Unique Lipoprotein Profile in Patients with Phenylketonuria Demonstrated with NMR Spectroscopy

Phenylketonuria, a rare metabolic disorder, is caused by mutations in phenylalanine hydroxylase (PAH) gene and results in high phenylalanine (Phe) in blood and the brain.

In this study, 22 patients with PKU (mean age 38.7 years) and 14 control patients (mean age 35.2 years) were included. Plasma with NMR spectroscopy and quantified 105 lipoprotein parameters (including lipoprotein subclasses) and 24 low molecular weight parameters were investigated.

In PKU patients versus controls, total cholesterol was significantly lower (179.4 vs 200.9 mg/dL [P < 0.02]) as well as LDL-cholesterol (79.5 vs 104.1 mg/dL [P < 0.0038]). Lower levels of 22 LDL subclasses were found in patients with PKU and there was a negative correlation of total cholesterol and LDL-cholesterol with concurrent Phe level. VLDL5-free cholesterol, VLDL5-cholesterol, VLDL5-phospholipids, and VLDL4-free cholesterol showed a significant (P < 0.05) negative correlation with concurrent Phe level. When compared with control, patients with PKU Tyrosine, glutamine, and creatinine were significantly lower whereas citric and glutamic acids were significantly higher.

The authors concluded that, “Using NMR spectroscopy, a unique lipoprotein profile in PKU patients can be demonstrated which mimics a non-atherogenic profile as seen in patients treated by statins.”

Reference

Cannet C, Pilotto A, César Rocha J, et al. Lower plasma cholesterol, LDL-cholesterol and LDL-lipoprotein subclasses in adult phenylketonuria (PKU) patients compared to healthy controls: results of NMR metabolomics investigation. Orphanet J Rare Dis. 2020;15(1):61.