Pediatrics · Year 3 · from Pediatrics
Case 3: Global Developmental Delay
Patient Demographics
- Age: 18-month-old female
- Sex: Female
Chief Complaint
"She's not walking or talking like her older brother did."
History of Present Illness
An 18-month-old girl is brought to her pediatrician because her parents are concerned about her development. She is not yet walking independently and only pulls to stand with support. She has no words and babbles infrequently. She does not point or wave bye-bye. She can pick up small objects but has difficulty with a pincer grasp. Her parents note she is less interactive than her brother was at this age. She was born full-term without complications. There is no family history of developmental delays. She has had recurrent ear infections and is scheduled for myringotomy tubes.
Developmental Assessment (Ages and Stages Questionnaire at 18 months)
| Domain | Score | Status |
|---|---|---|
| Gross Motor | 20 | Below cutoff |
| Fine Motor | 30 | Below cutoff |
| Communication | 15 | Below cutoff |
| Problem-solving | 25 | Below cutoff |
| Personal-social | 30 | At cutoff |
Physical Examination
- Vital Signs: Weight 25th percentile, Length 30th percentile, Head circumference 15th percentile
- General: Quiet infant, makes some eye contact
- HEENT: Bilateral middle ear effusions
- Cardiovascular: Normal
- Neurologic: Mild central hypotonia; pulls to stand with support, not walking; age-appropriate reflexes
Additional Workup
- Audiology: Moderate conductive hearing loss bilaterally (consistent with chronic effusions)
- Thyroid function: TSH 5.2 mIU/L (normal)
- Lead level: 2 mcg/dL (normal)
- Chromosomal microarray: Pending
Diagnosis
Global developmental delay (delays in 2 or more domains in a child under 5 years)
Clinical Reasoning
This child has significant delays in multiple developmental domains (gross motor, fine motor, language, cognitive), meeting criteria for global developmental delay. While her hearing loss likely contributes to language delay, it does not explain delays in motor and cognitive domains. The combination of microcephaly (head circumference 15th percentile with height/weight higher), hypotonia, and global delays suggests an underlying etiology that should be investigated. The differential includes genetic conditions (chromosomal abnormalities, single gene disorders), metabolic disorders, and structural brain abnormalities. The distinction between "developmental delay" (used in children under 5) and "intellectual disability" (requires formal cognitive testing, usually after age 5) is important.
Management
- Early intervention referral (Part C): Immediate referral for comprehensive developmental services
- Audiology treatment: Proceed with myringotomy tubes; reassess hearing after
- Genetic testing:
- Chromosomal microarray (first-line for unexplained developmental delay)
- Fragile X testing
- Additional genetic testing based on microarray results
- Brain MRI: Evaluate for structural abnormalities given microcephaly
- Metabolic screening: Consider if MRI and genetic testing unrevealing
- Therapy services:
- Physical therapy for gross motor delays
- Occupational therapy for fine motor delays
- Speech-language therapy for communication
- Close follow-up: Serial developmental assessments to monitor progress
- Family support: Genetic counseling, parent support groups
Clinical Image
Image Description: Developmental milestone chart comparing expected milestone acquisition ages with delayed patterns, illustrating the concept of global developmental delay affecting multiple domains simultaneously.
Source: Wikimedia Commons - CDC Milestones URL: https://commons.wikimedia.org/wiki/File:Developmental_milestones.svg License: Public Domain