In most cases, the child's developmental delay will be static, but the physician should pay particularly close attention if it appears to be progressive. Children with GDD reach their milestones slowly, but they should not be losing any milestones. If they do, think about a missed phenylketonuria diagnosis or similar disorders.
During the physical exam, look closely for dysmorphic features. Most normal individuals will have three or four dysmorphologies, but children who have five or more may have a brain disorder.
Make sure also that the developmental delay isn't caused by a chronic organ-system problem, such as occult renal disease, and consider genetic causes as well.
Dr. Bennett recommended all children with developmental delay get a high-resolution banded karyotype, a DNA test for fragile X syndrome, and a urine metabolic screen.
An MRI may be indicated in some children, although these often come back with a nondescript finding such as “cerebral dysgenesis,” he said.
And an EEG, while not routine, should be considered for any child in whom there is a high index of suspicion for atypical seizures.