rs75622274

Positions:

• chr17-44381058-A-C
• chr17-44381058-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_000419.5(ITGA2B):​c.1214T>G​(p.Ile405Ser) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,000 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ITGA2B NM_000419.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.06

Genes affected

ITGA2B (HGNC:6138): (integrin subunit alpha 2b) This gene encodes a member of the integrin alpha chain family of proteins. The encoded preproprotein is proteolytically processed to generate light and heavy chains that associate through disulfide linkages to form a subunit of the alpha-IIb/beta-3 integrin cell adhesion receptor. This receptor plays a crucial role in the blood coagulation system, by mediating platelet aggregation. Mutations in this gene are associated with platelet-type bleeding disorders, which are characterized by a failure of platelet aggregation, including Glanzmann thrombasthenia. [provided by RefSeq, Jan 2016]

ITGA2B (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ITGA2B	NM_000419.5	c.1214T>G	p.Ile405Ser	missense_variant	13/30	ENST00000262407.6	NP_000410.2
ITGA2B	XM_011524749.2	c.1367T>G	p.Ile456Ser	missense_variant	13/29		XP_011523051.2
ITGA2B	XM_011524750.2	c.1367T>G	p.Ile456Ser	missense_variant	13/29		XP_011523052.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ITGA2B	ENST00000262407.6	c.1214T>G	p.Ile405Ser	missense_variant	13/30	1	NM_000419.5	ENSP00000262407.5
ITGA2B	ENST00000648408.1	c.644T>G	p.Ile215Ser	missense_variant	9/25			ENSP00000498119.1
ITGA2B	ENST00000592226.5	n.454T>G		non_coding_transcript_exon_variant	7/10	5
ITGA2B	ENST00000592462.5	n.9T>G		non_coding_transcript_exon_variant	2/15	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000404 AC: 1 AN: 247548 Hom.: 0 AF XY: 0.00000744 AC XY: 1 AN XY: 134334

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000291

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461000 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726730

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Glanzmann thrombasthenia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 25, 2023

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on ITGA2B protein function. This variant has not been reported in the literature in individuals affected with ITGA2B-related conditions. This variant is present in population databases (rs75622274, gnomAD 0.003%). This sequence change replaces isoleucine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 405 of the ITGA2B protein (p.Ile405Ser). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.67
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.12
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.83	D
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.83	T
M_CAP	Uncertain	0.093	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Uncertain	0.41	D
MutationAssessor	Pathogenic	3.0	M
PrimateAI	Benign	0.29	T
PROVEAN	Pathogenic	-4.9	D
REVEL	Uncertain	0.57
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0010	D
Polyphen		0.96	D
Vest4		0.81
MutPred		0.89		Gain of disorder (P = 0.0028);
MVP		0.95
MPC		0.80
ClinPred		0.97	D
GERP RS		5.5
Varity_R		0.89
gMVP		0.92

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.15		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: rs75622274; hg19: chr17-42458426;