Age-Specific Cut-off Values of Amino Acids and Acylcarnitines for Diagnosis of Inborn Errors of Metabolism Using Liquid Chromatography Tandem Mass Spectrometry
Table 2
Abnormal blood concentrations of metabolites and marker ratios together with clinical manifestations of the patients with suspected IEMs, as screened by LC-MS/MS.
Name of disorders
Total no. of positive cases (frequency among detected cases)
Case ID
Age at diagnosis
Metabolites or marker ratios
Concentrations of metabolites (mol/L) or marker ratios
Cut-offs (mol/L)
Major clinical complications
PKU
3 (33.3%)
Case 1
1.1 years
Phe
180.12
> 88.12
Lethargy, irritation, seizure and developmental delay
Phe/tyr
5.97
> 5.11
Case 2
1.0 year
Phe
282.45
> 88.12
Phe/tyr
6.30
> 5.11
Case 3
10.0 years
Phe
1170.32
> 82.08
Phe/tyr
46.58
> 8.03
CIT-II
1 (11.1%)
Case 4
10.0 years
Cit
1494.66
> 39.74
Irritability, restlessness and excessive crying followed by unconsciousness
Cit/Phe
26.68
> 0.80
MMA
1 (11.1%)
Case 5
1.0 year
C3
5.39
> 2.69
Developmental delay, seizure and low muscle tone
C3/C2
0.29
> 0.15
IVA
1 (11.1%)
Case 6
1.9 years
C5
13.80
> 0.26
Recurrent infection and developmental delay
C5/C3
25.07
> 0.16
CUD
1 (11.1%)
Case 7
2.0 years
C0
6.13
< 12.34
Lethargy, restless, poor feeding, seizure, vomiting, developmental delay, speech problem and inability of walking
C2
6.47
< 8.71
MCAD
2 (22.2%)
Case 8
10.0 years
C6
0.62
> 0.12
Restlessness, irritability, abnormal behavior, speech problem and mental retardation
