Differential Diagnosis
- Single most likely diagnosis: + E. Trinucleotide repeat expansion on chromosome 4p: This is the most likely diagnosis, as it is associated with Huntington's disease, which is characterized by chorea, a condition that affects movement. The trinucleotide repeat expansion on chromosome 4p is a specific genetic mutation that leads to this disease.
- Other Likely diagnoses: + A. Autoimmune injury to basal ganglia: This could be a possible diagnosis, as autoimmune disorders can affect the basal ganglia, leading to movement disorders. However, it is less likely than the trinucleotide repeat expansion. + B. Bilirubin-induced neurotoxicity: This is a possible diagnosis, especially in infants with high bilirubin levels, which can cause kernicterus and lead to movement disorders.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.): + B. Bilirubin-induced neurotoxicity: Although it may not be the most likely diagnosis, bilirubin-induced neurotoxicity can be deadly if missed, especially in infants. Prompt treatment is necessary to prevent long-term damage.
- Rare diagnoses: + C. MECP2 gene mutation: This is a rare diagnosis, associated with Rett syndrome, which is a genetic disorder that affects brain development and is characterized by intellectual disability and movement disorders. + D. Physiologic chorea of infancy: This is a rare and benign condition that affects infants, characterized by involuntary movements. It is usually self-limiting and resolves on its own.