chrX-154997095-C-A

Variant names:

• chrX-154997095-C-A
• rs137852380
• NM_000132.4:c.266G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP2 PP3

The NM_000132.4(F8):​c.266G>T​(p.Gly89Val) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G89D) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 23)
• Consequence: F8 NM_000132.4 missense, splice_region
• Scores: Splicing: ADA: 0.9989
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.47
• 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: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000132.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrX-154997095-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 10163.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 327 curated pathogenic missense variants (we use a threshold of 10). The gene has 28 curated benign missense variants. Gene score misZ: 2.4669 (below the threshold of 3.09). Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to hemophilia A, mild hemophilia A, symptomatic form of hemophilia A in female carriers, severe hemophilia A, moderately severe hemophilia A.
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.

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.266G>T	p.Gly89Val	missense splice_region	Exon 3 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.266G>T	p.Gly89Val	missense splice_region	Exon 3 of 26	ENSP00000353393.4
	F8	ENST00000423959.5	TSL:3	c.161G>T	p.Gly54Val	missense splice_region	Exon 3 of 6	ENSP00000409446.1
	F8	ENST00000453950.1	TSL:3	c.248G>T	p.Gly83Val	missense splice_region	Exon 4 of 5	ENSP00000389153.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 23

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.66	D
BayesDel_noAF	Pathogenic	0.71
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.89	D
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.7	H
PhyloP100		6.5
PrimateAI	Uncertain	0.60	T
PROVEAN	Pathogenic	-8.3	D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.89
MutPred		0.76		Loss of catalytic residue at M88 (P = 0.1769)
MVP		0.99
MPC		1.9
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.99
gMVP		1.0
Mutation Taster		=1/99	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		0.47		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.47		Position offset: 0

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs137852380; hg19: chrX-154225370;