Definition of fragile X syndrome
- … most children with fragile X syndrome have other characteristic traits, including anxiety, hyperactivity, and a number of behaviors that are often seen in autism.
- —Mark Cohen
- The defective gene responsible for fragile X syndrome is carried on one leg of the X chromosome, the chromosome that helps determine the sex of a child.
- —Elaine T. Cicora
- Female carriers of fragile X syndrome as a group exhibit wide variation in degree of phenotypic involvement. Some heterozygotes are cognitively unaffected, others have learning disabilities, and approximately one third have significant mental impairment and an IQ score of less than 85.
- —Annette K. Taylor, MS, PhD et al.