chr18-31598586-G-A

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 3P and 2B. PM1PP2BP6BS2_Supporting

The NM_000371.4(TTR):c.355G>A(p.Asp119Asn) variant causes a missense change. The variant allele was found at a frequency of 0.0000781 in 1,613,920 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D119V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000079 ( 0 hom. )

Consequence

TTR
NM_000371.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:5

Conservation

PhyloP100: 4.70

Publications

6 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 1 ACMG points.

PM1

In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 15 uncertain in NM_000371.4

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.

BP6

Variant 18-31598586-G-A is Benign according to our data. Variant chr18-31598586-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 181690.

BS2

High AC in GnomAd4 at 10 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTR	NM_000371.4	MANE Select	c.355G>A	p.Asp119Asn	missense	Exon 4 of 4	NP_000362.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TTR	ENST00000237014.8	TSL:1 MANE Select	c.355G>A	p.Asp119Asn	missense	Exon 4 of 4	ENSP00000237014.4
TTR	ENST00000649620.1		c.355G>A	p.Asp119Asn	missense	Exon 6 of 6	ENSP00000497927.1
TTR	ENST00000610404.5	TSL:5	c.259G>A	p.Asp87Asn	missense	Exon 4 of 4	ENSP00000477599.2

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152138

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000385

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000103

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000279

AC:

AN:

250980

AF XY:

0.0000147

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000163

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000794

AC:

116

AN:

1461782

Hom.:

Cov.:

AF XY:

0.0000963

AC XY:

AN XY:

727204

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:

0.00159

AC:

AN:

39698

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53312

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

1112012

Other (OTH)

AF:

0.0000331

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.489

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:

0.0000657

AC:

AN:

152138

Hom.:

Cov.:

AF XY:

0.0000673

AC XY:

AN XY:

74304

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41432

American (AMR)

AF:

0.0000655

AC:

AN:

15274

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.000385

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10596

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000103

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.495

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:

0.0000569

Hom.:

Bravo

AF:

0.0000453

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:5

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Amyloidosis, hereditary systemic 1

Uncertain:1Benign:1

Dec 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 119 of the TTR protein (p.Asp119Asn). This variant is present in population databases (rs76410435, gnomAD 0.02%). This missense change has been observed in individual(s) with clinical features of TTR-related conditions (PMID: 32376792, 34658264; internal data). This variant is also known as D99N. ClinVar contains an entry for this variant (Variation ID: 181690). 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: 21406045). 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.

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. The evidence from the literature, in combination with allele frequency data from public databases where available, was sufficient to determine this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign.

not provided

Benign:2

Dec 08, 2020

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 21406045, 30683924, 32376792)

Dec 20, 2017

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Likely benign

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

not specified

Benign:1

Jun 23, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: TTR c.355G>A (p.Asp119Asn) results in a conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 7.8e-05 in 1613920 control chromosomes. The observed variant frequency is approximately 2.5 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTR causing Transthyretin Amyloidosis phenotype (3.1e-05). c.355G>A has been reported in the literature without strong evidence for causality (Volodarsky_2021, Shrahina_2021). These report(s) do not provide unequivocal conclusions about association of the variant with Transthyretin Amyloidosis. Experimental studies have shown that this missense change does not substantially affect TTR function (Groenning_2011). The following publications have been ascertained in the context of this evaluation (PMID: 32376792, 34658264, 21406045). ClinVar contains an entry for this variant (Variation ID: 181690). Based on the evidence outlined above, the variant was classified as likely benign.

Cardiovascular phenotype

Benign:1

Jan 23, 2020

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.13

BayesDel_addAF

Benign

-0.038

BayesDel_noAF

Uncertain

-0.030

CADD

Benign

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.84

Eigen

Uncertain

0.35

Eigen_PC

Uncertain

0.28

FATHMM_MKL

Uncertain

0.93

LIST_S2

Benign

0.85

M_CAP

Uncertain

0.25

MetaRNN

Uncertain

0.72

MetaSVM

Pathogenic

0.93

MutationAssessor

Uncertain

2.4

PhyloP100

4.7

PrimateAI

Uncertain

0.55

PROVEAN

Benign

-2.1

REVEL

Pathogenic

0.68

Sift

Benign

0.19

Sift4G

Uncertain

0.026

Polyphen

0.98

Vest4

0.27

MutPred

0.60

Gain of glycosylation at T116 (P = 0.0856)

MVP

0.99

MPC

0.49

ClinPred

0.42

GERP RS

5.1

Varity_R

0.59

gMVP

0.86

Mutation Taster

=75/25

polymorphism

(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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over