rs13381331

Variant names:

• chr18-31594224-G-A
• rs13381331
• NM_000371.4:c.201-896G>A

Variant summary

Our verdict is Benign. The variant received -12 ACMG points: 0P and 12B. BP4_Strong BA1

The NM_000371.4(TTR):​c.201-896G>A variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0286 in 152,190 control chromosomes in the GnomAD database, including 210 homozygotes. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.029 (210 hom., cov: 32)
• Consequence: TTR NM_000371.4 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.202
• Publications: 2 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: Benign. The variant received -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.85).
• BA1: GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.0973 is higher than 0.05.

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.201-896G>A		intron	N/A	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.201-896G>A		intron	N/A	ENSP00000237014.4	P02766
	TTR	ENST00000649620.1		c.201-896G>A		intron	N/A	ENSP00000497927.1	P02766
	TTR	ENST00000858988.1		c.201-896G>A		intron	N/A	ENSP00000529047.1

Frequencies

GnomAD3 genomes AF: 0.0286 AC: 4349 AN: 152078 Hom.: 211 Cov.: 32

Gnomad AFR AF: 0.100

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00877

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.000622

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00316

Gnomad NFE AF: 0.000323

Gnomad OTH AF: 0.0202

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.0286 AC: 4348 AN: 152190 Hom.: 210 Cov.: 32 AF XY: 0.0274 AC XY: 2041 AN XY: 74414

African (AFR) AF: 0.0999 AC: 4145 AN: 41510

American (AMR) AF: 0.00876 AC: 134 AN: 15296

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5184

South Asian (SAS) AF: 0.000622 AC: 3 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10582

Middle Eastern (MID) AF: 0.00340 AC: 1 AN: 294

European-Non Finnish (NFE) AF: 0.000323 AC: 22 AN: 68016

Other (OTH) AF: 0.0199 AC: 42 AN: 2106

Alfa AF: 0.0156 Hom.: 35

Bravo AF: 0.0329

Asia WGS AF: 0.00462 AC: 17 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.85
CADD	Benign	1.9
DANN	Benign	0.38
PhyloP100		-0.20
Mutation Taster		=100/0	polymorphism (auto)

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: rs13381331; hg19: chr18-29174187;