17-44372407-C-T

Variant names:

• chr17-44372407-C-T
• rs879255514
• NM_000419.5:c.3077G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM3 PP3 PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The NM_000419.5:c.3077G>A variant results in the Arg1026Gln missense change. It is absent in population databases, including gnomADv2.1.1 (PM2_supporting), and is predicted damaging by in silico tools (REVEL score of 0.904; PP3). One compound heterozygous individual with mild bleeding, thrombocytopenia and platelet anisotrpy is reported in the literature several times (PMID:25728920) with confirmation of c.1440-13_1440-1del (classified Pathogenic by the PD VCEP; PM3) in trans. The variant results in reduced expression of the αIIbβ3 complex on platelet surface. The expressed αIIbβ3 was not constitutively active and were able to bind fibrinogen only upon activation by anti-LIBS antibody. In summary, this variant meets the criteria to be classified as uncertain significance for autosomal recessive Glanzmann Thrombasthenia based on the ACMG/AMP criteria applied, as specified by the ClinGen PD VCEP: PM2_Supporting, PM3, PP3 (PD VCEP specifications version 2.1). LINK:https://erepo.genome.network/evrepo/ui/classification/CA10575572/MONDO:0010119/011

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: ITGA2B NM_000419.5 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:2 U:3
• Conservation: PhyloP100: 4.08
• Publications: 4 publications found

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 Gene-Disease associations (from GenCC):

• platelet-type bleeding disorder 16

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen
• Glanzmann thrombasthenia

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Glanzmann's thrombasthenia

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet
• Glanzmann thrombasthenia 1

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• autosomal dominant macrothrombocytopenia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM3: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000419.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ITGA2B	NM_000419.5	MANE Select	c.3077G>A	p.Arg1026Gln	missense	Exon 30 of 30	NP_000410.2	P08514-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ITGA2B	ENST00000262407.6	TSL:1 MANE Select	c.3077G>A	p.Arg1026Gln	missense	Exon 30 of 30	ENSP00000262407.5	P08514-1
	ITGA2B	ENST00000901307.1		c.2963G>A	p.Arg988Gln	missense	Exon 29 of 29	ENSP00000571366.1
	ITGA2B	ENST00000949677.1		c.2960G>A	p.Arg987Gln	missense	Exon 29 of 29	ENSP00000619736.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251278 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461860 Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4 AN XY: 727228

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000899 AC: 10 AN: 1111998

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
2	-	-	Platelet-type bleeding disorder 16 (2)
-	1	-	Glanzmann thrombasthenia (1)
-	1	-	not specified (1)
-	1	-	Thrombocytopenia (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.50
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.86	D
Eigen	Pathogenic	0.77
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.88	D
M_CAP	Pathogenic	0.68	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.88	D
MutationAssessor	Pathogenic	3.4	M
PhyloP100		4.1
PrimateAI	Benign	0.46	T
PROVEAN	Uncertain	-3.3	D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.95
MutPred		0.96		Loss of MoRF binding (P = 0.0901)
MVP		0.92
MPC		1.1
ClinPred		1.0	D
GERP RS		4.5
Varity_R		0.96
gMVP		0.84
Mutation Taster		=32/68	disease causing

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

Other links and lift over

dbSNP: rs879255514; hg19: chr17-42449775;