chr18-31590520-G-T

Variant names:

• chr18-31590520-G-T
• rs3764478
• ENST00000649620.1:c.-1-1382G>T

Variant summary

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

The ENST00000649620.1(TTR):​c.-1-1382G>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0998 in 152,260 control chromosomes in the GnomAD database, including 907 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 0.10 (907 hom., cov: 33)
• Consequence: TTR ENST00000649620.1 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.360
• Publications: 12 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 (EAS) allele frequency at 95% confidence interval = 0.279 is higher than 0.05.

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000649620.1. 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

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTR	ENST00000649620.1		c.-1-1382G>T		intron	N/A	ENSP00000497927.1
	TTR	ENST00000610404.5	TSL:5	c.-27-2376G>T		intron	N/A	ENSP00000477599.2
	TTR	ENST00000613781.2	TSL:5	c.-1-1382G>T		intron	N/A	ENSP00000479174.2

Frequencies

GnomAD3 genomes AF: 0.0998 AC: 15181 AN: 152142 Hom.: 905 Cov.: 33

Gnomad AFR AF: 0.0664

Gnomad AMI AF: 0.114

Gnomad AMR AF: 0.0953

Gnomad ASJ AF: 0.107

Gnomad EAS AF: 0.292

Gnomad SAS AF: 0.111

Gnomad FIN AF: 0.0869

Gnomad MID AF: 0.146

Gnomad NFE AF: 0.106

Gnomad OTH AF: 0.118

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

GnomAD4 genome AF: 0.0998 AC: 15189 AN: 152260 Hom.: 907 Cov.: 33 AF XY: 0.101 AC XY: 7493 AN XY: 74438

African (AFR) AF: 0.0664 AC: 2757 AN: 41552

American (AMR) AF: 0.0951 AC: 1456 AN: 15306

Ashkenazi Jewish (ASJ) AF: 0.107 AC: 370 AN: 3472

East Asian (EAS) AF: 0.291 AC: 1507 AN: 5176

South Asian (SAS) AF: 0.112 AC: 540 AN: 4826

European-Finnish (FIN) AF: 0.0869 AC: 921 AN: 10602

Middle Eastern (MID) AF: 0.147 AC: 43 AN: 292

European-Non Finnish (NFE) AF: 0.106 AC: 7233 AN: 68012

Other (OTH) AF: 0.122 AC: 258 AN: 2110

Alfa AF: 0.0999 Hom.: 1567

Bravo AF: 0.0979

Asia WGS AF: 0.171 AC: 595 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	1.6
DANN	Benign	0.75
PhyloP100		0.36

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs3764478; hg19: chr18-29170483;