chr17-4933909-C-G

Variant names:

• chr17-4933909-C-G
• rs761456793
• NM_000173.7:c.1305C>G

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BP7

The NM_000173.7(GP1BA):​c.1305C>G​(p.Thr435Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. T435T) has been classified as Likely benign. The gene GP1BA is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: not found (cov: 0)
  • Exomes 𝑓: 0.0000037 (0 hom.)
• Consequence: GP1BA NM_000173.7 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.466
• Publications: 5 publications found

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]

CHRNE Gene-Disease associations (from GenCC):

• congenital myasthenic syndrome

  Inheritance: AR Classification: DEFINITIVE Submitted by: Illumina
• congenital myasthenic syndrome 4A

  Inheritance: AD, AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• congenital myasthenic syndrome 4B

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• congenital myasthenic syndrome 4C

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
• postsynaptic congenital myasthenic syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Specifications for GP1BA are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Likely_benign. The variant received -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.84).
• BP7: Synonymous conserved (PhyloP=-0.466 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000173.7. 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
	GP1BA	NM_000173.7	MANE Select	c.1305C>G	p.Thr435Thr	synonymous	Exon 2 of 2	NP_000164.5

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GP1BA	ENST00000329125.6	TSL:1 MANE Select	c.1305C>G	p.Thr435Thr	synonymous	Exon 2 of 2	ENSP00000329380.5	P07359
	CHRNE	ENST00000649830.1		c.-888+433G>C		intron	N/A	ENSP00000496907.1	A0A3B3IRM1

Frequencies

GnomAD3 genomes Cov.: 0

GnomAD2 exomes AF: 0.00000777 AC: 1 AN: 128696 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000439

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 0.00000366 AC: 2 AN: 546806 Hom.: 0 Cov.: 7 AF XY: 0.00000383 AC XY: 1 AN XY: 261432

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 14656

American (AMR) AF: 0.0000752 AC: 1 AN: 13294

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 9062

East Asian (EAS) AF: 0.00 AC: 0 AN: 3550

South Asian (SAS) AF: 0.00 AC: 0 AN: 18220

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 8116

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 1588

European-Non Finnish (NFE) AF: 0.00000217 AC: 1 AN: 460276

Other (OTH) AF: 0.00 AC: 0 AN: 18044

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.84
CADD	Benign	1.5
DANN	Benign	0.43
PhyloP100		-0.47

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

Other links and lift over

dbSNP: rs761456793; hg19: chr17-4837204;