Differential Diagnosis for Global Developmental Delay in a 1-Year-Old Girl

Single Most Likely Diagnosis

• Cerebral Palsy: This condition is a leading cause of global developmental delay in children, characterized by impaired movement, muscle tone, or posture. The diagnosis is often made clinically, based on the child's physical examination and developmental history.

Other Likely Diagnoses

• Genetic Disorders (e.g., Down Syndrome, Fragile X Syndrome): These conditions can cause developmental delays and often have distinctive physical features or behavioral patterns.
• Neurodevelopmental Disorders (e.g., Autism Spectrum Disorder): While primarily affecting social interaction and communication, these disorders can also impact cognitive and motor development.
• Infections (e.g., Congenital Infections like CMV or Toxoplasmosis): Certain infections acquired in utero can lead to developmental delays.
• Nutritional Deficiencies (e.g., Vitamin D Deficiency): Severe deficiencies, especially in critical developmental periods, can impact growth and development.

Do Not Miss Diagnoses

• Hypothyroidism: Untreated congenital hypothyroidism can lead to severe developmental delays and intellectual disability. Early detection and treatment are crucial.
• Phenylketonuria (PKU): This metabolic disorder, if left untreated, can cause intellectual disability and other serious health problems.
• Tuberous Sclerosis Complex: A genetic disorder that can cause developmental delay, seizures, and tumors in various organs.
• Lead Poisoning: Exposure to lead, even at low levels, can cause developmental delays, among other health issues.

Rare Diagnoses

• Mitochondrial Disorders: A group of disorders caused by dysfunctional mitochondria, affecting energy production in cells, which can lead to developmental delays among other symptoms.
• Kabuki Syndrome: A rare genetic disorder characterized by distinctive facial features, growth delays, and developmental delays.
• Rett Syndrome: A genetic disorder that almost exclusively affects girls, causing severe developmental delays, especially impacting hand use and spoken language.
• Angelman Syndrome: Characterized by developmental delays, intellectual disability, severe speech impairment, and microcephaly, often with a happy demeanor.

Each of these diagnoses requires a thorough medical evaluation, including a detailed history, physical examination, and often, specific diagnostic tests to confirm the diagnosis and guide treatment. The treatment protocol will vary significantly depending on the underlying cause of the global developmental delay.