[Evaluation and diagnosis of patients with developmental delay: standardised protocols from the paediatric point of view].

INTRODUCTION AND AIMS: The identification of the causes of mental retardation (MR) is of great importance because of the consequences it has in the intervention, prognosis, knowledge of risk of recurrence and its prevention. The purpose of this review is to provide a global evaluation of the child with developmental delay or with MR in day-to-day clinical praxis of the neuropaediatrician who has to put aetiological diagnosis in practice.

DEVELOPMENT: To this end we conduct a review of the evidence-based guidelines published by the leading groups of experts that assess the weight of diagnostic tests in the initial evaluation of children with MR and propose an algorithm that helps the clinician to make decisions.

CONCLUSIONS: A good patient record including the familial and personal history, the examination and observation of behaviour is essential before starting the laboratory and imaging tests in a rational manner. At the outset, cytogenetic and molecular genetic studies are indicated to study fragile X syndrome and neuroimaging, preferably magnetic resonance, should be employed above all when anomalies are observed in the examination. Ophthalmologic and auditory evaluation is recommended in all cases. Routine metabolic screening is not indicated at the outset; studies to investigate thyroid (T4 and TSH) and other metabolic pathologies can be considered when the child has not been subject to neonatal metabolic screening or when there is clinical evidence of it. Routine electroencephalogram studies are not recommended, but can be considered if suggested by the clinical history. Likewise, the clinician may consider a study for toxins, if the clinical history suggests it, and a genetic study of Rett syndrome, in the case of girls with MR that cannot be accounted for by other causes.