TABLE 1.

comparison of baseline demographic, clinical, and biochemical characteristics between patients with normal and poor outcomes.

Variable	Normal outcome	Poor outcome	p value
No.	298 (55.4%)	240 (44.6%)
Age at diagnosis (months)	1 (0.8–1.5)	1.5 (1–2.2)
Age during follow-up (years)	3.34 (0.63–4.52)	3.8 (0.48–5.25)
Biochemical features at NBS
C3	7.35 (4–22.47)	7.71 (4–31.5)	0.119
C3/C2	0.52 (0.2–9.19)	0.62 (0.21–3.27)	0.000
MMA	78.82 (5–3,253.72)	112.6 (5.3–2,348.8)	0.01
MCA	2.51 (0–397.13)	3.86 (0.17–209.1)	0.000
tHcy	102.99 (31–1,139)	131.2 (31–750)	0.02
Onset of symptoms, n (%)	63 (21.1%)	187 (77.9%)	0.000
Initial symptoms
Milk refusal, n (%)	37 (12.4%)	114 (47.5%)	0.000
Vomiting, n (%)	29 (9.7%)	71 (29.6%)	0.000
Drowsiness, n (%)	38 (12.8%)	105 (43.8%)	0.000
Seizures, n (%)	13 (4.4%)	41 (17.1%)	0.000
Coma, n (%)	5 (1.7%)	17 (7.1%)	0.002
Dyskinesia, n (%)	8 (2.7%)	82 (34.2%)	0.000
Developmental delay, n (%)	12 (4%)	80 (33.3%)	0.000
Treatment
With VB12 before onset	248 (83.2%)	89 (37.1%)
With VB12 after onset	50 (16.8%)	151 (62.9%)	0.000
Biochemical features during follow-up
C3	3 (0.06–10.83)	3.39 (0.16–13.96)	0.002
C3/C2	0.12 (0.01–0.36)	0.15 (0.02–0.39)	0.001
MMA	4.29 (0–45.19)	6.85 (0–49.57)	0.002
MCA	0.48 (0–4.99)	0.71 (0–4.95)	0.021
tHcy	30.15 (2–59)	35.35 (6.2–59.5)	0.000
Nucleotide variant
c.609G>A	173 (58.1%)	178 (74.2%)	0.000
c.658_660delAAG	52 (17.4%)	41 (17.1%)	0.911
c.80A>G	55 (18.5%)	26 (10.8%)	0.014
c.567dupT	20 (6.7%)	30 (12.5%)	0.022
c.482G>A	77 (25.8%)	10 (4.2%)	0.000
Others	140 (47%)	134 (55.8%)	0.041

Reference range: C3 in the blood: 0.5–4 μmol/L; C3/C2 in the blood: 0–0.2 μmol/L; MMA in the urine: 0–4 mmol/mol creatinine; MCA in the urine: 0–0.8 mmol/mol creatinine; tHcy in the blood: 0–15 μmol/L.