NM_004606.4:c.3811_3812delinsCC (p.Lys1271Pro) is an in-frame deletion-insertion in TAF1 resulting in a missense substitution at codon 1271. This variant is absent from gnomAD v2.1, v4.1, and gnomAD-Canada v1.0, meeting PM2 at moderate strength.¹ The variant is absent from ClinVar, providing no external pathogenic or benign classification.² No variant-specific functional data, segregation data, de novo reports, or case-control studies are available for this variant. In silico splice prediction (SpliceAI max delta 0.01) suggests no splicing impact; REVEL and BayesDel are not applicable to this indel variant.³ TAF1 loss of function is an established disease mechanism (X-linked dystonia-parkinsonism via SVA retrotransposon insertion, and missense variants cause X-linked syndromic intellectual disability MRXS33); however, this variant is a missense change, not a null variant, so PVS1 does not apply. Overall, only one moderate pathogenic criterion (PM2) is met. Per generic ACMG/AMP 2015 combination rules, a single moderate criterion is insufficient for classification as likely pathogenic; the variant is classified as a Variant of Uncertain Significance (VUS).⁴