Clinical Guidance

The mitochondrial membrane protein encoded by CPT1A enables oxidation of long-chain fatty acyl-coenzyme A molecules in the liver to provide an alternative source of energy when liver glycogen reserves have been significantly reduced, most often during fasting or intercurrent illness . This pathway fuels ketogenesis for metabolism in other tissues that cannot oxidize fatty acids. Thus, clinical manifestations of CPT1A deficiency usually occur with a febrile or gastrointestinal illness when energy demands are increased. Although the precipitating illness may be a relatively common infectious disease, onset of manifestations is usually rapid. Age of onset of manifestations can vary from the newborn period to adulthood, and some individuals are asymptomatic.

Diagnostic Criteria

No consensus clinical diagnostic criteria for carnitine palmitoyltransferase 1A (CPT1A) deficiency have been published.

Suggestive Findings

Source: GeneReviews — "Carnitine Palmitoyltransferase 1A Deficiency"

Management Guidelines

No clinical practice guidelines for carnitine palmitoyltransferase 1A (CPT1A) deficiency have been published. In the absence of published consensus guidelines, the following recommendations are based on available evidence and literature on the subject. When CPT1A deficiency is suspected during the diagnostic evaluation (for example, because of a suggestive carnitine and acylcarnitine profile; see ), metabolic treatment including fasting precautions should be initiated immediately. Development and evaluation of treatment plans, training and education of affected individuals and their families, and avoidance of side effects of dietary treatment (e.g., malnutrition, growth failure) require a multidisciplinary approach including multiple subspecialists, with oversight and expertise from a specialized metabolic center. Guidelines and current management strategies for the treatment of CPT1A deficiency and other long-chain fatty acid oxidation disorders can be found at www.newbornscreening.info and (full text). The British Inherited Metabolic Disease Group (BIMDG) website has a specific emergency management protocol for CPT1A deficiency (see Emergency Guides - BIMDG).

Surveillance Guidelines

Table 7. Carnitine Palmitoyltransferase 1A Deficiency: Recommended Surveillance