rs121918087

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1PM2PM5PP3_StrongPP5_Moderate

The NM_000371.4(TTR):​c.350C>A​(p.Ala117Asp) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,824 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A117G) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TTR
NM_000371.4 missense

Scores

12
5
2

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 6.09
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PM1
In a chain Transthyretin (size 126) in uniprot entity TTHY_HUMAN there are 141 pathogenic changes around while only 6 benign (96%) in NM_000371.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr18-31598581-C-G is described in Lovd as [Pathogenic].
PP3
MetaRNN computational evidence supports a deleterious effect, 0.985
PP5
Variant 18-31598581-C-A is Pathogenic according to our data. Variant chr18-31598581-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2057055.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTRNM_000371.4 linkc.350C>A p.Ala117Asp missense_variant Exon 4 of 4 ENST00000237014.8 NP_000362.1 P02766E9KL36
LOC124904277XR_007066326.1 linkn.129-2886G>T intron_variant Intron 1 of 1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTRENST00000237014.8 linkc.350C>A p.Ala117Asp missense_variant Exon 4 of 4 1 NM_000371.4 ENSP00000237014.4 P02766
TTRENST00000649620.1 linkc.350C>A p.Ala117Asp missense_variant Exon 6 of 6 ENSP00000497927.1 P02766
TTRENST00000610404.5 linkc.254C>A p.Ala85Asp missense_variant Exon 4 of 4 5 ENSP00000477599.2 A0A087WT59

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461824
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727220
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Amyloidosis, hereditary systemic 1 Pathogenic:1
Nov 01, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 117 of the TTR protein (p.Ala117Asp). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TTR-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TTR protein function. This variant disrupts the p.Ala117 amino acid residue in TTR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10611950, 18022643, 20697105, 22412233, 23713495). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.93
BayesDel_addAF
Pathogenic
0.50
D
BayesDel_noAF
Pathogenic
0.48
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.95
D;D;T;.
Eigen
Pathogenic
0.80
Eigen_PC
Pathogenic
0.72
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Benign
0.77
.;T;T;T
M_CAP
Pathogenic
0.54
D
MetaRNN
Pathogenic
0.98
D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.4
M;M;.;.
PrimateAI
Uncertain
0.73
T
PROVEAN
Uncertain
-3.6
.;D;.;.
REVEL
Pathogenic
0.87
Sift
Uncertain
0.0040
.;D;.;.
Sift4G
Uncertain
0.025
.;D;D;D
Polyphen
1.0
D;D;.;.
Vest4
0.95, 0.96, 0.80
MutPred
0.85
Gain of disorder (P = 0.0363);Gain of disorder (P = 0.0363);Gain of disorder (P = 0.0363);.;
MVP
1.0
MPC
1.7
ClinPred
0.99
D
GERP RS
6.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.96
gMVP
0.99

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr18-29178544; API