chrX-139541073-A-C

Variant names:

• chrX-139541073-A-C
• rs398122990
• NM_000133.4:c.278-3A>C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000133.4(F9):​c.278-3A>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 23)
• Consequence: F9 NM_000133.4 splice_region, intron
• Scores: Splicing: ADA: 0.002689
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.53
• Publications: 1 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: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.39).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
F9	NM_000133.4	c.278-3A>C		splice_region_variant, intron_variant	Intron 3 of 7	ENST00000218099.7	NP_000124.1
F9	NM_001313913.2	c.277+3687A>C		intron_variant	Intron 3 of 6		NP_001300842.1
F9	XM_005262397.5	c.278-3A>C		splice_region_variant, intron_variant	Intron 3 of 6		XP_005262454.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
F9	ENST00000218099.7	c.278-3A>C		splice_region_variant, intron_variant	Intron 3 of 7	1	NM_000133.4	ENSP00000218099.2
F9	ENST00000394090.2	c.277+3687A>C		intron_variant	Intron 3 of 6	1		ENSP00000377650.2
F9	ENST00000479617.2	n.242-14A>C		intron_variant	Intron 2 of 3	5

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 26

GnomAD4 genome Cov.: 23

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.39
CADD	Benign	15
DANN	Benign	0.87
PhyloP100		1.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0027
dbscSNV1_RF	Benign	0.098
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: rs398122990; hg19: chrX-138623232;