Problems in the diagnosis of fragile X syndrome in young children are still present

Fragile X syndrome is common; its prevalence approaches 1 per 5,000, Fragil e X syndrome is the most common inherited cause of mental retardation. Many professionals must deal with fragile X individuals on a daily basis. Howev er, despite the diverse information on the epidemiology, clinical features, unique pattern of inheritance, cytogenetic, and molecular diagnosis and sc ales for the diagnosis of this syndrome, the diagnosis of fragile X syndrom e is still not always made by the patients' specialists. Here we present th e difficulties in the diagnosis of fragile X syndrome in 11 children under 8 years of age, 10 boys and one girl. We report data on initial symptoms, b ehavioral features, and physical and mental development before molecular st udies were considered. The possible causes for the diagnosis delay were mul tiple: nonspecific features (e.g,, macrocephaly, overgrowth, obesity), unre markable physical examination, family history apparently noncontributory, a nd lack of or delayed molecular testing, Careful clinical examination of yo ung children and DNA screening in case of doubt, and education of professio nals in medical specialty areas, behavioral sciences, education, and other fields are recommended. (C) 2001 Wiley-Liss,Inc.