Fragile X Syndrome: The Journey from Genes to Behavior

Case 3.1: Harold Harold is a 6-year-old boy recently evaluated by his pediatrician for developmental delay and autistic-like features. Harold’s mother reported early problems with speech production, hyperactivity, and aggressive outbursts. More recently the behavioral problems have intensified, and Harold has begun to hand bite. On physical examination, the pediatrician notes that Harold has a slightly longer face, larger ears, and more prominent jaw than would be expected for a boy his age but nothing too unusual. A family history reveals that Harold’s sister and maternal cousin, both females, have mild learning di‰culties including attention problems, chronic shyness, and social anxiety. Molecular analysis revealed fragile X syndrome.