rs149606847

Positions:

• chr6-33305267-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_003190.5(TAPBP):​c.590C>T​(p.Pro197Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000416 in 1,601,276 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00043 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00041 (1 hom.)
• Consequence: TAPBP NM_003190.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.602

Genes affected

TAPBP (HGNC:11566): (TAP binding protein) This gene encodes a transmembrane glycoprotein which mediates interaction between newly assembled major histocompatibility complex (MHC) class I molecules and the transporter associated with antigen processing (TAP), which is required for the transport of antigenic peptides across the endoplasmic reticulum membrane. This interaction is essential for optimal peptide loading on the MHC class I molecule. Up to four complexes of MHC class I and this protein may be bound to a single TAP molecule. This protein contains a C-terminal double-lysine motif (KKKAE) known to maintain membrane proteins in the endoplasmic reticulum. This gene lies within the major histocompatibility complex on chromosome 6. Alternative splicing results in three transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.024279952).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TAPBP	NM_003190.5	c.590C>T	p.Pro197Leu	missense_variant	4/8	ENST00000434618.7	NP_003181.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TAPBP	ENST00000434618.7	c.590C>T	p.Pro197Leu	missense_variant	4/8	1	NM_003190.5	ENSP00000395701	P2

Frequencies

GnomAD3 genomes AF: 0.000427 AC: 65 AN: 152124 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000217

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.000188

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000735

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000350 AC: 84 AN: 239958 Hom.: 0 AF XY: 0.000346 AC XY: 45 AN XY: 130032

Gnomad AFR exome AF: 0.000191

Gnomad AMR exome AF: 0.000272

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000478

Gnomad NFE exome AF: 0.000636

Gnomad OTH exome AF: 0.000345

GnomAD4 exome AF: 0.000415 AC: 601 AN: 1449036 Hom.: 1 Cov.: 34 AF XY: 0.000399 AC XY: 287 AN XY: 719720

Gnomad4 AFR exome AF: 0.0000909

Gnomad4 AMR exome AF: 0.000300

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000758

Gnomad4 SAS exome AF: 0.0000118

Gnomad4 FIN exome AF: 0.0000755

Gnomad4 NFE exome AF: 0.000511

Gnomad4 OTH exome AF: 0.000218

GnomAD4 genome AF: 0.000427 AC: 65 AN: 152240 Hom.: 0 Cov.: 32 AF XY: 0.000417 AC XY: 31 AN XY: 74424

Gnomad4 AFR AF: 0.000217

Gnomad4 AMR AF: 0.000196

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000194

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.000188

Gnomad4 NFE AF: 0.000735

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000496 Hom.: 0

Bravo AF: 0.000461

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.000519 AC: 2

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00116 AC: 10

ExAC AF: 0.000346 AC: 42

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

MHC class I deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 22, 2024

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 197 of the TAPBP protein (p.Pro197Leu). This variant is present in population databases (rs149606847, gnomAD 0.06%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with TAPBP-related conditions. ClinVar contains an entry for this variant (Variation ID: 574706). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The leucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.067
BayesDel_addAF	Benign	-0.49	T
BayesDel_noAF	Benign	-0.57
CADD	Benign	12
DANN	Benign	0.59
DEOGEN2	Benign	0.057	.;T;.;T;.
Eigen	Benign	-1.0
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.054	N
LIST_S2	Benign	0.71	T;T;T;T;T
M_CAP	Benign	0.0038	T
MetaRNN	Benign	0.024	T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	1.0	N;N;N;N;N
PrimateAI	Benign	0.33	T
PROVEAN	Uncertain	-3.1	D;D;D;D;D
REVEL	Benign	0.033
Sift	Benign	0.19	T;T;D;T;T
Sift4G	Benign	0.26	T;T;T;T;.
Polyphen		0.0010	.;B;.;.;.
Vest4		0.10
MVP		0.21
MPC		0.35
ClinPred		0.0086	T
GERP RS		1.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
gMVP		0.25

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs149606847; hg19: chr6-33273044;