4-154584450-C-T

Variant names:

• chr4-154584450-C-T
• NM_000508.5:c.2275G>A

Variant summary

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

The NM_000508.5(FGA):​c.2275G>A​(p.Glu759Lys) variant causes a missense 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. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: FGA NM_000508.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.385
• Publications: 0 publications found

Genes affected

FGA (HGNC:3661): (fibrinogen alpha chain) This gene encodes the alpha subunit of the coagulation factor fibrinogen, which is a component of the blood clot. Following vascular injury, the encoded preproprotein is proteolytically processed by thrombin during the conversion of fibrinogen to fibrin. Mutations in this gene lead to several disorders, including dysfibrinogenemia, hypofibrinogenemia, afibrinogenemia and renal amyloidosis. Alternative splicing results in multiple transcript variants, at least one of which encodes an isoform that undergoes proteolytic processing. [provided by RefSeq, Jan 2016]

FGA Gene-Disease associations (from GenCC):

• familial dysfibrinogenemia

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• congenital afibrinogenemia

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• congenital fibrinogen deficiency

  Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
• familial visceral amyloidosis

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• thrombophilia

  Inheritance: AR, AD Classification: STRONG Submitted by: Genomics England PanelApp
• AFib amyloidosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial hypofibrinogenemia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

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 (MetaRNN=0.22757292).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FGA	NM_000508.5	c.2275G>A	p.Glu759Lys	missense_variant	Exon 6 of 6		NP_000499.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FGA	ENST00000651975.2	c.2275G>A	p.Glu759Lys	missense_variant	Exon 6 of 6			ENSP00000498441.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Nov 08, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2275G>A (p.E759K) alteration is located in exon 6 (coding exon 6) of the FGA gene. This alteration results from a G to A substitution at nucleotide position 2275, causing the glutamic acid (E) at amino acid position 759 to be replaced by a lysine (K). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.064
BayesDel_addAF	Benign	-0.052	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	0.61
DANN	Benign	0.95
DEOGEN2	Benign	0.085	T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.17	N
LIST_S2	Uncertain	0.89	D
M_CAP	Benign	0.059	D
MetaRNN	Benign	0.23	T
MetaSVM	Uncertain	0.097	D
MutationAssessor	Benign	0.83	L
PhyloP100		-0.39
PrimateAI	Benign	0.21	T
PROVEAN	Benign	-1.2	N
REVEL	Benign	0.21
Sift	Benign	0.31	T
Sift4G	Benign	0.49	T
Polyphen		0.099	B
Vest4		0.054
MutPred		0.49		Gain of ubiquitination at E759 (P = 0.0051);
MVP		0.89
MPC		0.078
ClinPred		0.27	T
GERP RS		-4.4
Varity_R		0.17
gMVP		0.50
Mutation Taster		=82/18	polymorphism

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

hg19: chr4-155505602;