NM_021870.3:c.1320G>T

Variant names:

• chr4-154604876-C-A
• rs148378804
• NM_021870.3:c.1320G>T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_021870.3(FGG):​c.1320G>T​(p.Ala440Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,762 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. A440A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: FGG NM_021870.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.116
• Publications: 0 publications found

Genes affected

FGG (HGNC:3694): (fibrinogen gamma chain) The protein encoded by this gene is the gamma component of fibrinogen, a blood-borne glycoprotein comprised of three pairs of nonidentical polypeptide chains. Following vascular injury, fibrinogen is cleaved by thrombin to form fibrin which is the most abundant component of blood clots. In addition, various cleavage products of fibrinogen and fibrin regulate cell adhesion and spreading, display vasoconstrictor and chemotactic activities, and are mitogens for several cell types. Mutations in this gene lead to several disorders, including dysfibrinogenemia, hypofibrinogenemia and thrombophilia. Alternative splicing results in transcript variants encoding different isoforms. [provided by RefSeq, Aug 2015]

FGG Gene-Disease associations (from GenCC):

• congenital fibrinogen deficiency

  Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
• familial dysfibrinogenemia

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

  Inheritance: AD, AR Classification: STRONG Submitted by: Genomics England PanelApp
• congenital afibrinogenemia

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
• familial hypofibrinogenemia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.69).
• BP7: Synonymous conserved (PhyloP=-0.116 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_021870.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FGG	NM_021870.3	MANE Select	c.1320G>T	p.Ala440Ala	synonymous	Exon 9 of 9	NP_068656.2	P02679-1
	FGG	NM_000509.6		c.1299+21G>T		intron	N/A	NP_000500.2	P02679-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FGG	ENST00000336098.8	TSL:2 MANE Select	c.1320G>T	p.Ala440Ala	synonymous	Exon 9 of 9	ENSP00000336829.3	P02679-1
	FGG	ENST00000404648.7	TSL:1	c.1299+21G>T		intron	N/A	ENSP00000384860.3	P02679-2
	FGG	ENST00000407946.5	TSL:5	c.1344G>T	p.Ala448Ala	synonymous	Exon 9 of 9	ENSP00000384552.1	C9JC84

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461762 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727196

African (AFR) AF: 0.00 AC: 0 AN: 33466

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86248

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111928

Other (OTH) AF: 0.0000166 AC: 1 AN: 60392

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.69
CADD	Benign	0.99
DANN	Benign	0.37
PhyloP100		-0.12
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

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: rs148378804; hg19: chr4-155526028;