Platform
Company
Immunology & Autoimmune
Review status
Currently under review
Pending specialist review and validation.
This test measures C16:1 palmitoleylcarnitine, a long‑chain acylcarnitine formed when the fatty acid palmitoleic acid is linked to carnitine for transport into mitochondria. Acylcarnitines act as carriers that help move fatty acids into cells’ energy factories, where they are broken down to produce energy.
C16:1 is part of many acylcarnitine profiles used in newborn screening and in targeted evaluations for inherited disorders of fatty acid oxidation. The measurement is typically performed on blood using tandem mass spectrometry, which can detect very small amounts of these molecules.
Abnormal C16:1 levels can signal problems with how your body uses fats for energy. Patterns involving C16:1, especially alongside other long‑chain acylcarnitines, may suggest specific fatty acid oxidation disorders such as defects in mitochondrial transport or enzymes that handle long‑chain fats. Clinicians may order this test when investigating unexplained low blood sugar, muscle pain or weakness, dark urine from muscle breakdown, heart problems, or severe illness in infants and children.
Results can also change during times of fasting, infection, or other stress, because your body relies more on fat for fuel. Interpreting this marker together with other acylcarnitines, clinical history, and additional lab tests helps your care team decide whether further evaluation or treatment is needed.
Your result is interpreted using age‑specific reference intervals and in the context of other acylcarnitines. A single result outside the reference interval does not by itself diagnose a condition. Temporary factors such as recent illness, reduced food intake, strenuous exercise, or certain medicines can influence acylcarnitine levels.
If your level is higher than expected, your clinician may repeat the test when you are well, review your diet and medications, and order complementary tests such as a comprehensive acylcarnitine profile, free and total carnitine, urine organic acids, and possibly genetic testing. If your level is lower than expected, this can be seen with low carnitine stores or specimen issues, and your clinician may confirm with repeat testing and related studies. Discuss any concerns with your healthcare provider so results can be interpreted accurately and next steps can be tailored to you.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
Periods of fasting, fever, or acute illness shift the body toward using fat for energy, which can increase long‑chain acylcarnitines like C16:1. Testing during recovery may yield different results.
Valproate, pivalate‑containing antibiotics, and some anticonvulsants can lower carnitine stores or alter acylcarnitine patterns. L‑carnitine supplements can raise total carnitine and affect profiles.
High‑fat diets and medical foods containing medium‑chain triglycerides can change acylcarnitine patterns. Let your clinician know about specialized formulas, oils, or supplements you use.
Newborns and young infants have different reference intervals due to developmental changes in fat metabolism. Premature infants may show distinct patterns that require age‑appropriate interpretation.
Hemolysis, delayed processing, or prolonged storage at warm temperatures can affect results. Consistent collection timing and proper storage improve reliability and comparability.
Liver disease can alter fatty acid handling, and kidney impairment can change carnitine and acylcarnitine clearance, both of which may influence C16:1 levels.
References