Genetic Variant NM_000371.4:c.148G>A (chr18-31592974-G-A) – ACMG Classification: Pathogenic (13 pts)

Variant summary

Our verdict is Pathogenic. The variant received 13 ACMG points: 14P and 1B. PM1PM5PP2PP3PP5_Very_StrongBS2_Supporting

The NM_000371.4(TTR):c.148G>A(p.Val50Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000057 in 1,614,098 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V50L) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000058 ( 0 hom. )

Consequence

TTR
NM_000371.4 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:39O:1

Conservation

PhyloP100: 2.83

Publications

910 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

TTR links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 13 ACMG points.

PM1

In a hotspot region, there are 21 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_000371.4

PM5

Other missense variant is known to change same aminoacid residue: Variant chr18-31592974-G-C is described in ClinVar as Pathogenic. ClinVar VariationId is 13440.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 108 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Gene score misZ: 1.0149 (below the threshold of 3.09). Trascript score misZ: 1.5458 (below the threshold of 3.09). GenCC associations: The gene is linked to familial amyloid neuropathy, amyloidosis, hereditary systemic 1, ATTRV122I amyloidosis, hereditary ATTR amyloidosis, heart conduction disease.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.817

PP5

Variant 18-31592974-G-A is Pathogenic according to our data. Variant chr18-31592974-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 13417.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS2

High AC in GnomAd4 at 7 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000371.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTR	NM_000371.4	MANE Select	c.148G>A	p.Val50Met	missense	Exon 2 of 4	NP_000362.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TTR	ENST00000237014.8	TSL:1 MANE Select	c.148G>A	p.Val50Met	missense	Exon 2 of 4	ENSP00000237014.4
TTR	ENST00000649620.1		c.148G>A	p.Val50Met	missense	Exon 4 of 6	ENSP00000497927.1
TTR	ENST00000858988.1		c.148G>A	p.Val50Met	missense	Exon 4 of 6	ENSP00000529047.1

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152174

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000103

AC:

AN:

251462

AF XY:

0.000110

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000924

Gnomad NFE exome

AF:

0.000167

Gnomad OTH exome

AF:

0.000489

GnomAD4 exome

AF:

0.0000581

AC:

AN:

1461806

Hom.:

Cov.:

AF XY:

0.0000536

AC XY:

AN XY:

727214

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33474

American (AMR)

AF:

0.0000447

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39696

South Asian (SAS)

AF:

0.0000348

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.0000749

AC:

AN:

53406

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000531

AC:

AN:

1111956

Other (OTH)

AF:

0.000232

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.459

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000460

AC:

AN:

152292

Hom.:

Cov.:

AF XY:

0.0000672

AC XY:

AN XY:

74458

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41560

American (AMR)

AF:

0.000196

AC:

AN:

15296

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.000193

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68032

Other (OTH)

AF:

0.00

AC:

AN:

2110

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.554

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.0000443

Hom.:

Bravo

AF:

0.0000302

ExAC

AF:

0.000148

AC:

ClinVar

ClinVar submissions as Germline

Significance:Pathogenic

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (17)

Amyloidosis, hereditary systemic 1 (16)

Cardiovascular phenotype (2)

Hyperthyroxinemia, dystransthyretinemic;C2751492:Amyloidosis, hereditary systemic 1;C5779776:Carpal tunnel syndrome 1 (2)

Cardiomyopathy (1)

Charcot-Marie-Tooth disease (1)

TTR-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.35

BayesDel_addAF

Pathogenic

0.33

BayesDel_noAF

Pathogenic

0.50

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.86

Eigen

Uncertain

0.65

Eigen_PC

Uncertain

0.52

FATHMM_MKL

Benign

0.74

LIST_S2

Uncertain

0.94

M_CAP

Pathogenic

0.37

MetaRNN

Pathogenic

0.82

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.8

PhyloP100

2.8

PrimateAI

Benign

0.45

PROVEAN

Benign

-1.6

REVEL

Pathogenic

0.71

Sift

Uncertain

0.025

Sift4G

Uncertain

0.0090

Polyphen

1.0

Vest4

0.70

MVP

0.99

MPC

1.3

ClinPred

0.60

GERP RS

5.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.67

gMVP

0.97

Mutation Taster

=11/89

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over