X-154928964-GT-GTT

Variant names:

• chrX-154928964-G-GT
• rs397514036
• NM_000132.4:c.4825dupA

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.4825dupA​(p.Thr1609AsnfsTer4) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 23)
• Consequence: F8 NM_000132.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 1.59
• Publications: 4 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 undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-154928964-G-GT is Pathogenic according to our data. Variant chrX-154928964-G-GT is described in CliVar as Pathogenic. Clinvar id is 10263.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chrX-154928964-G-GT is described in CliVar as Pathogenic. Clinvar id is 10263.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
F8	NM_000132.4	c.4825dupA	p.Thr1609AsnfsTer4	frameshift_variant	Exon 14 of 26	ENST00000360256.9	NP_000123.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
F8	ENST00000360256.9	c.4825dupA	p.Thr1609AsnfsTer4	frameshift_variant	Exon 14 of 26	1	NM_000132.4	ENSP00000353393.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 23

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.000106

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary factor VIII deficiency disease Pathogenic:2

Dec 01, 1993

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Jun 18, 2025

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: F8 c.4825dupA (p.Thr1609AsnfsX4) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant was absent in 182603 control chromosomes (gnomAD). c.4825dupA has been observed in multiple individuals affected with Factor VIII Deficiency (Hemophilia A) (Lu_2018). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 29381227). ClinVar contains an entry for this variant (Variation ID: 10263). Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:1

Jun 01, 2022

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The F8 c.4825dupA; p.Thr1609AsnfsTer4 variant (rs397514036) is reported in the literature in multiple individuals affected with severe hemophilia A (Lu 2018, Factor VIII database and references therein). In at least one affected individual, this variant is reported to have arisen de novo (Lu 2018). This variant is absent from general population databases (Exome Variant Server, Genome Aggregation Database), indicating it is not a common polymorphism. This variant causes a frameshift by inserting a single nucleotide, so it 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: Factor VIII variant database: https://f8-db.eahad.org/ Lu Y et al. Spectrum and origin of mutations in sporadic cases of haemophilia A in China. Haemophilia. 2018 Mar;24(2):291-298. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.6
Mutation Taster		=0/200	disease causing (ClinVar)

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: rs397514036; hg19: chrX-154157239; COSMIC: COSV64269532; COSMIC: COSV64269532;