content:acycarnitines

suspected fatty acid oxidation disorders, acute myopathy, rhabdomyolysis, unexplained increased creatine kinase

diagnostic results are usually characterized by a pattern of significantly elevated acylcarnitine species compared to normal and disease controls.
serum acylcarnitines are useful in the diagnosis of fatty acid oxidation disorders and several organic acidurias
serum acylcarnitines also useful in evaluating treatment during follow-up of patients with fatty acid beta-oxidation disorders and several organic acidurias
specific acylcarnitines indicate particular disorders, e.g. octanoyl carnitine in MCAD deficiency, glutaryl carnitine in GA1, propionyl carnitine in cobalamin disorders
abnormal results are not sufficient to conclusively establish a diagnosis of a particular disease
to verify a preliminary diagnosis based on an acylcarnitine analysis, independent biochemical (eg, in vitro enzyme assay) or molecular genetic analyses are required.

Fatty acid oxidation (FAO) plays a major role in energy production during periods of fasting. When the body's supply of glucose is depleted, fatty acids are mobilized from adipose tissue, taken up by the liver and muscles, and oxidized to acetyl-CoA. In the liver, acetyl-CoA is the building block for the synthesis of ketone bodies, which enter the blood stream and provide an alternative substrate for production of energy in other tissues when the supply of glucose is insufficient to maintain a normal level of energy. The acyl groups are conjugated with carnitine to form acylcarnitines, which are measured by tandem mass spectrometry (MS/MS).

	8 days-7 years	> or =8 years
< or =7 days (nmol/mL)	(nmol/mL)	(nmol/mL)
Acetylcarnitine, C2	2.14-15.89	2.00-27.57	2.00-17.83
Acrylylcarnitine, C3:1	<0.04	<0.05	<0.07
Propionylcarnitine, C3	<0.55	<1.78	<0.88
Formiminoglutamate, FIGLU	<0.43	<0.08	<0.14
Iso-/Butyrylcarnitine, C4	<0.46	<1.06	<0.83
Tiglylcarnitine, C5:1	<0.05	<0.09	<0.11
Isovaleryl-/2-Methylbutyrylcarn C5	<0.38	<0.63	<0.51
3-OH-iso-/butyrylcarnitine, C4-OH	<0.13	<0.51	<0.18
Hexenoylcarnitine, C6:1	<0.12	<0.10	<0.15
Hexanoylcarnitine, C6	<0.14	<0.23	<0.17
3-OH-isovalerylcarnitine, C5-OH	<0.08	<0.12	<0.10
Benzoylcarnitine	<0.13	<0.07	<0.10
Heptanoylcarnitine, C7	<0.05	<0.05	<0.06
3-OH-hexanoylcarnitine, C6-OH	<0.08	<0.19	<0.09
Phenylacetylcarnitine	<0.15	<0.22	<0.29
Salicylcarnitine	<0.08	<0.09	<0.09
Octenoylcarnitine, C8:1	<0.48	<0.91	<0.88
Octanoylcarnitine, C8	<0.19	<0.45	<0.78
Malonylcarnitine, C3-DC	<0.09	<0.14	<0.26
Decadienoylcarnitine, C10:2	<0.11	<0.12	<0.26
Decenoylcarnitine, C10:1	<0.25	<0.46	<0.47
Decanoylcarnitine, C10	<0.27	<0.91	<0.88
Methylmalonyl-/succinylcarn, C4-DC	<0.05	<0.05	<0.05
3-OH-decenoylcarnitine, C10:1-OH	<0.12	<0.12	<0.13
Glutarylcarnitine, C5-DC	<0.06	<0.10	<0.11
Dodecenoylcarnitine, C12:1	<0.19	<0.37	<0.35
Dodecanoylcarnitine, C12	<0.18	<0.35	<0.26
3-Methylglutarylcarnitine, C6-DC	<0.28	<0.21	<0.43
3-OH-dodecenoylcarnitine, C12:1-OH	<0.11	<0.10	<0.13
3-OH-dodecanoylcarnitine, C12-OH	<0.06	<0.09	<0.08
Tetradecadienoylcarnitine, C14:2	<0.09	<0.13	<0.18
Tetradecenoylcarnitine, C14:1	<0.16	<0.35	<0.24
Tetradecanoylcarnitine, C14	<0.11	<0.15	<0.12
Octanedioylcarnitine, C8-DC	<0.25	<0.19	<0.19
3-OH-tetradecenoylcarnitine C14:1OH	<0.06	<0.18	<0.13
3-OH-tetradecanoylcarnitine, C14-OH	<0.04	<0.05	<0.08
Hexadecenoylcarnitine, C16:1	<0.15	<0.21	<0.10
Hexadecanoylcarnitine, C16	<0.36	<0.52	<0.23
3-OH-hexadecenoylcarnitine,C16:1-OH	<0.78	<0.36	<0.06
3-OH-hexadecanoylcarnitine, C16-OH	<0.10	<0.07	<0.06
Octadecadienoylcarnitine, C18:2	<0.12	<0.31	<0.24
Octadecenoylcarnitine, C18:1	<0.25	<0.45	<0.39
Octadecanoylcarnitine, C18	<0.10	<0.12	<0.14
Dodecanedioylcarnitine, C12-DC	<0.10	<0.04	<0.04
3-OH-octadecadienoylcarn, C18:2-OH	<0.04	<0.06	<0.06
3-OH-octadecenoylcarnitine C18:1-OH	<0.03	<0.04	<0.06
3-OH-octadecanoylcarnitine, C18-OH	<0.03	<0.05	<0.03

source: Mayo Clinic Labs

Table of Contents

Acylcarnitines

Indications

Notes

Pathophysiology

Reference values