X-154928694-T-G

Position:

• chrX-154928694-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PM5 PP3 PP5_Moderate

The NM_000132.4(F8):​c.5096A>C​(p.Tyr1699Ser) variant causes a missense change. 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y1699C) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 23)
• Consequence: F8 NM_000132.4 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.25

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.828
• PP5: Variant X-154928694-T-G is Pathogenic according to our data. Variant chrX-154928694-T-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2713111.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
F8	NM_000132.4	c.5096A>C	p.Tyr1699Ser	missense_variant	14/26	ENST00000360256.9	NP_000123.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
F8	ENST00000360256.9	c.5096A>C	p.Tyr1699Ser	missense_variant	14/26	1	NM_000132.4	ENSP00000353393.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 23

Bravo AF: 0.0000302

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 25, 2023

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Tyr1699 amino acid residue in F8. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 2105906, 21909383, 24108539, 27629384). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt F8 protein function. This variant has not been reported in the literature in individuals affected with F8-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces tyrosine, which is neutral and polar, with serine, which is neutral and polar, at codon 1699 of the F8 protein (p.Tyr1699Ser). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.15
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.87	D
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Benign	0.79	T
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.83	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.1	M
PrimateAI	Uncertain	0.60	T
PROVEAN	Uncertain	-4.2	D
REVEL	Pathogenic	0.69
Sift	Uncertain	0.0070	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.55
MutPred		0.44		Loss of stability (P = 0.0205);
MVP		0.95
MPC		0.37
ClinPred		0.98	D
GERP RS		5.0
Varity_R		0.38
gMVP		0.98

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

Publications

LitVar

Other links and lift over

dbSNP: rs28935203; hg19: chrX-154156969;