NM_000371.4:c.13C>G

Variant names:

• chr18-31591915-C-G
• rs144792001
• NM_000371.4:c.13C>G

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_000371.4(TTR):​c.13C>G​(p.Arg5Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,872 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R5H) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: TTR NM_000371.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.796
• Publications: 2 publications found

Genes affected

TTR (HGNC:12405): (transthyretin) This gene encodes one of the three prealbumins, which include alpha-1-antitrypsin, transthyretin and orosomucoid. The encoded protein, transthyretin, is a homo-tetrameric carrier protein, which transports thyroid hormones in the plasma and cerebrospinal fluid. It is also involved in the transport of retinol (vitamin A) in the plasma by associating with retinol-binding protein. The protein may also be involved in other intracellular processes including proteolysis, nerve regeneration, autophagy and glucose homeostasis. Mutations in this gene are associated with amyloid deposition, predominantly affecting peripheral nerves or the heart, while a small percentage of the gene mutations are non-amyloidogenic. The mutations are implicated in the etiology of several diseases, including amyloidotic polyneuropathy, euthyroid hyperthyroxinaemia, amyloidotic vitreous opacities, cardiomyopathy, oculoleptomeningeal amyloidosis, meningocerebrovascular amyloidosis and carpal tunnel syndrome. [provided by RefSeq, Aug 2017]

TTR Gene-Disease associations (from GenCC):

• amyloidosis, hereditary systemic 1

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• familial amyloid neuropathy

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Orphanet
• hereditary ATTR amyloidosis

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• heart conduction disease

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• ATTRV122I amyloidosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 108 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Gene score misZ: 1.0149 (below the threshold of 3.09). Trascript score misZ: 1.5458 (below the threshold of 3.09). GenCC associations: The gene is linked to familial amyloid neuropathy, amyloidosis, hereditary systemic 1, ATTRV122I amyloidosis, hereditary ATTR amyloidosis, heart conduction disease.
• BP4: Computational evidence support a benign effect (MetaRNN=0.123251796).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000371.4. 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
	TTR	NM_000371.4	MANE Select	c.13C>G	p.Arg5Gly	missense	Exon 1 of 4	NP_000362.1	P02766

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTR	ENST00000237014.8	TSL:1 MANE Select	c.13C>G	p.Arg5Gly	missense	Exon 1 of 4	ENSP00000237014.4	P02766
	TTR	ENST00000649620.1		c.13C>G	p.Arg5Gly	missense	Exon 3 of 6	ENSP00000497927.1	P02766
	TTR	ENST00000858988.1		c.13C>G	p.Arg5Gly	missense	Exon 3 of 6	ENSP00000529047.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461872 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 727234

African (AFR) AF: 0.00 AC: 0 AN: 33480

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

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1112002

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Amyloidosis, hereditary systemic 1 (1)
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Uncertain	0.053	T
BayesDel_noAF	Benign	-0.16
CADD	Benign	13
DANN	Benign	0.91
DEOGEN2	Benign	0.32	T
Eigen	Benign	-0.85
Eigen_PC	Benign	-0.89
FATHMM_MKL	Benign	0.12	N
LIST_S2	Benign	0.56	T
M_CAP	Benign	0.052	D
MetaRNN	Benign	0.12	T
MetaSVM	Uncertain	-0.17	T
MutationAssessor	Benign	1.7	L
PhyloP100		0.80
PrimateAI	Benign	0.20	T
PROVEAN	Benign	-0.82	N
REVEL	Uncertain	0.32
Sift	Benign	0.12	T
Sift4G	Benign	0.13	T
Polyphen		0.12	B
Vest4		0.10
MutPred		0.39		Gain of catalytic residue at R5 (P = 0.0419)
MVP		0.86
MPC		0.60
ClinPred		0.050	T
GERP RS		1.4
PromoterAI		-0.20	Neutral
Varity_R		0.082
gMVP		0.80
Mutation Taster		=94/6	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

dbSNP: rs144792001; hg19: chr18-29171878;