TY - JOUR T1 - QUESTION 2 JF - Archives of Disease in Childhood JO - Arch Dis Child SP - 323 LP - 324 DO - 10.1136/adc.2008.154443 VL - 94 IS - 4 AU - Veronica B Kelly AU - A Salt Y1 - 2009/04/01 UR - http://adc.bmj.com/content/94/4/323.abstract N2 - You diagnose a 5-year-old boy with autistic spectrum disorder. His examination is unremarkable and there is no family history of learning difficulties. Should you perform a molecular genetic screen for fragile X?Clinical bottom lineFragile X syndrome is significantly more common in children with autism (2%) than in the general male population (0.05%). (Grade C)Approximately 50 children with autism would have to be tested to diagnose one child with fragile X syndrome. (Grade C)Earlier identification of fragile X syndrome enables earlier genetic counselling and more accurate prognostic information to be offered. (Grade D)In boys with a diagnosis of autism [population] and no family history of learning disability [negative test result] what is the risk of fragile X syndrome [outcome]?Searches were carried out using “Autism”, “Autistic spectrum disorder” combined with “FRAX” and “fragile X”.Primary sourcesPubMed: the search was limited to 1991–2008, as molecular genetic testing was routinely used to test for this condition from 1991 onwards. Thirty articles were retrieved and the abstracts were reviewed. Four relevant articles were included. … ER -