Propionic acidemia

Propionic acidemia is an autosomal recessive disorder in which the body is unable to process certain parts of proteins and lipids. It is classified as an organic acid disorder (organic acids build up).


Diagnosis:


Symptoms appear within a few days of birth and include vomiting, poor feeding, hypotonia and lethargy. Leukocyte propionyl CoA carboxylase activity is the study required for definitive biochemical diagnosis and appropriate genetic counseling. Blood ammonia levels (elevated secondarily), Lactate levels, electrolytes, Urine ketones are other tests recommended in this condition. Anion gap will be increased due to increased unmeasured acids. ECG is recommended in all patients because of increased risk of prolonged QTc interval.


Pathophysiology:


The enzyme propionyl-CoA carboxylase is dysfunctional in propionic acidemia. Mutations in the PCCA and PCCB genes are responsible. As a result propionyl CoA accumulates in the body.


Treatment:


In acute illness - extra calories. No proteins. Once clinical condition improves can resume proteins at a very low concentration using special formulas that lack in isoleucine, valine, threonine, methionine