Fragile X Syndrome (FXS): Genetic Disorder

• Fragile X Syndrome (FXS) is a genetic disorder due to changes in the Fragile X Messenger Ribonucleoprotein 1 (FMR1) gene

• The FMR1 gene makes the FMRP protein which is needed for brain development, those with FXS do not produce this protein.

Prevalence

• FXS affects both males and females, although females typically have milder symptoms.
• Approximately 1 in 7,000 males and 1 in 11,000 females have been diagnosed with FXS.

Symptoms include

• Symptoms include developmental delays like not sitting, walking, or talking at the same age peers.
• Learning disabilities are a symptom of the syndrome.
• Social and behavior problems, such as avoiding eye contact, anxiety, trouble paying attention, hand flapping, and hyperactivity, are symptoms of FXS.
• Males with FXS usually have some degree of intellectual disability, ranging from mild to severe.
• Females with FXS can have normal intelligence or some degree of intellectual disability.
• Autism spectrum disorder (ASD) is more frequent in people with FXS.

Physical Features and Behavioral Characteristics

• Macroorchidism (large testes) is a symptom.
• Facial features include prominent ears, macrocephaly (large head), long face, prominent jaw and forehead, and high arched palate.
• Hyperextensible joints, flat feet, and soft skin can be characteristics of FXS.
• Average age diagnosis: 3 years.
• Speech and motor delays, behavioral difficulties like ADHD and anxiety are also symptoms.

Developmental Milestones

• Those with FXS may experience delays in walking, talking, toilet training, learning, and making eye contact.
• Sensory difficulties like those affecting sight, hearing, smell, taste, and touch are also symptoms.

Associated Medical Complications

• Frequent otitis media is a complication.
• Other complications include strabismus (crossed eyes), seizures, sleep disorders, GE reflux, sleep apnea, and loose stools.

Diagnosis

• FXS is diagnosed through a DNA blood test.
• A doctor or genetic counselor can diagnose FXS
• A diagnosis can provide a reason for a child's intellectual disabilities and behavior problems.
• Genetic testing is typically done in response to behavioral difficulties and potential physical features.
• Prenatal testing options: amniocentesis at 16 to 20 weeks or chorionic villus sampling (CVS) at 10 to 13 weeks which presents risk factors and is not routine.

Developmental and Behavioral Concerns

• Cognitive difficulties include issues with visuospatial skill, working memory, and processing sequential information and attention.

• Cognitive strengths include visual memory, simultaneous processing, and long-term memory.

• Full Scale IQ and adaptive function decreases with age, reflecting developmental difficulties; scores stabilize in adulthood.

• ADHD: 73% of males and 30%-63% of females are affected.

• Anxiety: 86.2% of males and 76.9% of females are affected.

• Hyperarousal with overreaction to sensory input is a symptom.

• Self-injurious behavior can start in the 1-3 age group, with aggression appearing in adolescence.

• Autism affects 50%-66% of males and 20% of females.

Treatment Approaches

• Early identification is important.
• Supportive therapies is a treatment approach.
• Educational intervention, treatment of medical problems (e.g., otitis media), behavioral modification/Applied Behavior Analysis, and psychopharmacology for behavior dysfunction (Stimulants) are all treatment approaches.
• Occupational therapy, physical therapy, and speech therapy should be included in an intervention program based on the child's specific needs.

Fragile X Syndrome (FXS) is a genetic disorder caused by changes in the FMR1 gene, which is essential for brain development. Symptoms include developmental delays, learning disabilities, and social and behavioral challenges. FXS affects both males and females, with varying degrees of intellectual disability.