The pediatrician and diagnosis of developmental delay

In this study we report the retrospective analysis of a diagnostic work-up, comparing the yield of causal diagnoses in 45 children with developmental delay (DD: intelligence quotient (IQ) 70-80) and 68 with mild mental retardation (MMR IQ 50-70). We also compare associated medical problems in the study population with those found in a mainstream reference population. Results: No differences in diagnostic yield between the two groups were seen. Causal diagnoses were found in 55% of the children in both groups and were equally distributed over hereditary, acquired and familial causes. In 27% genetically and/or clinically defined syndromes were found. In most cases clinical history and multidisciplinary physical examination were crucial for establishing the diagnosis. Associated medical problems are frequent in both groups (35%) and the prevalence of epilepsy, hearing loss, growth retardation and behavioural disorders is higher than in a mainstream reference population. Referral for motor rehabilitation (70%), psychiatric treatment (15%) and genetic counselling (60%) followed the diagnostic process. Conclusion: In this study in one out of two children a cause was found. The yield of causal diagnoses in children with an IQ of 70-80 (DD) was equal to that in children with an IQ of 50-70 (MMR). Associated problems were found more often than in healthy children and caused additional restrictions. A multidisciplinary approach is recommended and should not be restricted to children fitting the definition of mental retardation. A prospective study is needed to evaluate the diagnostic yield with newer genetic and neuroimaging techniques