Acylcarnitine Profile – Interpretive Guide

An acylcarnitine profile is a blood test used to check for the presence of genetic disorders related to fatty acid oxidation and several organic acidurieas. If a patient is at risk of having these disorders or is suspected of having it, the doctor may order the test.

Carnitine is a generic name given to a number of compounds formed primarily from the building blocks of proteins (amino acids) by the kidneys and liver which play an important role in converting fats into energy for cell function (metabolism). If the body is deficient in the enzymes that do this, (fatty acid oxidation disorders), either as a “primary “ deficiency associated with genetic abnormalities or “secondary” carnitine deficiency, it can lead to increased amounts of acylcarnitine in the blood which may present with brain dysfunction, a weakened heart, confusion, weakness and other signs and symptoms. A biochemical genetic test for acylcarnitine is used to screen for these disorders.

Basic acylcarnitine patterns associated with various disease states:

Results should be reviewed and interpreted by an ABMG-certified biochemical geneticist. Informative results are usually characterized by a pattern of one or more elevated acylcarnitine species in comparison with age-matched reference ranges. Interpretation of results is based on pattern recognition and correlation of positive and negative findings, rather than on individual abnormal values.

Common acylcarnitine patterns associated with various disease states:

H –> high

H? –> high but specific isomeric species are not clearly defined for this disorder

L –> low

V –> level varies from high-normal to elevated

1: CUD carnitine uptake deficiency,

2: CPT1A carnitine palmitoyltransferase I deficiency,

3: PA propionic acidemia,

4: MMA methylmalonic acidemia,

5: SUCLA succinyl-CoA ligase deficiency,

6: SCAD short-chain acyl-CoA dehydrogenase,

7: EE ethylmalonic encephalopathy,

8: IBD isobutyryl-CoA dehydrogenase deficiency,

9: IVA isovaleryl-CoA dehydrogenase deficiency,

10: SBCAD short/branched-chain acyl-CoA dehydrogenase deficiency,

11: HADH 3-hydroxyacyl-CoA dehydrogenase,

12: HIBCH 3-hydroxyisobutyryl-CoA hydrolase deficiency,

13: 3-MCC 3-methylcrotonyl-CoA carboxylase deficiency,

14: HMG HMG-CoA lyase deficiency,

15: BIO biotinidase or holocarboxylase synthetase deficiency,

16: 3MG 3-methylglutaconyl-CoA hydratase deficiency (AUH),

17: BKT β-ketothiolase deficiency,

18: MHBD 2-methyl-3-hydroxybutyryl-CoA dehydrogenase deficiency,

19: MCT supplementation with medium-chain triglycerides,

20: MCAD medium-chain acyl-CoA dehydrogenase deficiency,

21: Malonic aciduria malonyl-CoA decarboxylase deficiency,

22: GA1 glutaric aciduria type 1,

23: NADK2 dienoyl-CoA reductase deficiency caused by mitochondrial NAD kinase 2 deficiency,

24: VLCAD very long–chain acyl-CoA dehydrogenase deficiency,

26: CPT II/CACT carnitine palmitoyltransferase II/carnitine-acylcarnitine translocase deficiency,

27: LCHAD/TFP longchain L-3-hydroxyacyl-CoA dehydrogenase/trifunctional protein deficiency,

28: MAD multiple acyl-CoA dehydrogenase deficiency.

Class

Acylcarnitine

CUD

CPT1A

PA

MMA

SUCLA

SCAD

EE

IBD

IVA

SBCAD

HADH

HIBCH

3MCC

HMG

BIO

3MG

BKT

MHBD

MCT

MCAD

Malonic aciduria

GA1

NADK2

VLCAD

Ketosis

CPTII/CACT

LCHAD/TFP

MAD

C0

Free carnitine

L

H

C2

Acetyl

L

H

C3

Propionyl

H

H

H

H

C4

Butyryl

H

H?

H

Isobutyryl

H

H

C5:1

Tiglyl

H

H

3-Methylcrotonyl

H

C5

Isovaleryl

H?

H

H?

2-Methylbutyry

H

C6

Hexanoyl

H

H

H

C8:1

Octenoyl

C8

Octanoyl

H

H

H

C10:2

Decadienoyl

H

C10:1

Decenoyl

H

H

C10

Decanoyl

H

V

H

C12:1

Dodecenoyl

H

C12

Dodecanoyl

H

H

C14:2

Tetradecadienoyl

H

H

H

C14:1

Tetradecenoyl

H

H

H

C14

Tetradecanoyl

H

H

H

H

C16:1

Hexadecenoyl

L

H

H

H

H

C16

Hexadecanoyl

L

H

H

H

H

H

C18:2

Octadecadienoyl

L

H

H

H

H

H

C18:1

Octadecenoyl

L

H

H

H

H

H

C18

Octadecanoyl

L

H

H

H

H

H

C3-DC

Malonyl

H

C4-DC

Methylmalonyl

V

Succinyl

H

C5-DC

Glutaryl

H

C6-DC

3-Methylglutaryl

H

C4-OH

3-Hydroxybutyryl

H

H

3-Hydroxyisobutyryl

H

C5-OH

3-Hydroxyisovaleryl

H

H

H

H

3-Hydroxy-2-methylbutyry

H

H

C14-OH

Hydroxytetradecanoyl

H

C16-OH

3-Hydroxyhexadecanoyl

H

C18-OH

3-Hydroxyoctadecanoyl

H

ratio

C3 / C2

H

H

H

H

ratio

C8 / C10

H

ratio

C14:1 / C12:1

H

V

V

V

ratio

C0 / (C16+C18)

H

L

ratio

(C16+C18:1) / C2

V

H

V

V

Disclaimer:

Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. 

The information on healthmatters.io is NOT intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice.