Novel variants related to extreme elevation of serum IgE in Vietnamese patients with primary immunodeficiency: Case report.

RATIONALE: Extreme elevation of serum immunoglobulin E (IgE) concentration is a key marker for detecting immune disorders, including humoral and cellular defects in primary immunodeficiency (PID). IgE antibodies are present in low concentrations in the body and are produced in large amounts when exposed to infections or toxins. However, IgE is also the cause of allergic symptoms and life-threatening anaphylaxis reactions. Early diagnosis of PID associated with elevated IgE may lead to effective or life-saving therapeutic interventions. Therefore, genomic testing-based diagnosis is becoming a widely used diagnostic tool to determine the cause of disease. PATIENT CONCERNS: Three Vietnamese patients with increased IgE expression were collected for genetic analysis at The Allergy, Immunology, and Rheumatology Department, Vietnam National Hospital Pediatrics. DIAGNOSES: Primary immunodeficiency associated with elevated IgE. INTERVENTIONS: We performed whole-exome sequencing (WES) to detect novel associated variants and confirmed these by Sanger sequencing. The effects of the variants were predicted using in silico prediction tools. OUTCOMES: Three novel pathogenic variants including c.2204A > T, p.Asp735Val in the PTPRC gene, c.586T > A, p.Phe196Ile in the UNC119 gene, and c.481C > T, p.Arg161Cys in the IL21R gene were found to be associated with increased IgE. LESSONS: We report novel variants associated with genetic defects that increase IgE found in PID patients. These results emphasize the need for accurate diagnosis and appropriate intervention to improve outcomes and quality of care for individuals with high IgE levels and related immune disorders.