Recommended clinical work-up for autism spectrum disorder at the centres represented by the authors*
| Specialty | Indication for testing | Test |
|---|---|---|
| Genetics (9), (12), (22) | All | Genome-wide microarray, fragile X syndrome (FMR1 gene) |
| Head circumference > +3 SD | PTEN gene | |
| Concerns about other conditions | Tuberous sclerosis and others as indicated | |
| Consider for females with intellectual disability | MECP2 gene | |
| Neuroimaging (23), (24) | Complex ASD (clinical focal findings, major dysmorphology, micro- or extreme (≥ 4 SD) macrocephaly, skin lesions, seizures, focal EEG abnormalities, motor regression) | Brain magnetic resonance imaging and/or spectroscopy† |
| Metabolic (25) | If clinically indicated (e.g., severe intellectual disability and seizures, developmental regression) | Levels of venous blood gas; serum ammonia; lactate, pyruvate and uric acid; plasma amino acid; total, free and acylcarnitine; urine organic acids, mucopolysaccharides |
| General medical | Should be considered, especially for developmental delay | T4, TSH, complete blood count, ferritin level |
| If indicated (e.g., presence of lead in the area where the family lives, evidence of pica) | Lead level | |
| If neuroleptic therapy is considered | Fasting lipid profile, glucose, HbA1c, electrocardiogram | |
| Gastroenterology (26) | Pain after meals, night awakening despite good sleep hygiene | Rule out gastroesophageal reflux disorder |
| High eosinophil count | Rule out eosinophilic esophagitis | |
| Bloating (2 or 3 times per wk for more than 2 wk) | Tissue transglutaminase levels (to rule out celiac disorder) | |
| Failure to thrive, weight loss | Serum albumin, total protein, calcium, vitamin D levels | |
| Neurology (27) | Suspected seizures, documented regression | EEG (ideally sleep record) |
| Psychology or psychiatry | Mental health concerns (e.g., anxiety, mood) | Comorbidity assessment |
| Psychology | Need to establish mental age | Cognitive and adaptive behaviour assessment‡ |
| Learning concerns | Cognitive, academic assessment (may include evaluation of memory and executive functioning) | |
| Speech-language pathology | Speech or language concerns | Speech-language assessment |
| Occupational and/or physiotherapy | Motor or sensory concerns | Motor and/or sensory assessment |
| Behaviour therapy | Behavioural concerns | Behavioural assessment |
Note: EEG = electroencephalogram, HbA1c = glycated hemoglobin, SD = standard deviation of the mean, T4 = tetraiodothyronine, TSH = thyroid stimulating hormone.
↵* This list does not imply uniform practice.
↵† Consider adding magnetic resonance spectroscopy if there is regression or other clinical indicators of metabolic disease.
↵‡ May not be needed at the time of diagnosis, but may be required later to ensure appropriate academic supports.