[Diagnosis and follow up of 23 children with organic acidurias].

Background: Propionic aciduria (PA) and Methymalonic aciduria (MMA) result from an inherited abnormality of the enzymes propionyl CoA carboxylase and methylmalonyl CoA mutase respectively. This produces marked increases in the amino acids methionine, threonine, valine and isoleucine (MTVI). Their clinical presentation can be neonatal or late onset forms.

Aim: To report 23 children with organic acidurias.

Material And Methods: Twenty three cases of organic acidurias diagnosed since 1980 (17 PA and 6 MMA) and followed at the Institute of Nutrition and Food Technology, are reported.

Results: The average age of diagnosis was 3.9 days for the neonatal form and 8.3 months for the late onset form. The most frequent symptoms were hypotonia, lethargy and vomiting. Neonatal PA had mean ammonemias of 1089 +/- 678.3 micrograms/dl. The figure for MMA was 933 +/- 801.9 micrograms/dl. Seven children were dialyzed and 30% died. 16 children are followed and 81.2% have normal weight for age. Seven children required gastrostomy because of anorexia and failure to thrive. The nutritional treatment is based on natural and artificial proteins without MTVI, with periodical controls, amino acid and ammonia quantification. Some patients were submitted to enzyme assays and molecular studies.

Conclusions: An early diagnosis and a very strict follow up allows a normal development of children with organic acidurias. There is a relationship between prognosis and the presentation form, the nutritional status and the emergency treatment during acute episodes. The importance of the enzymatic and molecular studies is emphasized because they facilitate treatment, accurate diagnosis and allow an adequate genetic counseling.