Table 2.

Clinical and biologic manifestations at diagnosis

Variable	ABS/NBS (n=34)	CBS (n=51)	GLS (n=30)	P Value
				All	ABS/NBS versus CBS	ABS/NBS versus GLS	CBS versus GLS
Age at diagnosis, yr	0.1 (0.02–0.66)	1 (0.4–9.6)5	28 (18–42)2	<0.001	<0.001	<0.001	<0.001
GA at birth, wk	37 (36–40)6	40 (39–40)16	40 (40–40)12	0.001	0.002	0.001	ns
GA at onset of polyhydramnios, wk	28.25 (22–33)22
Weight at birth, g	2790 (2470–3380)8	3200 (2850–3500)23	3100(2960–3335)27	nd	—	—	—
Plasma concentrations
Sodium, 133–146 mmol/L	134 (131–136)12	133 (127–137)24	138 (136–140)17	nd	—	—	—
Potassium, 3.5–5 mmol/L	2.7 (2.4–3.1)5	2.6 (2.3–2.9)15	2.8 (2.5–3.0)5	0.21	—	—	—
Chloride, 90–117 mmol/L	87 (82–95)11	87 (74–95)24	97 (94–99)12	0.002	ns	0.001	0.003
CO2t, 18–25 mmol/L	33 (28–37)9	32 (28–36)18	31 (30–33)12	0.53	—	—	—
Calcium, 2.2–2.6 mmol/L	2.67 (2.49–2.80)12	2.54 (2.38–2.64)25	2.39 (2.32–2.52)13	0.001	ns	0.001	0.01
Magnesium, 0.75–1 mmol/L	0.95 (0.87–1.00)17	0.91 (0.76–1.00)22	0.77 (0.69–0.81)14	0.001	ns	0.001	ns
Renin, times the normal upper limit for age	11 (6–26)16	3 (1–15)26	1 (0–3)14	0.001	ns	<0.001	0.02
Aldosterone, times the normal upper limit	0.4 (0.3–2.0)15	2.0 (0.8–2.5)30	0.6 (0.2–1.3)16	nd	—	—	—
Urinary calcium-to-creatinine ratio, Z value	1.23 (0.27–2.13)13	0.70 (0.11–1.45)31	−0.37 (−2.77–0.62)21	nd
Nephrocalcinosis, %	29.4	14	3	0.01	0.1	0.01	0.25
Main symptoms, %
Failure-to-thrive	47	24	13	0.01	0.04	0.004	0.19
Polyuria	56	42	23	0.03	0.25	0.01	0.07
Asthenia/cramps	0	2	20	0.02	0.41	0.04	0.06
Fortuitous discovery of hypokalemia	0	0	40	<0.001	1	<0.001	<0.001

Values are expressed as medians and interquartile intervals. Superscript values correspond to the number of missing data. Calcium-to-creatinine ratio is expressed as a Z value relative to the normal values for age; hypercalciuria is defined by a Z value >2. nd, not done, >50% of the data missing in one or more groups; —, not done; CO₂t, total carbon dioxide.