IMD diagnosed in hospitalised newborns by pathophysiological group_
| Pathophysiological group | IMD | n |
|---|---|---|
| Small molecules (accumulation/intoxication) n=15 | Organic aciduria | 4 |
| Propionic aciduria | 1 | |
| Methylmalonic aciduria | 3 | |
| Maple syrup urine disease | 4 | |
| Urea cycle disorders | 3 | |
| Citrullinaemia type 1* | 2 | |
| Ornithine transcarbamylase deficiency (OTC) | 1 | |
| Galactosemia | 3 | |
| - Classic | 2 | |
| - Epimerase deficiency | 1 | |
| Nonketotic hyperglycinemia | 1 | |
| Small molecules (deficiency) n=1 | Asparagine synthetase deficiency | 1 |
| Energy defects n=4 | Carnitinepalmitoyltransferase 1 deficiency (CPT1) | 1 |
| Carnitine-acylcarnitine translocase deficiency (CACT) | 1 | |
| Multiple oxidative phosphorylation defect (complexes IV-V-II+IV) | 1 | |
| Combined oxidative phosphorylation defect type 13 | 1 |
Newborns’ demographic and clinical data (n=20)_
| Variable | |
|---|---|
| Age at PICU admission, median (IQR), days | 7.5 (3.25–9) |
| Female gender n (%) | 13 (65) |
| Gestational age, median (IQR), weeks | 38.5 (36–39) |
| Birth weight, mean (SD), grams | 2831.3 (523.1) |
| Neonatal resuscitation n (%) | 1 (5) |
| Pregnancy complications n (%) | 6 (30) |
| Family history of IMD n (%) | 4 (20) |
| Age at onset of symptoms, median (IQR), days | 5 (1–7) |
| Symptom-free interval n (%) | 16 (80) |
| Length of the symptom-free interval, median (OQR), days | 5 (1–7) |
Comparison of clinical manifestations between the two IMD groups_
| Small molecules n=16 | Energy defects n=4 | p | |
|---|---|---|---|
| Symptom-free interval n (%) | 15 (93.8) | 1 (25) | 0.01* |
| Length of the symptom-free interval, median (IQR), days | 5.5 (0–7.8) | 3 (0–6.8) | 0.3** |
| Encephalopathy n (%) | 14 (87.5) | 3 (75) | 0.5* |
| Hypotonia n (%) | 10 (62.5) | 2 (50) | 0.2* |
| Seizures n (%) | 6 (37.5) | 2 (50) | 1* |
| Acute liver failure n (%) | 3 (18.8) | 0 | 1* |
| Heart failure n (%) | 2 (12.5) | 2 (50) | 0.2* |
| Cardiac structural change n (%) | 3 (18.8) | 2 (50) | 0.4* |
| Death n (%) | 4 (25) | 1 (25) | 0.7* |
Main alterations of diagnostic tests by pathophysiological group of IMD_
| Diagnostic tests | Small molecules group (n=16) | Energy defects group (n=4) | p* |
|---|---|---|---|
| Altered plasma aminoacids, n (%) | 12 (75) | 1 (25) | 0.2 |
| CK elevation, n (%) | 11 (68.8) | 2 (50) | 0.6 |
| Hyperlactatemia, n (%) | 8 (50) | 4 (100) | 0.4 |
| Glomerular renal dysfunction, n (%) | 8 (50) | 3 (75) | 0.6 |
| Metabolic acidosis with increased anion gap, n (%) | 7 (43.8) | 1 (25) | 0.5 |
| Organic aciduria, n (%) | 7 (43.8) | 3 (75) | 0.2 |
| Abnormal urine aminoacids, n (%) | 7 (43.8) | 0 | 0.08 |
| Hyperammonemia, n (%) | 6 (37.5) | 1 (25) | 1 |
| DNPH urine test - positive, n (%) | 6 (37.5) | 0 | 0.2 |
| Hypoglycemia, n (%) | 6 (37.5) | 2 (50) | 0.4 |
| Thrombocytopenia, n (%) | 5 | 0 | 0.2 |
| Leukopenia, n (%) | 0 | 1 | 0.2 |