What are the common features and management strategies for Down syndrome?

Common Features and Management Strategies for Down Syndrome

Down syndrome is characterized by distinctive physical features including upslanting palpebral fissures, epicanthal folds, flat nasal bridge, Brushfield spots of the iris, shortened incurving fifth finger, and transverse palmar crease, with hypotonia present in virtually all individuals. 1

Physical Features and Manifestations

Craniofacial Features

• Flat occiput
• Upslanting palpebral fissures
• Epicanthal folds
• Brushfield spots (speckled iris)
• Flat nasal bridge
• Protruding tongue
• Macroglossia
• Prominent or malformed ears 1, 2

Musculoskeletal Features

• Hypotonia (present in virtually all individuals)
• Shortened, incurving fifth finger
• Transverse palmar crease
• Cervical spine instability (requires assessment before anesthesia) 1, 2

Cardiovascular System

• Congenital heart disease in 40% of cases, including:
  • Atrioventricular septal defects
  • Ventricular septal defects
  • Atrial septal defects
  • Patent ductus arteriosus
  • Tetralogy of Fallot 1

Respiratory System

• Obstructive sleep apnea (highly prevalent)
• Upper and lower airway issues:
  • Macroglossia
  • Adenotonsillar hypertrophy
  • Laryngomalacia
  • Smaller/narrow trachea
  • Tracheo- and bronchomalacia
  • Decreased number of alveoli (up to 25%)
  • Impaired mucociliary clearance 1

Gastrointestinal System

• Gastrointestinal anomalies in 5% of cases:
  • Duodenal atresia
  • Hirschsprung disease 1

Sensory Systems

• Hearing loss (congenital temporal bone anomalies, external auditory canal stenosis)
• Recurrent otitis media
• Visual impairments 2

Neurodevelopmental and Psychiatric Features

Cognitive Development

• Intellectual disability (typically mild to moderate)
• Intelligence Quotient typically in the range of 35-70 1, 3
• Developmental delays in multiple domains:
  • Motor skills (typically takes twice as long as typical children)
  • Adaptive functioning
  • Feeding
  • Toilet training
  • Sleep patterns
  • Social development 1

Language and Communication

• Speech delay
• Poor articulation related to narrow oral cavity
• Difficulties in language comprehension
• Receptive language typically stronger than expressive language
• Particular challenges in phonology and syntax 3, 4

Psychiatric and Behavioral Features

• Neurobehavioral and psychiatric comorbidities in 18-38% of individuals
• Common issues include:
  • Heightened motor activity and impulsivity
  • Noncompliance or tantrums
  • Restlessness and anxiety
  • Disruptive behavior
  • Repetitive movements
  • Distinctive patterns of sensory responsiveness 1
• Approximately 7% exhibit signs of autism by age 2-3 years 1

Neurological Concerns

• Seizures (more frequent than in general population)
• Alzheimer's disease neuropathology (present in nearly 100% of individuals by age 40)
• Clinical Alzheimer's disease in at least 50% of adults aged 60 and older 1

Management Strategies

Medical Management

1. Cardiovascular Management:

   • Echocardiogram at diagnosis
   • Regular cardiac follow-up for those with congenital heart defects
   • Endocarditis prophylaxis for high-risk patients 1

2. Respiratory Management:

   • Sleep studies to assess for obstructive sleep apnea
   • Noninvasive ventilation (CPAP or BiPAP) for sleep apnea
   • Consider high-flow nasal cannula as an alternative for those with poor adherence
   • Special consideration during intubation (use endotracheal tube two sizes smaller than standard) 1, 2

3. Hearing and Vision:

   • Hearing assessment in neonatal period with appropriate follow-up
   • Aggressive treatment of conductive hearing loss
   • Early amplification when necessary
   • Regular ophthalmologic evaluations 2

4. Growth and Endocrine:

   • Regular growth monitoring using Down syndrome-specific growth charts
   • Thyroid function tests (increased risk of thyroid disorders)

Neurodevelopmental Management

1. Early Intervention:

   • Speech and language therapy (focus on both receptive and expressive language)
   • Physical therapy for hypotonia and motor delays
   • Occupational therapy for fine motor and adaptive skills
   • Special education services with individualized education plans 3

2. Cognitive and Behavioral Support:

   • Behavioral therapy for challenging behaviors
   • Structured routines and visual supports
   • Tailored educational approaches that capitalize on visual learning strengths 3

3. Alzheimer's Disease Monitoring:

   • Baseline cognitive assessment by age 40
   • Regular monitoring for cognitive decline
   • Thorough medical evaluation for any changes in function to rule out treatable conditions 1

Family Support and Education

• Genetic counseling for families
• Connection to support groups and resources
• Education about expected developmental trajectory
• Guidance on transition planning for adolescents and adults

Screening Recommendations

• Cardiac evaluation at birth
• Hearing assessment in neonatal period
• Thyroid function tests at birth and regularly thereafter
• Vision screening
• Cervical spine radiographs to assess for atlantoaxial instability
• Sleep studies to evaluate for obstructive sleep apnea
• Regular developmental assessments

By implementing comprehensive and coordinated care across multiple specialties, individuals with Down syndrome can achieve improved health outcomes and quality of life throughout their lifespan, with many individuals without congenital heart disease now living beyond 60 years of age 1.