Neurologic outcome of propionic acidemia

Area of Science:

• Biochemistry
• Genetics
• Neurology

Background:

• Propionic acidemia is an inherited metabolic disorder affecting amino acid metabolism.
• The clinical presentation and outcomes can vary significantly based on disease onset.

Purpose of the Study:

• To retrospectively analyze the clinical course and outcomes of propionic acidemia patients.
• To compare outcomes between early-onset (first week of life) and late-onset (after neonatal period) propionic acidemia.

Main Methods:

• Retrospective review of 20 patients diagnosed with propionic acidemia.
• Patients were categorized into two groups based on age at presentation: early-onset and late-onset.
• Clinical data, including mortality, neurological status (IQ), movement disorders, and neuroimaging, were analyzed.

Main Results:

• Early-onset propionic acidemia (11 patients) had a significantly higher death rate (hazard ratio: 7.52) compared to late-onset (9 patients).
• All patients in the early-onset group exhibited intellectual disability (IQ ≤ 60).
• Movement disorders were prevalent in both groups; severe movement disorders were more common in the late-onset group, associated with transient basal ganglia lucencies on CT scans, but normal cerebrospinal fluid amine neurotransmitter metabolites.

Conclusions:

• Early-onset propionic acidemia is associated with severe outcomes, including high mortality and intellectual disability.
• Late-onset propionic acidemia can manifest with significant movement disorders and transient neuroimaging abnormalities.
• Neurotransmitter metabolite levels in CSF do not appear to be disturbed in late-onset propionic acidemia following metabolic decompensation.