rs28937285

Variant names:

• chrX-154931575-C-T
• rs28937285
• NM_000132.4:c.2215G>A

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PS3 PS4 PP3 PP1_Moderate PP4_Moderate PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The c.2215G>A (p.Glu739Lys) missense variant is absent from males in both gnomAD v2.1.1 and v3.1.1, meeting the PM2_Supporting criteria. The variant has a REVEL score of 0.614 (>0.6), meeting PP3 criteria. At least 13 patients with mild hemophilia A are reported in the literature and internal laboratory data meeting F8 phenotype criteria (PMID:24452774, 23711237, 21166991, 8547094, 16972227), which meets the PS4_Very strong and PP4_Moderate criteria. This variant has been labeled as an inverse discrepant variant, where the one-stage assays show lower factor VIII levels than the two-stage, or chromogenic, assays (EAHAD database; PMID:32232366). There were multiple related individuals across 6 different families reported that were genotyped, but their specific relation was not stated, so the PP1 was capped at the moderate weight to be conservative (PMID:24452774). In-vitro assays in COS-1 cells show FVIII-Glu739Lys results in lower FVIII:C in the mild range, as observed in patients with this variant and hemophilia A (PMID:30997536). In summary, this variant meets criteria to be classified as pathogenic. ACMG/AMP criteria applied, as specified by the Coagulation Factor Deficiency Variant Curation Expert Panel for F8: PS4_Very strong, PS3, PP1_Moderate, PP4_Moderate, PP3, PM2_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA255139/MONDO:0010602/071

• Frequency:
  • Genomes: 𝑓 0.000018 (0 hom., 0 hem., cov: 23)
  • Exomes 𝑓: 0.0000055 (0 hom. 3 hem.)
• Consequence: F8 NM_000132.4 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:4
• Conservation: PhyloP100: 2.71
• 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 14 ACMG points.

• PS3: For more information check the summary or visit ClinGen Evidence Repository.
• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PP1: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: For more information check the summary or visit ClinGen Evidence Repository.

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.2215G>A	p.Glu739Lys	missense	Exon 14 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.2215G>A	p.Glu739Lys	missense	Exon 14 of 26	ENSP00000353393.4
	F8	ENST00000647125.1		n.*1881G>A		non_coding_transcript_exon	Exon 14 of 14	ENSP00000496062.1
	F8	ENST00000647125.1		n.*1881G>A		3_prime_UTR	Exon 14 of 14	ENSP00000496062.1

Frequencies

GnomAD3 genomes AF: 0.0000179 AC: 2 AN: 111967 Hom.: 0 Cov.: 23

Gnomad AFR AF: 0.0000325

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000188

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 6 AN: 1097333 Hom.: 0 Cov.: 32 AF XY: 0.00000827 AC XY: 3 AN XY: 362753

African (AFR) AF: 0.00 AC: 0 AN: 26387

American (AMR) AF: 0.00 AC: 0 AN: 35177

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19370

East Asian (EAS) AF: 0.00 AC: 0 AN: 30201

South Asian (SAS) AF: 0.0000185 AC: 1 AN: 54090

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40518

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4132

European-Non Finnish (NFE) AF: 0.00000594 AC: 5 AN: 841393

Other (OTH) AF: 0.00 AC: 0 AN: 46065

GnomAD4 genome AF: 0.0000179 AC: 2 AN: 111967 Hom.: 0 Cov.: 23 AF XY: 0.00 AC XY: 0 AN XY: 34151

African (AFR) AF: 0.0000325 AC: 1 AN: 30759

American (AMR) AF: 0.00 AC: 0 AN: 10570

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 2645

East Asian (EAS) AF: 0.00 AC: 0 AN: 3588

South Asian (SAS) AF: 0.00 AC: 0 AN: 2709

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 6112

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 240

European-Non Finnish (NFE) AF: 0.0000188 AC: 1 AN: 53157

Other (OTH) AF: 0.00 AC: 0 AN: 1504

Alfa AF: 0.0000589 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
3	-	-	Hereditary factor VIII deficiency disease (3)
1	-	-	F8-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Benign	17
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.68	D
FATHMM_MKL	Benign	0.24	N
LIST_S2	Benign	0.79	T
M_CAP	Pathogenic	0.42	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Uncertain	0.44	D
MutationAssessor	Benign	1.5	L
PhyloP100		2.7
PrimateAI	Benign	0.40	T
PROVEAN	Benign	-2.3	N
REVEL	Uncertain	0.61
Sift	Uncertain	0.022	D
Sift4G	Benign	0.18	T
Polyphen		0.91	P
Vest4		0.65
MutPred		0.81		Gain of ubiquitination at E739 (P = 0.0109)
MVP		1.0
MPC		0.082
ClinPred		0.67	D
GERP RS		5.2
Varity_R		0.46
gMVP		0.95
Mutation Taster		=28/72	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: rs28937285; hg19: chrX-154159850;