Retrospective diagnosis of congenital infection by cytomegalovirus in the case of one infant

10-15% of asymptomatic congenital infections by cytomegalovirus (CMV) in the neonatal period develop persistent problems with varying degrees of severity, fundamentally involving neurological disorders, neurosensory hypoacusis and hypovision, which appear from the age of 6-9 months onwards, when a diagnosis is no longer possible. The PCR (polymerase chain reaction) technique can detect DNA of CMV in blood samples on filter paper used for screening hypothyroidism and metabolic pathologies that were kept from the neonatal period. A child aged 3 years and 8 months with delayed intrauterine growth, autism, mental retardation, microcephalus and neurosensory hypoacusis; periventricular calcifications, leukoencephalopathy and bilateral malformation of the temporal lobe; and a diagnosis of congenital CMV confirmed by detection of DNA by PCR in the blood sample on filter paper saved from the neonatal period. The retrospective study of congenital infection by CMV should be considered when faced with severity and varying association of delayed intrauterine growth, microcephalus, neurosensory hypoacusis, chorioretinitis, mental retardation, autism or other behavioural disorders, intracranial calcifications, encephaloclastic alterations, leukoencephalopathy, cortical dysplasia and malformations of the temporal lobe and the hippocampus. Since the filter papers from neonatal screening are not kept for ever, perhaps the idea of doing so ought to be considered, given the possibilities they offer for retrospective studies.