chrX-154836181-C-A

Variant names:

• chrX-154836181-C-A
• rs186338743
• NM_000132.4:c.*1416G>T

Variant summary

Our verdict is Benign. The variant received -11 ACMG points: 0P and 11B. BP4_Strong BP6_Moderate BS1 BS2_Supporting

The NM_000132.4(F8):​c.*1416G>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000161 in 111,858 control chromosomes in the GnomAD database, including 1 homozygotes. There are 9 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★).

• Frequency:
  • Genomes: 𝑓 0.00016 (1 hom., 9 hem., cov: 23)
  • Failed GnomAD Quality Control
• Consequence: F8 NM_000132.4 3_prime_UTR
• Clinical Significance: Benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -1.24
• Publications: 0 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: Benign. The variant received -11 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.74).
• BP6: Variant X-154836181-C-A is Benign according to our data. Variant chrX-154836181-C-A is described in ClinVar as [Benign]. Clinvar id is 368106.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS1: Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.000161 (18/111858) while in subpopulation SAS AF = 0.00523 (14/2678). AF 95% confidence interval is 0.00316. There are 1 homozygotes in GnomAd4. There are 9 alleles in the male GnomAd4 subpopulation. Median coverage is 23. This position passed quality control check.
• BS2: High Hemizygotes in GnomAd4 at 9 XL geneVariant has number of hemizygotes lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
F8	NM_000132.4	c.*1416G>T		3_prime_UTR_variant	Exon 26 of 26	ENST00000360256.9	NP_000123.1
F8	NM_019863.3	c.*1416G>T		3_prime_UTR_variant	Exon 5 of 5		NP_063916.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
F8	ENST00000360256.9	c.*1416G>T		3_prime_UTR_variant	Exon 26 of 26	1	NM_000132.4	ENSP00000353393.4
F8	ENST00000330287.10	c.*1416G>T		3_prime_UTR_variant	Exon 5 of 5	1		ENSP00000327895.6
F8	ENST00000644698.1	c.*1416G>T		3_prime_UTR_variant	Exon 6 of 6			ENSP00000495706.1

Frequencies

GnomAD3 genomes AF: 0.000161 AC: 18 AN: 111805 Hom.: 1 Cov.: 23

Gnomad AFR AF: 0.0000325

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000951

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00521

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000376

Gnomad OTH AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AC0 AC: 0 AN: 0 Hom.: 0 Cov.: 0 AC XY: 0 AN XY: 0

African (AFR) AC: 0 AN: 0

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AC: 0 AN: 0

South Asian (SAS) AC: 0 AN: 0

European-Finnish (FIN) AC: 0 AN: 0

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AC: 0 AN: 0

Other (OTH) AC: 0 AN: 0

GnomAD4 genome AF: 0.000161 AC: 18 AN: 111858 Hom.: 1 Cov.: 23 AF XY: 0.000264 AC XY: 9 AN XY: 34034

African (AFR) AF: 0.0000325 AC: 1 AN: 30790

American (AMR) AF: 0.0000949 AC: 1 AN: 10532

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 2644

East Asian (EAS) AF: 0.00 AC: 0 AN: 3576

South Asian (SAS) AF: 0.00523 AC: 14 AN: 2678

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 6032

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 215

European-Non Finnish (NFE) AF: 0.0000376 AC: 2 AN: 53178

Other (OTH) AF: 0.00 AC: 0 AN: 1527

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000227

ClinVar

Significance: Benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary factor VIII deficiency disease Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.74
CADD	Benign	0.29
DANN	Benign	0.83
PhyloP100		-1.2

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: rs186338743; hg19: chrX-154064456;