Identification and Functional Validation of Novel Pathogenic Variants in Primary Immunodeficiencies

Area of Science:

• Immunology
• Genetics
• Molecular Biology

Background:

• Primary immunodeficiency diseases (PIDs) are inherited immune system disorders.
• Many PIDs lack genetic characterization due to unclear variant pathogenicity, hindering diagnosis.
• Next-generation sequencing (NGS) aids in identifying molecular defects in PIDs.

Purpose of the Study:

• To identify novel genetic variants in PID-related genes.
• To functionally validate identified variants for clinical significance.
• To improve the diagnostic process for primary immunodeficiencies.

Main Methods:

• Whole-exome sequencing (WES) was employed to screen for genetic variants.
• Functional validation assays included pSTAT1, DHR, and CRISPR-mediated genome editing.
• Analysis focused on five novel variants in FCHO1, NCF2, STAT1, and LRBA genes across six families.

Main Results:

• Five novel variants were identified: FCHO1 (E44K), NCF2 (A206P), NCF2 (c.174 + 1G > A), STAT1 (L199F), and an LRBA copy number deletion.
• Functional validation confirmed the pathogenicity of STAT1 (L199F), NCF2 variants, and FCHO1 (E44K).
• The study expands the catalog of known variants associated with primary immunodeficiency.

Conclusions:

• The identified variants represent new genetic causes of primary immunodeficiency.
• Functional validation is essential for interpreting rare variants in PID diagnosis.
• This research contributes to a better understanding and diagnosis of PIDs.