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Table 3 Peak plasma ammonium concentration (before treatment)

From: Incidence, disease onset and short-term outcome in urea cycle disorders –cross-border surveillance in Germany, Austria and Switzerland

 

Patients

(n)

Median (Range)

(μmol/L)

Disease name

 CPS1-D

8

2333 (350–5400)

 mOTC-D

17

1714 (110–8160)

 fOTC-D

5

247 (73–498)

 ASS-D

10

422 (40–1266)

 ASL-D

7

320 (36–1471)

 ARG1-D

1

63 (n/a)

 HHH syndrome

1

60 (n/a)

 Citrin-D

1

44 (n/a)

 Total

50

935 (36–8160)

Onset typea

 EO

28

1622 (199–8160)

 LO

7

247 (60–498)

 Asymptomatic

10

68 (36–110)

 Unknowna

5

n/a

Initial hyperammonemia

 HE

5

320 (150–1383)

 HE + C

25

1945 (298–8160)

  1. Peak plasma ammonia levels are different between EO and LO groups (U-test, p < 0.0001) as well as between EO or LO and asymptomatic patients, respectively (U-test, p < 0.001). Note that plasma ammonium concentrations are age-dependent: Newborns (arterial cord blood), 50–159 μmol/L; infants and children, 24–48 μmol/l; adults, 11–55 μmol/L (adapted from [38]). Peak plasma ammonia levels differed between groups AS, HE and HE + C [ART ANOVA: F(2,37) = 36.63; p < 0.001]. Contrasts with Tukey p-value adjustment revealed significant differences between all three groups: AS vs. HE (p = 0.024), AS vs. HE + C (p < 0.001) and HE vs. HE + C (p = 0.005). EO, early onset; HE, hyperammonemic encephalopathy; HE + C, HE with coma; LO, late onset; n/a, not applicable
  2. aFive patients in whom clinical information was not available since they have been exclusively reported by metabolic laboratories