17-4932764-CTGAG-C

Position:

• chr17-4932764-CTGAG-C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000173.7(GP1BA):​c.165_168del​(p.Ser55ArgfsTer12) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GP1BA NM_000173.7 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.65

Genes affected

GP1BA (HGNC:4439): (glycoprotein Ib platelet subunit alpha) Glycoprotein Ib (GP Ib) is a platelet surface membrane glycoprotein composed of a heterodimer, an alpha chain and a beta chain, that is linked by disulfide bonds. The Gp Ib functions as a receptor for von Willebrand factor (VWF). The complete receptor complex includes noncovalent association of the alpha and beta subunits with platelet glycoprotein IX and platelet glycoprotein V. The binding of the GP Ib-IX-V complex to VWF facilitates initial platelet adhesion to vascular subendothelium after vascular injury, and also initiates signaling events within the platelet that lead to enhanced platelet activation, thrombosis, and hemostasis. This gene encodes the alpha subunit. Mutations in this gene result in Bernard-Soulier syndromes and platelet-type von Willebrand disease. The coding region of this gene is known to contain a polymophic variable number tandem repeat (VNTR) domain that is associated with susceptibility to nonarteritic anterior ischemic optic neuropathy. [provided by RefSeq, Oct 2013]

CHRNE (HGNC:1966): (cholinergic receptor nicotinic epsilon subunit) Acetylcholine receptors at mature mammalian neuromuscular junctions are pentameric protein complexes composed of four subunits in the ratio of two alpha subunits to one beta, one epsilon, and one delta subunit. The acetylcholine receptor changes subunit composition shortly after birth when the epsilon subunit replaces the gamma subunit seen in embryonic receptors. Mutations in the epsilon subunit are associated with congenital myasthenic syndrome. [provided by RefSeq, Sep 2009]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 40 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-4932764-CTGAG-C is Pathogenic according to our data. Variant chr17-4932764-CTGAG-C is described in ClinVar as [Pathogenic]. Clinvar id is 2736403.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr17-4932764-CTGAG-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GP1BA	NM_000173.7	c.165_168del	p.Ser55ArgfsTer12	frameshift_variant	2/2	ENST00000329125.6	NP_000164.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GP1BA	ENST00000329125.6	c.165_168del	p.Ser55ArgfsTer12	frameshift_variant	2/2	1	NM_000173.7	ENSP00000329380	P1
CHRNE	ENST00000649830.1	c.-888+1574_-888+1577del		intron_variant				ENSP00000496907

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 03, 2023

Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. This sequence change creates a premature translational stop signal (p.Ser55Argfs*12) in the GP1BA gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 598 amino acid(s) of the GP1BA protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individuals with Bernard-Soulier syndrome (PMID: 11054083, 18791947). This variant is also known as p.Ser39fs. Experimental studies have shown that this premature translational stop signal affects GP1BA function (PMID: 11054083). This variant disrupts a region of the GP1BA protein in which other variant(s) (p.Trp540*) have been determined to be pathogenic (PMID: 9233564, 9639514). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr17-4836059;