Initial dried blood spot and follow up assays in 12 babies with persistently increased octanoylcarnitine and at least one copy of A985G
| Patient | Newborn screening | Biochemical genetics follow up | Fibroblast results | |||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Octanoyl- carnitine (μmol/l) (cut off <1) | A985G mutational analysis | Urinary acylglycines | Plasma carnitines (μmol/l) | Fatty acid oxidation rate assay % of intrabatch controls O:M ratio (0.7–1.3) | Acylcarnitine profile (nmol/mg/72 h) | ETF assays MCAD activity (Dr Vianey-Saban) (2.42 (0.61) n=50) | ||||||||||||||||||||||||
| Hexanoyl | Suberyl | C6 (<0.1) | C8 (<0.3) | C10:1 (<0.3) | C6 (0.2–1.4) | C8 (0.1–1.1) | C10 (0.6–1.6) | |||||||||||||||||||||||
| 1 | 24.6 | +/− | +++ | +++ | 0.6 | 2.0 | 0.3 | NP | 0.81 | 2.06 | 0.34 | NP | ||||||||||||||||||
| 2 | 14.2 | +/+ | NP | NP | 1.3 | 5.6 | 0.5 | NP | NP | NP | NP | NP | ||||||||||||||||||
| 3 | 13.0 | +/− | +++ | +++ | 1.0 | 3.8 | 0.6 | Ole 63%, Myr 10% | 2.90 | 6.97 | 1.25 | NP | ||||||||||||||||||
| O:M 6.4 | ||||||||||||||||||||||||||||||
| 4 | 8.6 | +/− | +++ | +++ | 0.9 | 3.8 | 0.3 | NP | 1.56 | 4.07 | 0.66 | NP | ||||||||||||||||||
| 5 | 8.0 | +/+ | +++ | +++ | 0.5 | 2.6 | 0.3 | NP | NP | NP | ||||||||||||||||||||
| 6 | 8.0 | +/+ | +++ | +++ | 1.3 | 8.4 | 2.5 | NP | NP | NP | ||||||||||||||||||||
| 7 | 8.0 | +/+ | +++ | +++ | 1.1 | 5.7 | 0.7 | NP | NP | NP | ||||||||||||||||||||
| 8 | 4.9 | +/− | ++ | ++ | 0.2 | 1.1 | 0.4 | Ole 51–87%, Myr 31–52% | 1.60 | 3.07 | 1.43 | NP | ||||||||||||||||||
| O:M 1.6–1.7 | ||||||||||||||||||||||||||||||
| 9 | 3.5 | +/− | + | ++ | 1.1 | 3.1 | 0.4 | NP | NP | NP | ||||||||||||||||||||
| 10 | 3.3 | +/− | + | + | 0.2 | 0.7 | 0.2 | Ole 107%, Myr 38% | 2.35 | 7.81 | 4.01 | NP | ||||||||||||||||||
| O:M 2.8 | ||||||||||||||||||||||||||||||
| 11 | 1.1 | +/− | TR, ND | TR, ND | 0.7 | 1.9 | 1.0 | Ole 41–59%, Myr 42–44% | 0.92 | 1.03 | 0.67 | 0.44, 0.31 | ||||||||||||||||||
| O:M 1.0–1.3 | ||||||||||||||||||||||||||||||
| 12 | 1.1 | +/− | ND | ND | NP | NP | NP | Ole 32%, Myr 22% | 1.45 | 1.52 | 1.11 | 1.28, 1.21 | ||||||||||||||||||
| O:M 1.5 | ||||||||||||||||||||||||||||||
Patients 1–11 were assigned a diagnosis of medium chain acyl-CoA dehydrogenase (MCAD) deficiency, and patient 12 was considered to be a carrier at low risk of developing symptoms. +/+, homozygous for A985G; +/−, heterozygous for A985G; Ole, oleate; Myr, myristate; O:M, oleate to myristate ratio; C4, butyrylcarnitine; C6, hexanoylcarnitine; C8, octanoylcarnitine; C10, decanoylcarnitine; C10:1, decenoylcarnitine; ND, not detected; NP, not performed; NI, not increased; +++, grossly elevated; ++, moderately increased; +, slightly increased; TR, trace increase.