Table 2.
Summarized patient and D,L-3-hydroxybutyrate treatment characteristics according to outcome.
| Clinical improvement upon D,L-3-HB treatment | |||
|---|---|---|---|
| Yes (n = 16; 70%) | Questionable (n = 3; 13%) | No (n = 4; 17%) | |
| Gender | M:F = 9:7 | M:F = 1:2 | M:F = 0:4 |
| Alive | 12 (75%) | 2 (67%) | 3 (75%) |
| Current age | 13 years (6.5 years) | 3 years (1.5 years) | 13.5 years (10.5 years) |
| Age at death | 1.5 years (8 years) | 8 months | 10 days |
| Age at onset | 3 months (8 months) | 3 days (5 months) | 3 months (5 years) |
| Congenital anomalies | - | - | - |
| Positive NBS results | 8 (50%) | 3 (100%) | 2 (50%) |
| Genetic analysis | 14 (88%) | 3 (100%) | 4 (100%) |
| ETFA | 5a | - | 1 |
| ETFB | - | - | - |
| ETFDH | 8 | 3 | 2b |
| SLC52A3 | 1 | - | 1 |
| Enzyme assay | 6 (38%) | 1 (33%) | 2 (50%) |
| ETF deficiency | 1 | - | - |
| ETF-QO deficiency | 4c | 1 | 1 |
| D,L-3-HB treatment | |||
| Age at start | 1.5 years (6 years) | 6 months (2 years) | 5 months (6.5 years) |
| Minimum D,L-3-HB dose (mg/kg/day) | 330 (215) | 200 (105) | 490 (215) |
| Maximum D,L-3-HB dose (mg/kg/day) | 650 (400) | 395 (925) | 905 (330) |
| Maximum number of doses/day | 4 (0.3)d | 4 (1.5) | 4 (0.5)e |
| D,L-3-HB discontinuation | 7 (44%) | 2 (33%) | 3 (75%) |
| Age at discontinuation | 6 years (17 years) | 1 year (5 months) | 3.5 years (13 years) |
| D,L-3-HB treatment duration | 3 years (7.5 years) | 6 months (5 months) | 2 years (3.5 years) |
Values are presented as number of patients or median (interquartile range [IQR]).
NBS newborn screening.
aIn one patient, DNA analysis also demonstrated compound heterozygous variants in ETFB (c.217–4G>T and c.438+20C>T), which were classified as variant of uncertain significance and likely benign, respectively.
bIn one patient only one pathogenic variant identified.
cIn one patient only performed in sister.
dContinuous nocturnal administration (n = 4).
eContinuous nocturnal administration (n = 1) and continuous 24-hour administration (n = 1).