17-4932748-C-G

Variant names:

• chr17-4932748-C-G
• rs1043841849
• NM_000173.7:c.144C>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000173.7(GP1BA):​c.144C>G​(p.Asp48Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,698 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GP1BA NM_000173.7 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0790
• Publications: 0 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: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia
• congenital myasthenic syndrome 4B

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia
• 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

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.113021374).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GP1BA	NM_000173.7	c.144C>G	p.Asp48Glu	missense_variant	Exon 2 of 2	ENST00000329125.6	NP_000164.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GP1BA	ENST00000329125.6	c.144C>G	p.Asp48Glu	missense_variant	Exon 2 of 2	1	NM_000173.7	ENSP00000329380.5
CHRNE	ENST00000649830.1	c.-888+1594G>C		intron_variant	Intron 1 of 10			ENSP00000496907.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461698 Hom.: 0 Cov.: 37 AF XY: 0.00000138 AC XY: 1 AN XY: 727138

African (AFR) AF: 0.0000597 AC: 2 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53398

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111862

Other (OTH) AF: 0.00 AC: 0 AN: 60374

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Apr 22, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GP1BA c.144C>G (p.Asp48Glu) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-06 in 1607052 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.144C>G in individuals affected with Bernard-Soulier Syndrome, Type A2, Autosomal Dominant and no experimental evidence demonstrating its impact on protein function have been reported. No submitters have cited clinical-significance assessments for this variant to ClinVar. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.23
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.70
CADD	Benign	0.28
DANN	Benign	0.89
DEOGEN2	Uncertain	0.47	T;T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.18	N
LIST_S2	Benign	0.54	T;T
M_CAP	Benign	0.023	T
MetaRNN	Benign	0.11	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.6	L;.
PhyloP100		-0.079
PrimateAI	Benign	0.32	T
PROVEAN	Benign	-2.1	N;.
REVEL	Benign	0.011
Sift	Benign	0.047	D;.
Sift4G	Benign	0.14	T;T
Vest4		0.040
MutPred		0.27		Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);
MVP		0.52
MPC		0.37
ClinPred		0.12	T
GERP RS		-1.2
PromoterAI		-0.0032	Neutral
Varity_R		0.28
gMVP		0.39
Mutation Taster		=96/4	polymorphism

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: rs1043841849; hg19: chr17-4836043;