Fragile X Syndrome

• Second most common cause of mental retardation after Down’s Syndrome: 9.92/1000
• More common in males
• Affected males have a fragile site on the X chromosome when chromosomes are grown in a folate-deficient environment
• Typical phenotype (appearance) is:
• Long face
• Big Head
• Floppy Ears
• Macro-orchidism (a very rare condition, characterized by asymptomatic, benign, bilateral testicular enlargement)
• IQ is between 35 and 50
• Seizures may occur
• Autism occurs in 16%
• Microcephaly may be present

 

Diagnosis

• DNA diagnosis is now available