rs121918092

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B.

PM1PM5PP2BS2_Supporting

The NM_000371.4(TTR):c.386C>T(p.Ala129Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,614,066 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. A129S) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

TTR
NM_000371.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5O:1

Conservation

PhyloP100: 2.42

Publications

5 publications found

Variant links:

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: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
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

TTR links:

ENSG00000294516 (HGNC:):

ENSG00000294516 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM1

In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 9 uncertain in NM_000371.4

PM5

Other missense variant is known to change same aminoacid residue: Variant chr18-31598616-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 626843.We mark this variant Likely_pathogenic, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

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.

BS2

High AC in GnomAd4 at 5 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTR	NM_000371.4 link	c.386C>T	p.Ala129Val	missense_variant	Exon 4 of 4	ENST00000237014.8	NP_000362.1	P02766E9KL36
LOC124904277	XR_007066326.1 link	n.129-2922G>A		intron_variant	Intron 1 of 1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
TTR	ENST00000237014.8 link	c.386C>T	p.Ala129Val	missense_variant	Exon 4 of 4	1	NM_000371.4	ENSP00000237014.4	P02766
TTR	ENST00000649620.1 link	c.386C>T	p.Ala129Val	missense_variant	Exon 6 of 6			ENSP00000497927.1	P02766
TTR	ENST00000610404.5 link	c.290C>T	p.Ala97Val	missense_variant	Exon 4 of 4	5		ENSP00000477599.2	A0A087WT59
ENSG00000294516	ENST00000724044.1 link	n.286-2922G>A		intron_variant	Intron 2 of 2

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152194

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.0000159

AC:

AN:

251442

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.00000958

AC:

AN:

1461872

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727238

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53400

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000108

AC:

AN:

1112012

Other (OTH)

AF:

0.0000166

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.468

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152194

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74352

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41454

American (AMR)

AF:

0.000131

AC:

AN:

15290

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10618

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68018

Other (OTH)

AF:

0.000478

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.565

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000467

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Apr 22, 2020

Mayo Clinic Laboratories, Mayo Clinic

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Oct 30, 2017

Athena Diagnostics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Charcot-Marie-Tooth disease

Uncertain:1

Molecular Genetics Laboratory, London Health Sciences Centre

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular phenotype

Uncertain:1

Nov 26, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.A129V variant (also known as c.386C>T), located in coding exon 4 of the TTR gene, results from a C to T substitution at nucleotide position 386. The alanine at codon 129 is replaced by valine, an amino acid with similar properties. Of note, this alteration is also designated as p.A109T in the published literature. This variant has been detected in individuals presenting with euthyroid hyperthyroxinemia, rather than transthyretin amyloidosis (Saraiva MJ. Hum. Mutat., 2001 Jun;17:493-503). In an assay testing TTR function, this variant showed a functionally normal result (Grether NB et al. Ann Clin Transl Neurol. 2022 Aug;9(8):1252-1263). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Amyloidosis, hereditary systemic 1

Uncertain:1

Oct 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 129 of the TTR protein (p.Ala129Val). This variant is present in population databases (rs121918092, gnomAD 0.003%). This missense change has been observed in individual(s) with clinical features of TTR-related conditions including euthyroid hyperthyroxinemia (PMID: 8784093, 28798025, 30847666). ClinVar contains an entry for this variant (Variation ID: 13454). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt TTR protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change does not substantially affect TTR function (PMID: 8784093, 35903975). This variant disrupts the p.Ala129 amino acid residue in TTR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9268242; internal data). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Hyperthyroxinemia, dystransthyretinemic

Other:1

Sep 01, 1996

OMIM

Significance:Affects

Review Status:no assertion criteria provided

Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Pathogenic

0.32

BayesDel_noAF

Pathogenic

0.30

CADD

Benign

(source)

DANN

Benign

0.92

DEOGEN2

Uncertain

0.60

D;D;.

Eigen

Benign

-0.34

Eigen_PC

Benign

-0.27

FATHMM_MKL

Benign

0.22

LIST_S2

Uncertain

0.89

.;D;T

M_CAP

Pathogenic

0.60

MetaRNN

Uncertain

0.61

D;D;D

MetaSVM

Uncertain

0.39

MutationAssessor

Benign

0.49

N;N;.

PhyloP100

2.4

PrimateAI

Benign

0.48

PROVEAN

Benign

0.57

.;N;.

REVEL

Uncertain

0.50

Sift

Benign

0.53

.;T;.

Sift4G

Benign

0.98

.;T;T

Polyphen

0.41

B;B;.

Vest4

0.48, 0.74

MutPred

0.66

Loss of glycosylation at T126 (P = 0.2601);Loss of glycosylation at T126 (P = 0.2601);.;

MVP

0.98

MPC

0.53

ClinPred

0.10

GERP RS

6.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.57

gMVP

0.90

Mutation Taster

=19/81

disease causing

(source)

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over