Table 3

Plasma vitamin B₆profiles of patients with PROSC mutations on pyridoxine and ranges for vitamin B₆ reference profiles of controls and patients with antiquitin, PNPO and TNSALP deficiency on pyridoxine5

	Age at sampling	Pyridoxine dosage	Interval to last intake	Vitamin B₆ vitamers in plasma (nmol/L)
	Age at sampling	Pyridoxine dosage	Interval to last intake	PLP	PL	PM	PN	PA
Patient 1	8 y	300 mg/day, 1 SD	NA	1040	779	<1	<1	969
	11 y	300 mg/day, 2 SD	9 hours	1050	629	<1	<1	1130
	12 y	300 mg/day, 2 SD	NA	1530	1400	2	<1	3050
	12.5 y	300 mg/day, 1 SD	2 hours	1460	11 500	26	5380	9990
			4 hours	1240	6810	12	151	7950
			6 hours	1590	2560	2	3	4380
			24 hours	1260	183	1	<1	317
Patient 2	15 y	150 mg/day, 2 SD	NA	2040	294	<1	<1	664
Patient 3	26 m	450 mg/day, 4 SD	8 hours	1840	198	<1	<1	317
Patient 4	30 y	300 mg/day, 3 SD	24 hours	652	33	<1	<1	70
Reference (n=50, range)				10–289	4–85	<1	<1	4–564
Patients with EE of unclear aetiology on pyridoxine (antiquitin, PNPO, TNSALP deficiency excluded) (n=8, range)				346–1070	210–16 300	1–186	4–22 200	1070–13 200
Patients with antiquitin deficiency on pyridoxine (n=21, range)				344–1740	117–13 900	<1–54	<1–14 700	149–10 200
Patients with PNPO deficiency on pyridoxine (n=6, range)				330–1080	389–7640	206–2170	1100–11 100	583–9610
Patients with TNSALP deficiency on pyridoxine (n=1, two samples, range)				1590–2030	1110–5570	<1–21	2–2330	1920–5950

EE, epileptic encephalopathy; m, months; NA, not available; PA, pyridoxic acid; PL, pyridoxal; PLP, pyridoxal 5’-phosphate; PM, pyridoxamine; PN, pyridoxine; SD, single dosage; y, years.
PLP, pyridoxal and pyridoxic acid were elevated due to pyridoxine substitution. PLP values exceeded values seen in other groups of patients on pyridoxine only in two out of four patients. The vitamin B₆ kinetic profile performed in P1 was comparable to healthy controls.5