Table 2.

Clinical and biologic manifestations at diagnosis

VariableABS/NBS (n=34)CBS (n=51)GLS (n=30)P Value
AllABS/NBS versus CBSABS/NBS versus GLSCBS versus GLS
Age at diagnosis, yr0.1 (0.02–0.66)1 (0.4–9.6)528 (18–42)2<0.001<0.001<0.001<0.001
GA at birth, wk37 (36–40)640 (39–40)1640 (40–40)120.0010.0020.001ns
GA at onset of polyhydramnios, wk28.25 (22–33)22
Weight at birth, g2790 (2470–3380)83200 (2850–3500)233100(2960–3335)27nd
Plasma concentrations
 Sodium, 133–146 mmol/L134 (131–136)12133 (127–137)24138 (136–140)17nd
 Potassium, 3.5–5 mmol/L2.7 (2.4–3.1)52.6 (2.3–2.9)152.8 (2.5–3.0)50.21
 Chloride, 90–117 mmol/L87 (82–95)1187 (74–95)2497 (94–99)120.002ns0.0010.003
 CO2t, 18–25 mmol/L33 (28–37)932 (28–36)1831 (30–33)120.53
 Calcium, 2.2–2.6 mmol/L2.67 (2.49–2.80)122.54 (2.38–2.64)252.39 (2.32–2.52)130.001ns0.0010.01
 Magnesium, 0.75–1 mmol/L0.95 (0.87–1.00)170.91 (0.76–1.00)220.77 (0.69–0.81)140.001ns0.001ns
 Renin, times the normal upper limit for age11 (6–26)163 (1–15)261 (0–3)140.001ns<0.0010.02
 Aldosterone, times the normal upper limit0.4 (0.3–2.0)152.0 (0.8–2.5)300.6 (0.2–1.3)16nd
Urinary calcium-to-creatinine ratio, Z value1.23 (0.27–2.13)130.70 (0.11–1.45)31−0.37 (−2.77–0.62)21nd
Nephrocalcinosis, %29.41430.010.10.010.25
Main symptoms, %
 Failure-to-thrive4724130.010.040.0040.19
 Polyuria5642230.030.250.010.07
 Asthenia/cramps02200.020.410.040.06
 Fortuitous discovery of hypokalemia0040<0.0011<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.