Etiologic evaluation in 247 children with global developmental delay at Istanbul, Turkey

OBJECTIVE: Developmental delay is a common pediatric problem, having a great number of underlying causal factors. Etiologic diagnosis is important for providing information about pathogenesis, prognosis, recurrence risk and specific medical interventions. The aim of this study was to determine the etiologic yield and spectrum of a consecutive cohort of global developmentally delayed children. METHODS: This retrospective study included all children younger than 5 years of age with global developmental delay referred to a single university-based ambulatory pediatric neurology clinic for initial evaluation over a 14-month period from January 1997. Diagnostic studies consisted of history, physical examination, electroencephalography and selected investigations including neuroimaging, screening for metabolic disease, karyotype and fragile X testing. RESULTS: In the study 247 patients (136 males) with a mean age of 24.2+/-20.3 months were evaluated. Etiologic diagnosis was determined in 64 per cent of the patients classified under the following categories: perinatal complications (21 per cent), cerebral dysgenesis (18 per cent), chromosomal abnormalities (9 per cent), genetic/dysmorphic syndromes (3 per cent), metabolic disorders (4 per cent), hypothyroidism (4 per cent), neurocutaneous syndromes (3 per cent), intrauterine infection (2 per cent). Etiology was unknown in 36 per cent of the patients. Two laboratory tests (neuroimaging and cytogenetic analysis) together with the history and physical examination were most helpful in determining the etiologic diagnosis. CONCLUSION: This study suggests that optimal management of global developmentally delayed children and their family should involve a comprehensive evaluation.