18-31598668-A-G

Position:

chr18-31598668-A-G

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 2P and 13B. PM1BP4_StrongBP6_Very_StrongBS2_Supporting

The ENST00000237014.8(TTR):c.437A>G(p.Lys146Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000663 in 1,614,150 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. K146K) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000068 ( 0 hom. )

Consequence

TTR
ENST00000237014.8 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: 1.28

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 links:

LOC124904277 (HGNC:):

LOC124904277 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -11 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 4 uncertain in ENST00000237014.8

BP4

Computational evidence support a benign effect (MetaRNN=0.008453041).

BP6

Variant 18-31598668-A-G is Benign according to our data. Variant chr18-31598668-A-G is described in ClinVar as [Likely_benign]. Clinvar id is 181706.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS2

High AC in GnomAd4 at 8 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/exons	MANE	Protein	UniProt
TTR	NM_000371.4 linkuse as main transcript	c.437A>G	p.Lys146Arg	missense_variant	4/4	ENST00000237014.8	NP_000362.1
LOC124904277	XR_007066326.1 linkuse as main transcript	n.129-2973T>C		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris
TTR	ENST00000237014.8 linkuse as main transcript	c.437A>G	p.Lys146Arg	missense_variant	4/4	1	NM_000371.4	ENSP00000237014	P1
TTR	ENST00000649620.1 linkuse as main transcript	c.437A>G	p.Lys146Arg	missense_variant	6/6			ENSP00000497927	P1
TTR	ENST00000610404.5 linkuse as main transcript	c.341A>G	p.Lys114Arg	missense_variant	4/4	5		ENSP00000477599

Frequencies

GnomAD3 genomes

AF:

0.0000526

AC:

AN:

152168

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000458

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000350

AC:

AN:

251400

Hom.:

AF XY:

0.000213

AC XY:

AN XY:

135872

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00252

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000677

AC:

AN:

1461864

Hom.:

Cov.:

AF XY:

0.0000509

AC XY:

AN XY:

727236

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00219

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000525

AC:

AN:

152286

Hom.:

Cov.:

AF XY:

0.0000537

AC XY:

AN XY:

74460

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000457

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000680

Hom.:

Bravo

AF:

0.000170

ExAC

AF:

0.000395

AC:

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:2

Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	May 18, 2017	Variant summary: The TTR c.437A>G (p.Lys146Arg) variant involves the alteration of a non-conserved nucleotide. 5/5 in silico tools predict a benign outcome for this variant. This variant was found in 48/121306 control chromosomes, predominantly observed in the Latino subpopulation at a frequency of 0.004151 (48/11564). This frequency is about 133 times the estimated maximal expected allele frequency of a pathogenic TTR variant (0.0000313), suggesting this is likely a benign polymorphism found primarily in the populations of Latino origin. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as likely benign. Taken together, this variant is classified as benign. -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jul 30, 2020	- -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 27, 2019

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. -

Amyloidosis, hereditary systemic 1

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.075

BayesDel_addAF

Benign

-0.26

BayesDel_noAF

Benign

-0.16

CADD

Benign

1.0

DANN

Benign

0.75

DEOGEN2

Benign

0.21

T;T;T;.

Eigen

Benign

-1.1

Eigen_PC

Benign

-1.1

FATHMM_MKL

Benign

0.088

LIST_S2

Benign

0.51

.;T;T;T

M_CAP

Benign

0.053

MetaRNN

Benign

0.0085

T;T;T;T

MetaSVM

Uncertain

-0.28

MutationAssessor

Benign

1.2

L;L;.;.

MutationTaster

Benign

1.0

PrimateAI

Benign

0.23

PROVEAN

Benign

-0.36

.;N;.;.

REVEL

Uncertain

0.38

Sift

Benign

0.28

.;T;.;.

Sift4G

Benign

0.58

.;T;T;T

Polyphen

0.0

B;B;.;.

Vest4

0.081, 0.29, 0.17

MutPred

0.23

Loss of ubiquitination at K146 (P = 0.0051);Loss of ubiquitination at K146 (P = 0.0051);.;.;

MVP

0.87

MPC

0.38

ClinPred

0.033

GERP RS

0.67

Varity_R

0.12

gMVP

0.85

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over