X-155022510-G-A

Variant names:

• chrX-155022510-G-A
• rs387906432
• NM_000132.4:c.43C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000132.4(F8):​c.43C>T​(p.Arg15*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: F8 NM_000132.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 0.456
• Publications: 1 publications found

Genes affected

F8 (HGNC:3546): (coagulation factor VIII) This gene encodes coagulation factor VIII, which participates in the intrinsic pathway of blood coagulation; factor VIII is a cofactor for factor IXa which, in the presence of Ca+2 and phospholipids, converts factor X to the activated form Xa. This gene produces two alternatively spliced transcripts. Transcript variant 1 encodes a large glycoprotein, isoform a, which circulates in plasma and associates with von Willebrand factor in a noncovalent complex. This protein undergoes multiple cleavage events. Transcript variant 2 encodes a putative small protein, isoform b, which consists primarily of the phospholipid binding domain of factor VIIIc. This binding domain is essential for coagulant activity. Defects in this gene results in hemophilia A, a common recessive X-linked coagulation disorder. [provided by RefSeq, Jul 2008]

F8 Gene-Disease associations (from GenCC):

• hemophilia A

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen
• mild hemophilia A

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• moderately severe hemophilia A

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• severe hemophilia A

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• symptomatic form of hemophilia A in female carriers

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 600 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-155022510-G-A is Pathogenic according to our data. Variant chrX-155022510-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 10152.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000132.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	F8	NM_000132.4	MANE Select	c.43C>T	p.Arg15*	stop_gained	Exon 1 of 26	NP_000123.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	F8	ENST00000360256.9	TSL:1 MANE Select	c.43C>T	p.Arg15*	stop_gained	Exon 1 of 26	ENSP00000353393.4
	F8	ENST00000647125.1		n.43C>T		non_coding_transcript_exon	Exon 1 of 14	ENSP00000496062.1
	F8	ENST00000423959.5	TSL:3	c.38+4270C>T		intron	N/A	ENSP00000409446.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 23

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000340

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary factor VIII deficiency disease Pathogenic:4

Jan 16, 2025

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

NM_000132.3(F8):c.43C>T(R15*) is a nonsense variant classified as pathogenic in the context of hemophilia A. R15* has been observed in cases with relevant disease (PMID: 39260745, 32026663, 20533009). Relevant functional assessments of this variant are not available in the literature. R15* has not been observed in referenced population frequency databases. In summary, NM_000132.3(F8):c.43C>T(R15*) is nonsense variant in a gene where loss of function is a known mechanism of disease, is predicted to disrupt protein function, and has been observed more frequently in cases with the relevant disease than in healthy populations. Please note: this variant was assessed in the context of healthy population screening.

Feb 23, 2023

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. This variant was predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported at least twice as pathogenic without evidence for the classification (ClinVar ID: VCV000010152 / PMID: 1979502). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline.

Apr 01, 1992

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

May 28, 2019

Mendelics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Pathogenic:1

Jun 22, 2022

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The F8 c.43C>T; p.Arg15Ter variant (rs387906432), also known as -5 in legacy nomenclature, is reported in the literature in individuals with severe hemophilia A (Bogdanova 2005, Feng 2021, Pattinson 1990). This variant is also reported in ClinVar (Variation ID: 10152). It is absent from the Genome Aggregation Database, indicating it is not a common polymorphism. This variant induces an early termination codon and is predicted to result in a truncated protein or mRNA subject to nonsense-mediated decay. Based on available information, this variant is considered to be pathogenic. References: Bogdanova N et al. Spectrum of molecular defects and mutation detection rate in patients with severe hemophilia A. Hum Mutat. 2005 Sep;26(3):249-54. PMID: 16086318. Feng Y et al. Mutation analysis in the F8 gene in 485 families with haemophilia A and prenatal diagnosis in China. Haemophilia. 2021 Jan;27(1):e88-e92. PMID: 33245802. Pattinson JK et al. The molecular genetic analysis of hemophilia A: a directed search strategy for the detection of point mutations in the human factor VIII gene. Blood. 1990 Dec 1;76(11):2242-8. PMID: 1979502.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Uncertain	0.040
CADD	Pathogenic	26
DANN	Uncertain	0.99
FATHMM_MKL	Benign	0.032	N
PhyloP100		0.46
Vest4		0.52
GERP RS		-1.4
PromoterAI		-0.039	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=5/195	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs387906432; hg19: chrX-154250785; COSMIC: COSV64270158; COSMIC: COSV64270158;