The c.1247G>T (NM_000536.4) variant in RAG2 is a missense variant predicted to cause the substitution of Tryptophan by Leucine at amino acid 416 (p.Trp416Leu). The Popmax Filtering AF (95% confidence) in gnomAD v.4 is 0.0002998, based on 36/91078 alleles in the South Asian population. PM2_Supporting (<0.0000588), BS1 (>0.00195), and BA1 (>0.00872) are not met. No homozygotes have been observed in gnomAD (BS2 is not met). This variant is located in the PHD domain, amino acids 414-487 of RAG2, which is defined as a critical functional domain by the ClinGen SCID VCEP (PMID: 26996199); PM1. The variant was found in at least four individuals in the literature, with diagnostic criteria for SCID/Leaky SCID/Omenn syndrome met. All of them are homozygous, reaching 1 point for homozygous occurrence. PM3_Moderate (PMID: 17572155). Diagnostic criteria for SCID/Leaky SCID/Omenn syndrome met 0.5pts + T-B-NK+ lymphocyte subset profile 0.5pts; the total is 1 point, PP4 is met (PMID: 29772310). The recombination activity assay showed activity of this variant compared to wildtype RAG2 is 1.4% (SEM 0.2), which is lower than the SCID VCEP threshold (<25%) for PS3_Moderate, meeting this criterion (PS3_Moderate, PMID 29772310). In summary, this variant meets the criteria to be classified as Likely Pathogenic for autosomal recessive recombinase activating gene 2 deficiency based on the ACMG/AMP criteria applied, as specified by the ClinGen SCID VCEP. Criteria applied: PM1, PM3, PP4, and PS3_Moderate (VCEP specifications version 1.0).