Medical tests for children with Autism

Autism spectrum disorder may be associated with certain genetic syndromes or medical conditions.  Recently we are getting more success in finding the underlying cause for autism.  The battery of laboratory tests  that I request may depend on the child’s history and physical examination. Following are some of the tests that I consider when children are diagnosed with autism.

Chromosomal Microarray:

It is a simple blood test.  This test is very sensitive and up to 10-20% of children with autism can show abnormalities recognized through this testing.genetic testing becomes even more important if the child has short stature on some recognizable physical abnormalities such as unusual facial features, unusual dentition, or abnormal palmar creases.  Any family history of genetic disorder or intellectual disability may also increase the chance that this test may show underlying genetic abnormality.  Fragile X syndrome is diagnosed in up to 2% of boys diagnosed with ASD. Further information about CMA is available here.

Lead levels:

I screen some children for lead toxicity if they live in high risk environment such as  very old buildings or if they have pica ( a condition in which children eat non-edible stuff such as sand, paper).

Iron levels:

If children’s are picky eater or if they drink milk over 20 ounces per day I like to include either levels also.  Iron deficiency can cause sleep and behavior problem besides causing fatigue.  It can further impair developmental delays.


Children with ASD have many stereotypical movements. Many children may like to stare at light, fan or wheels in an unusual way that may sometimes raises the question about atypical seizures. If the child has staring spells or unusual movements I requested EEG.

Vitamin D levels:

Alberta health services in Calgary no longer accepts the lab request for vitamin D levels.  Vitamin D levels are done  for very specific  medical reasons.  So instead I routinely recommend starting children on vitamin D 400-800 international units daily.

Other Tests:

I also like to screen children for thyroid abnormalities most importantly hypothyroidism.  Children who have less active thyroid may become constipated, tired and may have sleep abnormalities. Measurement of trace metals such as Mercury, Stool analysis, Study of micro-nutrients or multivitamin or Hair analysis are not recommended because of lack of clinical evidence.  Except  the measurement of certain trace metals, these studies are not done at Alberta health services lab in Calgary.  Most of these tests are done at specialized labs usually located in USA.  These tests  can be expensive.