Sorted By Test Name - Mayo Medical Laboratories

CPTKM
61121
CARN
8802
screening can be done with plasma acylcarnitines. Definitive diagnosis can be made by detection of
reduced CPT enzyme activity. Mutations in the CPT2 gene are responsible for CPT II deficiency and
sequencing of this gene is recommended after positive biochemical analysis.
Useful For: Confirmation of diagnosis of carnitine palmitoyltransferase II deficiency Carrier screening
in cases where there is a family history of carnitine palmitoyltransferase II deficiency, but disease-causing
mutations have not been identified in an affected individual
Interpretation: An interpretative report will be provided.
Reference Values:
An interpretive report will be provided.
Clinical References: 1. Bonnefont JP, Djouadi F, Prip-Buus C, et al: Carnitine palmitoyltransferases
1 and 2: biochemical, molecular and medical aspects. Mol Aspects Med 2004 Oct-Dec;25(5-6):495-520 2.
Siguake E, Rakheja D, Kitson K, Bennet M: Carnitine palmitoyltransferase II deficiency: a clinical,
biochemical, and molecular review. Lab Invest 2003 Nov;83(11):1543-1554
Carnitine Palmitoyltransferase II Deficiency, Known Mutation
Clinical Information: Carnitine palmitoyltransferase II (CPT II) deficiency is an autosomal recessive
disorder of long-chain fatty-acid oxidation. There are 3 distinct clinical phenotypes: a lethal neonatal
form, an early-onset infantile form, and a late-onset adult myopathic form. The lethal neonatal and
early-onset infantile forms are characterized by liver failure, cardiomyopathy, seizures, hypoketotic
hypoglycemia, peripheral myopathy, and early death. The adult-onset myopathic form is the most
common type and is characterized by exercise-induced muscle pain and weakness and may be associated
with myoglobinuria. Males are more likely to be affected with the myopathic form than females. Initial
screening can be done with plasma acylcarnitines. Definitive diagnosis can be made by detection of
reduced CPT enzyme activity. Mutations in the CPT2 gene are responsible for CPT II deficiency and
sequencing of this gene is recommended after positive biochemical analysis.
Useful For: Diagnostic confirmation of carnitine palmitoyltransferase II deficiency when familial
mutations have been previously identified Carrier screening of at-risk individuals when a mutation in the
CPT2 gene has been identified in an affected family member
Interpretation: An interpretative report will be provided.
Reference Values:
An interpretive report will be provided.
Clinical References: 1. Bonnefont JP, Djouadi F, Prip-Buus C, et al: Carnitine palmitoyltransferases
1 and 2: biochemical, molecular and medical aspects. Mol Aspects Med 2004 Oct-Dec;25(5-6):495-520 2.
Siguake E, Rakheja D, Kitson K, Bennet M: Carnitine palmitoyltransferase II deficiency: a clinical,
biochemical, and molecular review. Lab Invest 2003 Nov;83(11):1543-1554
Carnitine, Plasma
Clinical Information: Carnitine and its esters are required for normal energy metabolism and serve 4
primary functions: -Importing long-chain fatty acids into the mitochondria -Exporting naturally-occurring
short-chain acyl-CoA groups from the mitochondria -Buffering the ratio of free CoA to esterified CoA
-Removing potentially toxic acyl-CoA groups from the cells and tissues Evaluation of carnitine in plasma,
tissue, and urine is a screening test for patients suspected of having primary disorders of the carnitine
cycle, or secondary disturbances in carnitine levels as a result of organic acidemias and fatty acid
oxidation disorders. In the latter disorders, acyl-CoA groups accumulate and are excreted into the urine
and bile as carnitine derivatives, resulting in a secondary carnitine deficiency. More than 100 such
primary and secondary disorders have been described. Individually, the incidence of these disorders varies
from 1:1,000,000 live births. Collectively, their incidence is approximately 1:1,000 live
births. Primary carnitine deficiency has an incidence of approximately 1:21,000 live births based on
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