Is TAPBP p.Ala191= (c.573C>T) pathogenic?

TAPBP p.Ala191= (c.573C>T) is classified Benign/Likely benign in TAPBP (ClinVar, Multiple submitters, 3 submitters; last evaluated 2026-01-23). Rare (popmax 0.786%, afr); Associated with MHC class I deficiency.

What condition is associated with TAPBP p.Ala191= (c.573C>T)?

TAPBP p.Ala191= (c.573C>T) is associated with MHC class I deficiency (ClinVar).

How common is TAPBP p.Ala191= (c.573C>T) in the general population?

TAPBP p.Ala191= (c.573C>T) is rare (popmax 0.786%, afr) (gnomAD).

TAPBP p.Ala191=

Q: How is Immunodeficiency by defective expression of MHC class I inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

c.573C>T · rs34349100 · VCV534725

Benign/Likely benign Multiple submitters

Classification

Benign/Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

gnomAD v4.1

Rare

rare (popmax 0.786%, afr)

Conditions

MHC class I deficiency

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -1.1	GERP -3.1
Overall
CADD	6.712	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.786% African / African-American · 583/74,218 alleles

Filtering AF 0.733% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.712%

Overall 0.0392% 623/1,588,184 alleles · rare exomes 302/1,435,930 · genomes 321/152,254 · joint denominator

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.786%	127
Remaining individualsnot grpmax-eligible	0.031%	3,228
Admixed American	0.014%	7,139
South Asian	0.0046%	21,762
European (non-Finnish)	0.000772%	129,609

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: TAPBP
Protein: p.Ala191=
Coding: c.573C>T
MANE Select: NM_003190
dbSNP: rs34349100
Type: single nucleotide variant
Location: chr6:33305284 (GRCh38)
Gene constraint: LOEUF 1.061 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 87.71 · 12 PDB
Residue 191: an α-helix

Full TAPBP gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

MHC class I deficiency — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Immunodeficiency by defective expression of MHC class I (Orphanet):

Inheritance: Autosomal recessive
Onset: Childhood

Similar variants

TAPBP p.Ala191Thr Uncertain significance ★★ ⚠ same residue
TAPBP p.Ala220Val Uncertain significance ★★ ⚠ same condition
TAPBP p.Ala305Ser Uncertain significance ★★ ⚠ same condition
TAPBP p.Ala305Thr Uncertain significance ★★ ⚠ same condition
TAPBP p.Ala309Glu Uncertain significance ★★ ⚠ same condition
TAPBP p.Ala396Thr Uncertain significance ★★ ⚠ same condition
TAPBP p.Ala433Thr Uncertain significance ★★ ⚠ same condition
TAPBP p.Arg208Cys Uncertain significance ★★ ⚠ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/tapbp-p-ala191 (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown