Tests for Some Causes of Intellectual Disability
Suspected Cause | Indicated Tests |
|---|---|
Single major anomaly or multiple minor anomalies Family history of cognitive disability | Chromosomal microarray analysis Cranial MRI* Possibly exome sequencing |
Idiopathic hypotonia | HIV screening in high-risk infants Nutritional and psychosocial history Urine and serum amino acid and organic acid analysis and enzyme studies for storage diseases or peroxisomal disorders Muscle enzymes Comprehensive metabolic panel (includes albumin, alkaline phosphatase, aspartate aminotransferase, total bilirubin, blood urea nitrogen, calcium, cholesterol, creatinine, glucose, phosphorus, total protein, and uric acid) Bone age, skeletal x-rays |
Seizures | Electroencephalography Cranial MRI* Blood calcium, phosphorus, magnesium, amino acids, glucose, and lead levels |
Cranial abnormalities (eg, premature closure of the sutures, microcephaly, macrocephaly, craniostenosis, hydrocephalus) Cerebral atrophy Cerebral malformations Central nervous system hemorrhage Tumor Intracranial calcifications due to toxoplasmosis, cytomegalovirus infection, or tuberous sclerosis complex | Cranial MRI* TORCH screening Urine culture for virus Chromosomal microarray analysis |
* Cranial MRI is done after neurologic consultation. | |
SMA = sequential multiple analyzer; TORCH = toxoplasmosis, other pathogens, rubella, cytomegalovirus, herpes simplex. | |