PKU	Phenylketonuria
HPA	Hyperphenylalaninemia
BH4-r-HPA	Tetrahydrobiopterin-Responsive Hyperphenylalaninemia
CPKU	Classical Phenylketonuria
Phe	Phenylalanine
Tyr	Tyrosine
Trp	Tryptophan
Phe/Tyr	Phenylalanine to Tyrosine ratio
BMI	Body Mass Index
BW	Body Weight
IQR	Interquartile Range
SD	Standard Deviation
LC-MS/MS	Liquid Chromatography–Mass Spectrometry
Q-TOF	Quadrupole Time-of-Flight
CE	Collision Energy
DDA	Data-Dependent Analysis
PCA	Principal Component Analysis
PLS-DA	Partial Least Squares Discriminant Analysis
OPLS-DA	Orthogonal Partial Least Squares Discriminant Analysis
VIP	Variable Importance in Projection
MS	Mass Spectrometry
NMR	Nuclear Magnetic Resonance
ESI	Electrospray Ionization
QC	Quality Control
TG	Triglyceride
DG	Diglyceride
PC	Phosphatidylcholine
LPC	Lysophosphatidylcholine
SM	Sphingomyelin
PUFA	Polyunsaturated Fatty Acids
AGE	Advanced Glycation End Products
ARPs	Amadori Rearrangement Products
HbA1c	Hemoglobin A1c (glycosylated hemoglobin)
IRIS	Infrared Ion Spectroscopy
MRM	Multiple Reaction Monitoring
UHPLC	Ultra-High-Performance Liquid Chromatography
v/v	Volume/Volume
m/z	Mass-to-Charge-Ratio