Can you provide a comprehensive clerking template for assessing a patient with autism spectrum disorder (ASD)?

Autism Spectrum Disorder Clerking Template

Use the structured tiered evaluation approach from the 2013 ACMG guidelines, which provides a systematic framework for assessing patients with ASD from initial presentation through genetic evaluation and counseling. 1

Pre-Evaluation Requirements

Before initiating the genetic evaluation, confirm the following:

• Formal ASD diagnosis by a trained professional using objective criteria and standardized tools 2
• Complete audiogram to rule out significant hearing loss (mandatory for all patients) 1, 2
• Cognitive testing to establish baseline intellectual functioning 2
• Verify newborn screening results 2
• EEG if clinical suspicion of seizures exists 2
• High-resolution chromosomal analysis and Fragile X studies may be performed before referral 2

History Taking

Developmental History

• Age of symptom onset and pattern of development
• Regression history (warrants additional metabolic/genetic workup) 3
• Milestone achievement in social, communication, motor, and cognitive domains
• Pattern of restricted interests and repetitive behaviors

Family History

• Recurrence risk counseling: 3-10% for full siblings (7% if affected child is female, 4% if male; ≥30% if two or more affected children) 1
• Family history of ASD, intellectual disability, psychiatric conditions
• Consanguinity
• Three-generation pedigree

Medical History

• Prenatal exposures (infections, medications, alcohol, toxins)
• Birth history and perinatal complications
• Infectious history: encephalitis, meningitis, congenital rubella 3
• Seizure history or staring spells 3
• Head trauma 3
• Endocrine disorders (hypothyroidism) 3

Current Functioning

• Communication abilities (receptive and expressive language, pragmatic skills)
• Adaptive functioning across domains
• Sleep patterns and disturbances
• Sensory sensitivities or motor difficulties
• Behavioral challenges and their functional impact

Physical Examination

Dysmorphology Assessment

Critical first step: Detailed examination for dysmorphic features to identify syndromic forms of ASD 2

• Growth parameters: Height, weight, head circumference (plot on growth charts)
  • Head circumference >2.5 SD above mean triggers PTEN gene testing 2
• Facial features (eyes, ears, nose, mouth, philtrum)
• Limb abnormalities
• Skin examination with Woods lamp evaluation (mandatory to detect hypopigmented macules suggesting tuberous sclerosis) 2
• Clonal pigmentary abnormalities (triggers fibroblast karyotype if leukocyte karyotype normal) 2
• Neurological examination

First-Tier Genetic/Metabolic Testing

Proceed with these investigations if not already performed:

Mandatory for All Patients

• High-resolution chromosomal analysis (peripheral karyotype) 2
• Fragile X DNA testing 2

If Clinical Indicators Present

• Rubella titers (if clinical indicators suggest congenital infection) 2
• Metabolic screening (only if clinical indicators present AND condition not assessed by newborn screening): 2
  • Urine mucopolysaccharides and organic acids
  • Serum lactate, amino acids, ammonia, acyl-carnitine profile

If Specific Syndrome Suspected

Proceed directly with targeted testing for that condition 2

Second-Tier Testing

Order based on first-tier results and clinical findings:

• Chromosomal microarray (comparative genomic hybridization) - now elevated to near first-tier status given 30-40% diagnostic yield 1, 2
• Fibroblast karyotype if leukocyte karyotype normal AND clonal pigmentary abnormalities noted 2
• MECP2 gene testing (females only) 2
• PTEN gene testing if head circumference >2.5 SD above mean 2

Third-Tier Testing

Consider based on clinical suspicion:

• Brain MRI 2
• Serum and urine uric acid: 2
  • If elevated: HgPRT and PRPP synthetase superactivity testing
  • If low: purine/pyrimidine panel (uracil excretion, xanthine, hypoxanthine)

Tests NOT Recommended for Routine Use

The following lack sufficient evidence for routine testing 1:

• CDKL5 testing
• Cholesterol/7-dehydrocholesterol
• Chromosome 15 methylation/UBE3A gene testing
• Mitochondrial gene sequencing
• Selected neurometabolic screening (unless specific clinical indicators present)

Assessment of Co-occurring Conditions

Psychological Assessment

• Standardized intelligence testing (note scatter and splinter/savant skills) 3
• Adaptive behavior measures 3
• Areas of strength and weakness for intervention planning 3

Communication Assessment

• Receptive and expressive vocabulary 3
• Pragmatic/social language use 3

Additional Evaluations as Indicated

• Occupational therapy for sensory/motor difficulties 3
• Physical therapy evaluation 3
• Sleep assessment 3

Coordination and Follow-Up

• Establish primary care medical home for every patient 1
• Partner between primary care physician and clinical geneticist for test coordination 1
• Periodic reevaluations for patients without initial etiologic diagnosis (timing negotiated among patient/family, primary care, and geneticist) 1
• Changes in technology and phenotype understanding may aid later diagnosis 1

Genetic Counseling

Provide to all families regardless of whether etiology identified:

If Etiology Identified

• Specific recurrence risks based on identified condition
• Natural history and prognosis
• Management implications
• Available treatments

If No Etiology Identified

• Use empiric recurrence risk data (3-10% for siblings, modified by sex as above) 1
• Discuss possibility of future testing as technology advances 1

Key Clinical Pitfalls to Avoid

• Do not skip the audiogram - hearing loss must be ruled out before attributing symptoms to ASD 1, 2
• Do not order extensive metabolic panels without clinical indicators - this is poorly tolerated by families and not cost-effective 2
• Do not miss the Woods lamp examination - tuberous sclerosis can be easily overlooked 2
• Do not forget to measure head circumference accurately - macrocephaly triggers specific genetic testing 2
• Do not delay referral to genetics - diagnostic yield is now 30-40% with modern testing 1