Median age of the 16 PA patients at the end of the study was 8.91 years (range: 1.38-22.48 years). In total, 259 episodes of metabolic decompensation were documented. Twenty-nine percent of metabolic decompensations occurred during the first year of life. Median number of metabolic decompensations per patient was 16 (range: 3-53). With increasing age metabolic decompensations occurred less often (Figure 1). Within the same time period 625 routine follow-up visits were documented accounting for a median number of four routine visits per year and patient. With increasing age the frequency of routine follow-up visits decreased. Vomiting was the most frequently observed clinical symptom (87% of metabolic decompensations), whereas food refusal (23%) and impaired consciousness (10%) were less often reported. Intercurrent infectious diseases preceded 44% of metabolic decompensations; 39% of them were febrile. Seven percent of decompensations occurred within one week after vaccination.
Biochemical parameters of metabolic decompensation Group 1 (no symptoms of metabolic decompensation) comprised 625 regular visits, group 2 (vomiting and/or food refusal but unaffected consciousness) 233 unscheduled visits and group 3 (symptoms of metabolic decompensation with impaired consciousness) 26 unscheduled visits. Nineteen of the 38 analysed biochemical parameters showed significant differences between the 3 groups (supplementary Table 2, for reference values see supplementary Table 1).
1) Primary parameters Organic acids, acylcarnitines, carnitine status, amino acids None of the analysed parameters of the organic acids and the acylcarnitines were discriminative. The ratio of acylcarnitines to free carnitine (AC/FC) was higher in group 3 than in group 1 (p
