chrX-139537138-G-T

Variant names:

• chrX-139537138-G-T
• rs137852225
• NM_000133.4:c.217G>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_000133.4(F9):​c.217G>T​(p.Glu73*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 23)
• Consequence: F9 NM_000133.4 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.13
• Publications: 3 publications found

Genes affected

F9 (HGNC:3551): (coagulation factor IX) This gene encodes vitamin K-dependent coagulation factor IX that circulates in the blood as an inactive zymogen. This factor is converted to an active form by factor XIa, which excises the activation peptide and thus generates a heavy chain and a light chain held together by one or more disulfide bonds. The role of this activated factor IX in the blood coagulation cascade is to activate factor X to its active form through interactions with Ca+2 ions, membrane phospholipids, and factor VIII. Alterations of this gene, including point mutations, insertions and deletions, cause factor IX deficiency, which is a recessive X-linked disorder, also called hemophilia B or Christmas disease. Alternative splicing results in multiple transcript variants encoding different isoforms that may undergo similar proteolytic processing. [provided by RefSeq, Sep 2015]

F9 Gene-Disease associations (from GenCC):

• hemophilia B

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen
• mild hemophilia B

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• moderately severe hemophilia B

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• severe hemophilia B

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• symptomatic form of hemophilia B in female carriers

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• thrombophilia, X-linked, due to factor 9 defect

  Inheritance: XL Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 10 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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000133.4. 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
	F9	NM_000133.4	MANE Select	c.217G>T	p.Glu73*	stop_gained	Exon 2 of 8	NP_000124.1
	F9	NM_001313913.2		c.217G>T	p.Glu73*	stop_gained	Exon 2 of 7	NP_001300842.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	F9	ENST00000218099.7	TSL:1 MANE Select	c.217G>T	p.Glu73*	stop_gained	Exon 2 of 8	ENSP00000218099.2
	F9	ENST00000394090.2	TSL:1	c.217G>T	p.Glu73*	stop_gained	Exon 2 of 7	ENSP00000377650.2
	F9	ENST00000479617.2	TSL:5	n.224G>T		non_coding_transcript_exon	Exon 2 of 4

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
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	38
DANN	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		9.1
Vest4		0.90
GERP RS		5.2
Mutation Taster		=0/200	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.10		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: rs137852225; hg19: chrX-138619297;