rs74664206

Positions:

• chr17-44374352-A-C
• chr17-44374352-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_000419.5(ITGA2B):​c.3060+2T>G variant causes a splice donor change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ITGA2B NM_000419.5 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.05

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.03717949 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.5, offset of 5, new splice context is: gagGTgtga. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ITGA2B	NM_000419.5	c.3060+2T>G		splice_donor_variant		ENST00000262407.6	NP_000410.2
ITGA2B	XM_011524749.2	c.3111+2T>G		splice_donor_variant			XP_011523051.2
ITGA2B	XM_011524750.2	c.3096+307T>G		intron_variant			XP_011523052.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ITGA2B	ENST00000262407.6	c.3060+2T>G		splice_donor_variant		1	NM_000419.5	ENSP00000262407	P1
ITGA2B	ENST00000587295.5	c.253+1481T>G		intron_variant		3		ENSP00000467269
ITGA2B	ENST00000648408.1	c.2374+307T>G		intron_variant				ENSP00000498119
ITGA2B	ENST00000592462.5	n.2761T>G		non_coding_transcript_exon_variant	15/15	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	31
DANN	Uncertain	0.99
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Uncertain	0.81	D
MutationTaster	Benign	1.0	D;D
GERP RS		5.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		0.76		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.76		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs74664206; hg19: chr17-42451720;