Differential Diagnosis for Conditions with a Flat Undefined Cupid's Bow, Small Mouth, and Neuropsychiatric Symptoms

• Single Most Likely Diagnosis
  • Fetal Alcohol Syndrome (FAS): This condition is characterized by a flat, undefined Cupid's bow, small mouth, and various neuropsychiatric symptoms due to prenatal alcohol exposure. The facial features, combined with developmental and cognitive impairments, make FAS a leading consideration.
• Other Likely Diagnoses
  • Williams Syndrome: Although more commonly associated with a friendly demeanor and distinctive "elfin" facial features, some individuals with Williams Syndrome may present with a less defined Cupid's bow and small mouth, alongside neuropsychiatric symptoms such as anxiety and attention deficits.
  • Smith-Magenis Syndrome: Characterized by a flat face, small mouth, and neuropsychiatric symptoms including attention deficit hyperactivity disorder (ADHD), anxiety, and sleep disturbances, making it a plausible diagnosis.
• Do Not Miss Diagnoses
  • Foetal Valproate Syndrome: Exposure to valproate during pregnancy can lead to a range of developmental and physical abnormalities, including facial dysmorphia and neuropsychiatric issues. Given the potential severity of outcomes, it's crucial not to miss this diagnosis.
  • Congenital Hypothyroidism: While not primarily associated with a flat Cupid's bow and small mouth, untreated congenital hypothyroidism can lead to developmental delays and neuropsychiatric symptoms. Early diagnosis is critical for effective management.
• Rare Diagnoses
  • Brachmann-de Lange Syndrome: A rare genetic disorder characterized by distinctive facial features (which can include a small mouth), developmental delays, and various neuropsychiatric symptoms. The rarity of this condition, combined with its severe manifestations, warrants consideration in a differential diagnosis.
  • Kabuki Syndrome: Another rare condition with facial dysmorphia (including a flat face and small mouth in some cases) and a range of neuropsychiatric symptoms. Its rarity and the importance of early intervention for optimal outcomes place it in the rare but significant category.