Figure 1.
Screening protocol for MCAD deficiency.
C6, C8, C10 concentrations were determined and expressed in μmol/L, MSMS - tandem mass spectrometry, MRM - Multiple Reaction Monitoring, GC-MS - Gas Chromatography-Mass Spectrometry.
Table 1.
C8 levels for typical MCAD cases from our cohort in newborn screening (first and second dried blood spot samples).
| Sample collection day of life | Number of cases | Reference range ≤1 month (µmol/L) | Mean (µmol/L) | SD (µmol/L) | Median (µmol/L) | Q1 (µmol/L) | Q3 (µmol/L) |
|---|---|---|---|---|---|---|---|
| 3 | 61 | ≤ 0.27 | 7.93 | 5.77 | 6.28 | 3.00 | 12.06 |
| 4 | 23 | 6.06 | 4.11 | 4.31 | 3.34 | 7.32 | |
| 5 | 3 | 2.21 | 0.50 | 2.15 | 1.95 | 2.44 | |
| 8 | 12 | 1.63 | 0.63 | 1.58 | 1.27 | 1.84 | |
| 9 | 8 | 1.63 | 0.49 | 1.61 | 1.49 | 1.86 | |
| 10 | 5 | 1.88 | 0.60 | 1.53 | 1.50 | 2.30 | |
| 11 | 12 | 1.74 | 1.21 | 1.61 | 1.14 | 2.16 | |
| 12 | 12 | 1.29 | 0.95 | 1.46 | 0.37 | 1.85 |
Table 2.
Results of the newborn with an atypical MCAD acylcarnitine profile.
| Acylcarnitne | MS/MS test | ||||
|---|---|---|---|---|---|
| 5 day | Reference range ≤1 month | 34 day | 52 day | Reference range >1 month | |
| C6 (µmol/L) | 0.16 | ≤ 0.26 | 0.89 | 0.77 | ≤ 0.42 |
| C8 (µmol/L) | 0.78 | ≤ 0.27 | 5.61 | 3.30 | ≤ 0.68 |
| C10 (µmol/L) | 0.11 | ≤ 0.45 | 0.34 | 0.28 | ≤ 1.20 |
| C8/C10 (ratio) | 7.15 | ≤ 3.10 | 16.60 | 11.80 | ≤ 2.76 |
Figure 2.
Octanoylcarnitine (C8) concentrations in typical MCAD cases (group mean) versus the atypical case, plotted by the day of life at sampling.