Infection-related hyperammonemia in patients with urea cycle disorders is an important cause of morbidity and mortality. The relationship between immune system cells and the metabolic pathways used by these cells and inborn errors of metabolism is still under investigation. Current studies are generally based on experiments in mice. The investigators' goal is to study specific T cell subsets to understand the effects of the urea cycle on T cells.

The investigators collected blood samples from participants with lysinuric protein intolerance and urea cycle disorders for basic immunophenotyping, lymphocyte proliferation in response to phytohemagglutinin and CDmix, and cytokine analysis involving Th1, Th2, and Th17 and compared them with age-matched healthy controls. They also examined amino acid profiles in sera and supernatants before and after stimulation with PMA-ionomycin.

The investigators aim to compare cellular immune response of T cell phenotype and proliferative functions in addition to lymphocyte subset analysis between urea cycle disorders and healthy controls.

Complete blood counts, immunoglobuline levels, lymptocyte subset analysis and Thelper cells will be analyzed. Additionally, T helper cells will be measured regarding their cytokine profile as Th1, Th2 and Th17. T cell proliferation response and aminoacid profiles in supernatants before and after stimulation will be measured.

Inclusion Criteria:

• Children without any chronic conditions and having normal immunoglobulins and lymphocyte subsets

Exclusion Criteria:

• For healthy control, children having any signs for primary immune deficiencies

patients with a diagnosis of urea cycle disorders and lysinuric protein intolerance