rs766909913

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 8P and 4B. PM1PM5PP3_StrongBS2

The NM_000371.4(TTR):c.406T>C(p.Tyr136His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,614,064 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y136S) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

TTR
NM_000371.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 3.40

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 Uncertain_significance. Variant got 4 ACMG points.

PM1

In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_000371.4

PM5

Other missense variant is known to change same aminoacid residue: Variant chr18-31598638-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 181700.Status of the report is criteria_provided_single_submitter, 1 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.96

BS2

High AC in GnomAdExome at 7 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTR	NM_000371.4 linkuse as main transcript	c.406T>C	p.Tyr136His	missense_variant	4/4	ENST00000237014.8
LOC124904277	XR_007066326.1 linkuse as main transcript	n.129-2942A>G		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris
TTR	ENST00000237014.8 linkuse as main transcript	c.406T>C	p.Tyr136His	missense_variant	4/4	1	NM_000371.4	P1
TTR	ENST00000649620.1 linkuse as main transcript	c.406T>C	p.Tyr136His	missense_variant	6/6			P1
TTR	ENST00000610404.5 linkuse as main transcript	c.310T>C	p.Tyr104His	missense_variant	4/4	5

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152184

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000278

AC:

AN:

251460

Hom.:

AF XY:

0.0000294

AC XY:

AN XY:

135910

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000202

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:

0.00

GnomAD4 exome

AF:

0.00000547

AC:

AN:

1461880

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727240

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000179

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:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152184

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74354

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hyperthyroxinemia, dystransthyretinemic;C2751492:Familial amyloid neuropathy;C5779776:Carpal tunnel syndrome 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Mar 15, 2022

- -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 21, 2016

The p.Y136H variant (also known as c.406T>C), located in coding exon 4 of the TTR gene, results from a T to C substitution at nucleotide position 406. The tyrosine at codon 136 is replaced by histidine, an amino acid with similar properties. Based on data from ExAC, the C allele has an overall frequency of approximately 0.008% (1/11214) total alleles studied. The highest observed frequency was <0.01% (1/106194) of Latino alleles. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Familial amyloid neuropathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 28, 2023

This sequence change replaces tyrosine, which is neutral and polar, with histidine, which is basic and polar, at codon 136 of the TTR protein (p.Tyr136His). This variant is present in population databases (rs766909913, gnomAD 0.02%). This missense change has been observed in individual(s) with amyloidosis (PMID: 29970125). This variant is also known as Y116H. ClinVar contains an entry for this variant (Variation ID: 582458). 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 with a positive predictive value of 95%. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.82

BayesDel_addAF

Pathogenic

0.19

BayesDel_noAF

Pathogenic

0.32

Cadd

Uncertain

Dann

Uncertain

1.0

DEOGEN2

Pathogenic

0.98

D;D;T;.

Eigen

Pathogenic

0.82

Eigen_PC

Pathogenic

0.71

FATHMM_MKL

Uncertain

0.90

M_CAP

Uncertain

0.13

MetaRNN

Pathogenic

0.96

D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.2

H;H;.;.

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.60

Polyphen

1.0

D;D;.;.

Vest4

0.53, 0.60, 0.52

MutPred

0.88

Gain of disorder (P = 0.0375);Gain of disorder (P = 0.0375);.;.;

MVP

0.99

MPC

1.6

ClinPred

0.99

GERP RS

6.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.90

gMVP

0.98

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