Table 6a.

Classic Isovaleric Acidemia: Routine Daily Treatment

Principle/ManifestationTreatmentConsiderations/Other
General Intense & ongoing education of affected persons & caregivers re natural history, maintenance & emergency treatment, prognosis, & risks of acute encephalopathic crises
Nutrition /
Dietary management 		Low-leucine diet in infants (See Targeted Therapy.)
After being given prescribed quantities of leucine-free formula, infants can breastfeed on demand.
  • Breastfeeding should be encouraged.
  • Leucine content in breast milk is 130 mg per 100 mL.
  • Daily leucine intake can be calculated when breast milk is the only natural protein source & breast milk intake is calculated & stable.
  • Protein-controlled diet in adolescents & adults to avoid excess protein
  • Adequate supplies of specialized dietary products should always be maintained at home.
After school age the dietary mgmt is usually relaxed. With increasing age, the risk of acute metabolic decompensations declines. Metabolic decompensations are usually not present after adolescence (except for a few reported instances). The natural protein intake can be adjusted to the WHO/FAO/UNU safe levels of protein to avoid protein malnutrition.
Acute metabolic decompensation
  • Treatment protocols & provision of emergency letters or cards to include guidance for care in the event of illness while on holiday/vacation
  • MedicAlert® bracelets/pendants or car seat stickers
  • Written protocols for maintenance & emergency treatment should be provided to parents, primary care providers / pediatricians, teachers, & school staff. 1, 2
  • Emergency letters/cards should be provided summarizing key information & principles of emergency treatment for classic IVA & containing contact information for primary treating metabolic center.
  • For any planned travel or vacations, consider contacting a center of expertise near the destination prior to travel dates.
Movement disorders Referral to neurologist for ongoing mgmt
Gross motor delay
  • Physical therapy
  • Aggressive rehab therapy
Surgery or procedure (including dental procedures)
  • Notify designated metabolic center in advance of procedure to discuss perioperative mgmt w/surgeons & anesthesiologists.
  • Emergency surgeries/procedures require planning input from physicians w/expertise in inherited metabolic diseases (w/respect to perioperative fluid & nutritional mgmt).
Consider placing a "flag" in the affected person's medical record such that all care providers are aware of the diagnosis & the need to solicit opinions & guidance from designated metabolic specialists in the setting of certain procedures.

IVA = isovaleric acidemia; WHO/FAO/UNU = World Health Organization / Food and Agriculture Organization of the United Nations / United Nations University

1.

Essential information including written treatment protocols should be provided before inpatient emergency treatment might be necessary.

2.

Parents or local hospitals should immediately inform the designated metabolic center if: (1) temperature rises >38.5 °C; (2) vomiting/diarrhea or other symptoms of intercurrent illness develop; or (3) new neurologic manifestations occur.

From: Classic Isovaleric Acidemia

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