Table 1.

Age-dependent lysine restriction according to the PDE Consortium^a

Age (year)	Lysineb,c (mg/kg)	Proteind,e (g/kg)	Energy
0.0 < 0.5	70–100	2.75–3.50	125–145 kcal/kg
1.0 < 1.0	55–70	2.50–3.25	140–115 kcal/kg
1 < 4	50–80	1.80–2.60	900–1,800 kcal/day
4 < 7	40–70	1.60–2.00	1,300–2,300 kcal/day
7 < 11	35–65	1.55–1.85	1,600–2,800 kcal/day
Female
11 < 15	35–40	1.50–1.80	1,500–2,800 kcal/day
15 < 19	33–40	1.45–1.75	1,200–2,800 kcal/day
>19	30–40	1.45–1.75	1,400–2,400 kcal/day
Male
11 < 15	35–40	1.45–1.75	2,000–3,200 kcal/day
15 < 19	33–45	1.45–1.75	2,100–3,200 kcal/day
>19	30–40	1.45–1.75	2,000–3,000 kcal/day

^aThese recommendations are based on the guidelines published for GA-I by Kölker et al. (2011) and Yanicelli (2010), and adapted for PDE by the Consortium based on experience

^bThe lysine/protein ratio varies considerably in natural food: thus natural protein intake in children on a low lysine diet is dependent on the source

^cThe continued chronic damage model in PDE requires as low as reasonably possible-chronic lysine levels. This contrasts with GA1, where currently the focus is on preventing damage during acute episodes. In some cases, this translates into lower intakes in PDE than currently recommended in GA1

^dTryptophan restriction is not needed in the management of PDE, in contrast to GA-I. Lysine-free amino acid formulas developed for managing GA-I are often low in tryptophan. The individual’s diet should be assessed for tryptophan adequacy and, if inadequate, should be supplemented

^eLysine-free amino acid mixtures should be supplemented with minerals and micronutrients necessary to maintain normal levels. Adequate intake of essential amino acids is provided by natural protein and lysine-free amino acid supplements. The amount of amino acid supplementation is adjusted to meet 130% of the patient’s age-appropriate DRI (Table C)