chr18-31598615-C-T

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_StrongBP6BP7BS2_Supporting

The NM_000371.4(TTR):​c.384C>T​(p.Ala128Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000134 in 1,614,108 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00014 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00013 ( 0 hom. )

Consequence

TTR
NM_000371.4 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:13

Conservation

PhyloP100: -5.54

Publications

1 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -7 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.69).
BP6
Variant 18-31598615-C-T is Benign according to our data. Variant chr18-31598615-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 197136.
BP7
Synonymous conserved (PhyloP=-5.54 with no splicing effect.
BS2
High AC in GnomAd4 at 21 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
TTRNM_000371.4 linkc.384C>T p.Ala128Ala synonymous_variant Exon 4 of 4 ENST00000237014.8 NP_000362.1
LOC124904277XR_007066326.1 linkn.129-2920G>A intron_variant Intron 1 of 1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTRENST00000237014.8 linkc.384C>T p.Ala128Ala synonymous_variant Exon 4 of 4 1 NM_000371.4 ENSP00000237014.4
TTRENST00000649620.1 linkc.384C>T p.Ala128Ala synonymous_variant Exon 6 of 6 ENSP00000497927.1
TTRENST00000610404.5 linkc.288C>T p.Ala96Ala synonymous_variant Exon 4 of 4 5 ENSP00000477599.2
ENSG00000294516ENST00000724044.1 linkn.286-2920G>A intron_variant Intron 2 of 2

Frequencies

GnomAD3 genomes
AF:
0.000138
AC:
21
AN:
152238
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000965
Gnomad AMI
AF:
0.00110
Gnomad AMR
AF:
0.00
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:
0.000235
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000915
AC:
23
AN:
251426
AF XY:
0.0000957
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:
0.000176
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000133
AC:
195
AN:
1461870
Hom.:
0
Cov.:
31
AF XY:
0.000131
AC XY:
95
AN XY:
727236
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000348
AC:
3
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53398
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000167
AC:
186
AN:
1112012
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.465
Heterozygous variant carriers
0
13
26
38
51
64
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.000138
AC:
21
AN:
152238
Hom.:
0
Cov.:
33
AF XY:
0.000121
AC XY:
9
AN XY:
74378
show subpopulations
African (AFR)
AF:
0.0000965
AC:
4
AN:
41468
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000235
AC:
16
AN:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.506
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000369
Hom.:
0
Bravo
AF:
0.000181
EpiCase
AF:
0.000218
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:13
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:3
-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

May 15, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jun 13, 2019
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Benign:4
Mar 03, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Clinical Genetics, Academic Medical Center
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Oct 10, 2018
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Ala128Ala variant in TTR is classified as likely benign because it does no t alter an amino acid residue, it is not located within the splice consensus seq uence, and splice prediction algorithms do not predict a newly created splice si te. It has also been identified in 0.01% (24/126672) of European chromosomes by gnomAD (http://gnomad.broadinstitute.org). ACMG/AMP Criteria applied: BP4, BP7, BS1_Supporting. -

Feb 18, 2016
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Amyloidosis, hereditary systemic 1 Benign:2
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Feb 03, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Charcot-Marie-Tooth disease Benign:1
-
Molecular Genetics Laboratory, London Health Sciences Centre
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiomyopathy Benign:1
Mar 20, 2020
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

TTR-related disorder Benign:1
May 10, 2024
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Cardiovascular phenotype Benign:1
Dec 08, 2014
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 v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.69
CADD
Benign
0.073
DANN
Benign
0.45
PhyloP100
-5.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=99/1
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

Publications

Other links and lift over

dbSNP: rs143906738; hg19: chr18-29178578; COSMIC: COSV99379623; COSMIC: COSV99379623; API