Classification and goals - IVA

Basically three clinical forms of IVA are known:
Acute neonatal presentation	After a normal pregnancy and birth, neonates become symptomatic within the first two weeks of life, developing vomiting and lethargy, progressing into coma.
Intermittend presentation	The late onset form of IVA presents after a longer symptom-free period of at least a year or longer. Patients present relatively non-specific failure to thrive and/or developmental delay, evolving into more severe periods of ketoacidosis with coma or lethargy during times of catabolism.
asymptomatic presentation	An increasing number of patients with a mild phenotype are diagnosed through New Born Screening (NBS)

The management of IVA consists of :

Dietary restriction of leucine, by means of a protein (moderate) restriction, while ensuring adequate safe level in protein intake. The use of Leucine free L-amino acids supplements is not standard care and usually only in the infants/young patients ageranges.
Adjunct therapy, such as L-carnitine and co-factors supplementation,
Supplementation of vitamins, minerals and trace elements depends on the strictness of the diet
Avoid or management of catabolism to prevent metabolic decompensation and ensuring optimal growth and development by providing adequate energy intake
Glycine and carnitine supplementation to increase excretion of isovaleric acid, which can influence the strictness of the metabolic diet.

Dixon M, Macdonald A, White F. Disorders of amino acid metabolism, organic acidaemias and Urea cycle disorders. In; Shaw V (ed) Clinical paediatric dietetics, 4^th John Wiley & Sons ltd. Sussex, 2015:381-526
Knerr I, Vockley J, Gibson KM. Disorders of leucine, isoleucine and valine metabolism. In; Blau N (ed) Physician’s guide to the diagnosis, treatment and follow-up of inherited metabolic diseases, 2^nd Springer Heidelberg, 2014103-142
Marriage B. Nutrtional management of patients with inherited disorders of brached-chain amino acid metabolism. In: Acosta PB (ed) Nutritional management of patients with inherited metabolic disorders, 1^st Jones and Bartlett, Sudbury 2010:175-236
Knerr I, Vockley J, Gibson KM. Disorders of leucine, isoleucine and valine metabolism. In; Blau N (ed) Physician’s guide to the diagnosis, treatment and follow-up of inherited metabolic diseases, 2^nd Springer Heidelberg, 2014103-142