Pediatric hypophosphatasia: lessons learned from a retrospective single-center chart review of 50 children

Table 3 Laboratory findings

	Perinatal HPP			Infantile HPP			Childhood HPP			All subtypes
	Median	Min	Max	Median	Min	Max	Median	Min	Max	Median	Min	Max
AP	0.5	0	18	30	20	77	45	19	139	31.5	0	139
(in U/l)	(n = 4)	0	18	(n = 17)	20	77	(n = 29)	19	139	(n = 50)	0	139
Calcium	2.82	2.5	3.6	2.5	2.25	3.72	2.48	2.2	2.8	2.5	2.2	3.72
(in mmol/l), [norm: 2.0–2.7]	(n = 4)	2.5	3.6	(n = 17)	2.25	3.72	(n = 28)	2.2	2.8	(n = 49)	2.2	3.72
Phosphate	1.91	1.09	2.52	2.02	1.26	2.36	2.03	1.25	2.64	2.02	1.09	2.64
(in mmol/l), [0.97–2.2]	(n = 4)	1.09	2.52	(n = 17)	1.26	2.36	(n = 28)	1.25	2.64	(n = 49)	1.09	2.64
25(OH)D	33.8	12.6	39	30.8	8.3	50.7	23.6	13.8	53	26.1	8.3	53
(µg/l), [30–70]	(n = 3)	12.6	39	(n = 15)	8.3	50.7	(n = 21)	13.8	53	(n = 39)	8.3	53
PTH	21.4	7	175	5.3	2	33.6	13.95	3	49	12.3	2	175
(in ng/l), [12–65]	(n = 3)	7	175	(n = 17)	2	33.6	(n = 24)	3	49	(n = 44)	2	175
PLP	substituted			150	62	774	120	30	446	142.5	30	774
(in ng/ml), [5–30]	substituted			(n = 11)	62	774	(n = 19)	30	446	(n = 30)	30	774

all diagnostic reference levels according to intern laboratory standards
AP alkaline phosphatase, 25(OH)D 25-OH-Vitamin D, PTH parathyroid hormone, PLP pyridoxal phosphate; * reference levels of AP (37 C°, IFCC method): infants 110–590 IU/l, toddler 110–550 IU/l, pupil 130–700 IU/l according to local laboratory standards)

ISSN: 1750-1172