NM_181523.2:c.1011T>G (p.Asp337Glu) is a missense variant in exon 8 of PIK3R1. It is absent from all population databases including gnomAD v2.1, v4.1, and gnomAD-Canada, meeting the VCEP PM2_Supporting threshold for rarity (PM2_Supporting).¹ REVEL score is 0.333, which falls between the VCEP thresholds for PP3 (>= 0.644) and BP4 (<= 0.290); neither in silico criterion is met. SpliceAI predicts no splicing impact (max delta 0.02).² No functional studies have tested this variant in any VCEP-approved assay. The variant is absent from ClinVar with no prior classifications. No publications, case reports, or segregation data exist for this variant.³ Under the Bayesian point-based framework adopted by the Antibody Deficiencies VCEP, the only met criterion is PM2_Supporting (+1 point), yielding a total score of +1, which falls in the Uncertain Significance range (0-5 points).⁴