Fragile X Syndrome

A condition characterized genotypically by mutation of the distal end of the long arm of the X chromosome (at gene loci FRAXA or FRAXE) and phenotypically by cognitive impairment, hyperactivity, SEIZURES, language delay, and enlargement of the ears, head, and testes. MENTAL RETARDATION occurs in nearly all males and roughly 50% of females with the full mutation of FRAXA. (From Menkes, Textbook of Child Neurology, 5th ed, p226)

Mutation

Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.

Arm

The superior part of the upper extremity between the SHOULDER and the ELBOW.

Language

A verbal or nonverbal means of communicating ideas or feelings.

Mutation

Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.

Child

A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.