Background: Neurofibromatosis, also known as Von Recklinghausen disease, is a systemic and progressive
genetic disease that primarily affects the skin, eyes, nervous system and bones. The disease can occur in a variety of ways
and can vary from individuals. Metabolomic-based research using blood samples has enabled new diagnostic methods to be
used in the diagnosis of various diseases, especially cancer. Among metabolites, profiling of plasma free amino acids
(PFAA) is a promising approach because PFAAs bind all organ systems and play an important role in metabolism.
Objective: This study aimed to determine the characteristics of PFAA profiles in neurofibromatosis patients and the
possibility of using them for early detection and treatment of the disease.
Method: Patients with a diagnosis of Neurofibromatosis Type I confirmed by genetic analysis and healthy individuals of the
same age group without any disease were included in the study. We analysed the nineteen plasma free amino acids
(phenylalanine, proline, threonine, arginine, asparagine, cystine, valine, glutamate, tyrosine, serine, glutamine, glycine,
tryptophane, leucine, lysine, methionine, isoleucine, aspartate and alanine) from neurofibromatosis Type I patients and
control group by liquid chromatography tandem mass spectrometry (LC-MS/MS) in Metabolism Laboratory of Harran
University Research and Application Hospital. The results of the plasma free amino acid levels were divided into 3 groups
as essential, semi-essential and non-essential. The differences of amino acid levels between groups were determined.
Results: Eight amino acid levels (methionine, arginine, cystine, glutamine, proline, asparagine, serine, aspartate) were
significantly altered in patients with neurofibromatosis type 1. In essential amino acids, methionine levels were significantly
higher in the patient group than the control group. While the levels of arginine and glutamine in semi-essential amino acids
were statistically significantly higher in the patient group, a significant decrease was observed in cystine and proline levels
compared to the control group's amino acid levels. In non-essential amino acids group, asparagine, serine and aspartate
amino acid levels were significantly higher in the patient group compared to the control group.
Conclusion: The current research predicates that eight amino acids, nsmely methionine, arginine, cystine, glutamine,
proline, asparagine, serine, aspartate can be considered to be valuable biomarkers for neurofibromatosis type I. This present
study is the first to build models for neurofibromatosis Type I screening using plasma free amino acids and the amino acid
profile will guide the predicting of the complications that may occur during the course of the disease.