Evaluation of Metabolic Defects in Fatty Acid Oxidation Using Peripheral Blood Mononuclear Cells Loaded with Deuterium-Labeled Fatty Acids

Table 1

Profiles of patients with VLCAD deficiency, CPT-II deficiency, and TFP deficiency.

Patients

Clinical form

Screening markers of acylcarnitine in DBS for NBS (μM)

Diagnostic markers of acylcarnitine in serum (μM)

Residual enzyme activity^a (%)

Diagnosis

No.

C14:1 <0.4

C16 <6.3^†

C16-OH <0.05

C18:1-OH <0.05

C0/(C16+C18) <100

C14:1 0.08 (0.04)^‡

C16 0.09 (0.04)^‡

C16-OH 0.005 (0.001)^‡

C18:1-OH 0.005 (0.001)^‡

VLCAD deficiency

1^b

Severe neonatal

4.08

ND

0.017

2

Myopathic

4.57

3.42

11.5

3

Myopathic

2.72

6.49

5.6

4

Myopathic

ND

2.62

9.4

5

Myopathic

ND

1.19

NT

CPT-II deficiency

1

Infantile

3.45

3.01

NT

2

Infantile

9.93

4.14

NT

3

Myopathic

5.07

1.57

NT

4^c

Myopathic

12.20

3.02

NT

5^d

Myopathic

10.82

2.17

NT

6^e

Myopathic

ND

0.62

NT

TFP deficiency

1

Infantile

ND

ND

0.220

0.180

NT

2^f

Myopathic

ND

ND

0.059

0.076

NT

3^g

Myopathic

ND

ND

0.093

0.129

NT

CPT-I deficiency

1

Asymptomatic

267

NT

2

Infantile

133

NT

3

Asymptomatic

127

NT

NT: not tested; ND: no data; C0: free carnitine; C14:1: tetradecenoylcarnitine; C16: hexadecanoylcarnitine; C16-OH: hydroxy-hexadecanoylcarnitine; C18:1-OH: hydroxy-octadecenoylcarnitine; C18: octadecanoylcarnitine. Cutoff value in NBS. ^†Cutoff value in NBS when these patients were diagnosed. ^‡Mean (SD) of 35 controls without starvation. ^aEnzyme activity is presented as a percentage of the mean of the normal control [7]. ^bPatient details were previously reported by Yamamoto et al. [14]. ^c,dNos. 4 and 5 with CPT-II deficiency were siblings. ^ePatient details were previously reported by Matsumoto et al. [13]. ^f,gNos. 2 and 3 with TFP deficiency were siblings.