle tone  lack coordination and have poor posture, mobility, energy, strength and effort
6. Living skills:
   
   • Shyness, social anxiety
   • Mental health issues
   • Difficulty adjusting to change; Poor self-care

Question 6

strengths

Answer 6

Male: simultaneously process, verbal label object, possess a large single-word vocabulary, visually match and have a good memory for movie and videos

Female : good vocabulary, good short-term visual memory, good reading and spelling