rs762243340

Variant names:

• chr18-31591927-C-T
• rs762243340
• NM_000371.4:c.25C>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 1P and 1B. PP2 BS2_Supporting

The NM_000371.4(TTR):​c.25C>T​(p.Leu9Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000015 in 1,461,880 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000015 (0 hom.)
• Consequence: TTR NM_000371.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 0.572
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• 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.
• BS2: High AC in GnomAdExome4 at 22 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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTR	NM_000371.4	MANE Select	c.25C>T	p.Leu9Phe	missense	Exon 1 of 4	NP_000362.1	P02766

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTR	ENST00000237014.8	TSL:1 MANE Select	c.25C>T	p.Leu9Phe	missense	Exon 1 of 4	ENSP00000237014.4	P02766
	TTR	ENST00000649620.1		c.25C>T	p.Leu9Phe	missense	Exon 3 of 6	ENSP00000497927.1	P02766
	TTR	ENST00000858988.1		c.25C>T	p.Leu9Phe	missense	Exon 3 of 6	ENSP00000529047.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251434 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000150 AC: 22 AN: 1461880 Hom.: 0 Cov.: 30 AF XY: 0.00000688 AC XY: 5 AN XY: 727240

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000447 AC: 2 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000171 AC: 19 AN: 1112006

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Amyloidosis, hereditary systemic 1 (1)
-	1	-	Cardiovascular phenotype (1)
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.075
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.010
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.44	T
Eigen	Uncertain	0.30
Eigen_PC	Benign	0.21
FATHMM_MKL	Benign	0.63	D
LIST_S2	Uncertain	0.89	D
M_CAP	Pathogenic	0.32	D
MetaRNN	Uncertain	0.56	D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Pathogenic	3.0	M
PhyloP100		0.57
PrimateAI	Benign	0.37	T
PROVEAN	Benign	-1.1	N
REVEL	Uncertain	0.51
Sift	Uncertain	0.0080	D
Sift4G	Uncertain	0.018	D
Polyphen		0.96	D
Vest4		0.23
MutPred		0.29		Loss of loop (P = 0.1242)
MVP		0.94
MPC		1.1
ClinPred		0.92	D
GERP RS		4.0
PromoterAI		0.044	Neutral
Varity_R		0.12
gMVP		0.92
Mutation Taster		=57/43	polymorphism

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

Other links and lift over

dbSNP: rs762243340; hg19: chr18-29171890;