What tests and evaluations should be ordered for further assessment?

Appropriate Diagnostic Tests for Further Evaluation

For comprehensive evaluation, order a complete metabolic panel, CBC with differential, thyroid function tests, vitamin B12 and folate levels, and appropriate imaging based on clinical presentation.

Initial Laboratory Testing

• Complete metabolic panel (CMP) should be ordered as part of the basic medical evaluation to assess for metabolic disorders, liver function, and kidney function 1
• Complete blood count (CBC) with differential to evaluate for anemia, infection, or other hematologic abnormalities 1
• Thyroid function tests to rule out thyroid dysfunction, particularly hypothyroidism which can present with cognitive changes 1
• Vitamin B12 and folate measurements to assess for deficiencies that may impact neurological function 1
• Serum tryptase levels and vitamin B12 levels if eosinophilia is present to evaluate for myeloproliferative disorders 1

Imaging Studies

• Neuroimaging (CT or MRI) should be considered when there are focal neurological findings, evidence of neurological dysfunction, or clinical suspicion of structural abnormalities 1
• Electrocardiogram (ECG) if cardiovascular symptoms are present or if there is suspicion of cardiac involvement 1
• Echocardiography if there are signs or symptoms suggestive of cardiac disease 1

Specialized Testing Based on Clinical Presentation

For Neurodevelopmental Concerns:

• Chromosomal microarray (CMA) as a first-tier test for patients with unexplained developmental delay, intellectual disability, or autism spectrum disorder 1
• Fragile X testing, particularly for males with developmental concerns 1
• MECP2 sequencing for females with developmental concerns 1
• Consider metabolic and/or mitochondrial testing if there are suggestive clinical indicators 1

For Hematologic Abnormalities:

• If eosinophilia is present, consider bone marrow aspirate and biopsy with immunohistochemistry, cytogenetics, FISH, and/or RT-PCR to detect TK fusion gene rearrangements 1
• Serology testing for parasitic infections if eosinophilia is present 1

For Gastrointestinal Symptoms:

• Stool studies including ova and parasites, occult blood, and gastrointestinal PCR if diarrhea is present 1
• Celiac serology if there are symptoms suggestive of malabsorption 1
• Fecal calprotectin if inflammatory bowel disease is suspected (particularly in patients <45 years with diarrhea) 1

For Urologic Concerns:

• Urinalysis to evaluate for hematuria, pyuria, or other abnormalities 1
• If urinary symptoms are present, consider urodynamic studies or cystoscopy 1

Follow-up Testing

• For abnormal initial findings, follow-up with targeted testing based on specific abnormalities 1
• Consider referral to appropriate specialists (neurology, hematology, gastroenterology) based on abnormal findings 1
• For patients with suspected cognitive decline, consider neuropsychological testing 1

Important Considerations

• The extensiveness of the workup should be guided by clinical presentation, age, and risk factors 1, 2
• Laboratory testing should be justified based on the clinical presentation and significant findings in the history or physical examination 1
• Avoid unnecessary testing when there is low pre-test probability of abnormal findings 3
• Consider cost-effectiveness when ordering panels; in some cases, targeted testing may be more appropriate than comprehensive panels 3