chr18-31591902-G-C

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_StrongBS2_Supporting

The NM_000371.4(TTR):c.-1G>C variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000353 in 1,614,024 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000037 ( 0 hom. )

Consequence

TTR
NM_000371.4 5_prime_UTR

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: -0.0370

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.67).

BS2

High AC in GnomAdExome4 at 54 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.-1G>C		5_prime_UTR_variant	Exon 1 of 4	ENST00000237014.8	NP_000362.1	P02766E9KL36

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTR	ENST00000237014 link	c.-1G>C		5_prime_UTR_variant	Exon 1 of 4	1	NM_000371.4	ENSP00000237014.4		P02766

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152158

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251382

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135860

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

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:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000369

AC:

AN:

1461866

Hom.:

Cov.:

AF XY:

0.0000289

AC XY:

AN XY:

727238

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

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:

0.0000477

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152158

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74326

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000959

Hom.:

Bravo

AF:

0.0000264

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Jul 05, 2017

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: This variant involves the alteration of a non-conserved nucleotide located in the 5 UTR region. One in silico tools predict damaging outcome. 3/5 splice prediction tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. This variant was found in 1/121378 control chromosomes at a frequency of 0.0000082, which does not exceed the estimated maximal expected allele frequency of a pathogenic TTR variant (0.0000313). The variant of interest has not, to our knowledge, been reported in affected individuals via publications and/or reputable databases/clinical diagnostic laboratories; nor evaluated for functional impact by in vivo/vitro studies. Taken together, due to lack of clinical and functional evidence, this variant is classified as VUS. -

Cardiovascular phenotype

Uncertain:1

Feb 10, 2020

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.-1G>C variant is located in the 5' untranslated region (5’ UTR) of the TTR gene. This variant results from a G to C substitution 1 base upstream from the first translated codon. This nucleotide position is not well conserved in available vertebrate species. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.67

CADD

Benign

DANN

Benign

0.82

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

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