chr17-44377790-C-T

Variant names:

• chr17-44377790-C-T
• rs1555613626
• NM_000419.5:c.2095G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_000419.5(ITGA2B):​c.2095G>A​(p.Gly699Ser) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,459,254 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/24 in silico tools predict a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: ITGA2B NM_000419.5 missense, splice_region
• Scores: Splicing: ADA: 0.9991
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.25
• Publications: 0 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: ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• Glanzmann thrombasthenia

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

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics
• 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: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 73 curated pathogenic missense variants (we use a threshold of 10). The gene has 10 curated benign missense variants. Gene score misZ: 1.2307 (below the threshold of 3.09). Trascript score misZ: 1.3195 (below the threshold of 3.09). GenCC associations: The gene is linked to Glanzmann's thrombasthenia, autosomal dominant macrothrombocytopenia, platelet-type bleeding disorder 16, Glanzmann thrombasthenia 1, Glanzmann thrombasthenia.
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ITGA2B	NM_000419.5	c.2095G>A	p.Gly699Ser	missense_variant, splice_region_variant	Exon 21 of 30	ENST00000262407.6	NP_000410.2
ITGA2B	XM_011524749.2	c.2248G>A	p.Gly750Ser	missense_variant, splice_region_variant	Exon 21 of 29		XP_011523051.2
ITGA2B	XM_011524750.2	c.2248G>A	p.Gly750Ser	missense_variant, splice_region_variant	Exon 21 of 29		XP_011523052.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ITGA2B	ENST00000262407.6	c.2095G>A	p.Gly699Ser	missense_variant, splice_region_variant	Exon 21 of 30	1	NM_000419.5	ENSP00000262407.5
ITGA2B	ENST00000648408.1	c.1525G>A	p.Gly509Ser	missense_variant, splice_region_variant	Exon 17 of 25			ENSP00000498119.1
ITGA2B	ENST00000592462.5	n.890G>A		splice_region_variant, non_coding_transcript_exon_variant	Exon 10 of 15	5

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1459254 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726110

African (AFR) AF: 0.00 AC: 0 AN: 33414

American (AMR) AF: 0.00 AC: 0 AN: 44704

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26100

East Asian (EAS) AF: 0.00 AC: 0 AN: 39656

South Asian (SAS) AF: 0.00 AC: 0 AN: 86210

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53294

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5756

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1109820

Other (OTH) AF: 0.00 AC: 0 AN: 60300

GnomAD4 genome Cov.: 30

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Jan 19, 2017

Genetic Services Laboratory, University of Chicago

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.24	T
BayesDel_noAF	Benign	-0.58
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.053	T
Eigen	Benign	-0.097
Eigen_PC	Benign	0.072
FATHMM_MKL	Benign	0.74	D
LIST_S2	Benign	0.71	T
M_CAP	Benign	0.046	D
MetaRNN	Benign	0.18	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.1	L
PhyloP100		1.2
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-0.48	N
REVEL	Benign	0.023
Sift	Benign	0.12	T
Sift4G	Benign	0.34	T
Polyphen		0.15	B
Vest4		0.20
MutPred		0.41		Gain of MoRF binding (P = 0.1804);
MVP		0.59
MPC		0.63
ClinPred		0.76	D
GERP RS		4.4
Varity_R		0.32
gMVP		0.45
Mutation Taster		=68/32	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.83
SpliceAI score (max)		0.080		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: rs1555613626; hg19: chr17-42455158;