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. INTELLECTUAL DISABILITY 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)

Synonyms: Fragile X-F Mental Retardation Syndrome FRAXA Syndromes Martin Bell Syndrome Mental Retardation, X-Linked, Associated With Fragile Site Fraxe Syndromes, Fragile X FRAXE Syndromes Marker X Syndromes Fra(X) Syndrome Martin-Bell Syndrome FRAXA Syndrome Syndrome, Martin-Bell FRAXE Syndrome Fragile X Syndrome Mental Retardation, X-Linked, Associated With Marxq28 Marker X Syndrome Syndromes, Marker X Fragile X Syndromes Mar (X) Syndrome X Linked Mental Retardation and Macroorchidism Syndromes, FRAXA Syndromes, FRAXE X-Linked Mental Retardation and Macroorchidism Syndrome, FRAXA Fragile X Mental Retardation Syndrome Syndrome, Marker X Syndrome, FRAXE Syndrome, Fragile X