7-100620920-C-T

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_003227.4(TFR2):c.2343G>A(p.Trp781Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000322 in 1,614,060 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 Likely pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000032 (0 hom.)
• Consequence: TFR2 NM_003227.4 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.38

Genes affected

TFR2 (HGNC:11762): (transferrin receptor 2) This gene encodes a single-pass type II membrane protein, which is a member of the transferrin receptor-like family. This protein mediates cellular uptake of transferrin-bound iron, and may be involved in iron metabolism, hepatocyte function and erythrocyte differentiation. Mutations in this gene have been associated with hereditary hemochromatosis type III. Alternatively spliced transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq, May 2011]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 5 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-100620920-C-T is Pathogenic according to our data. Variant chr7-100620920-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 859038.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-100620920-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TFR2	NM_003227.4	c.2343G>A	p.Trp781Ter	stop_gained	18/18	ENST00000223051.8
TFR2	NM_001206855.3	c.1830G>A	p.Trp610Ter	stop_gained	15/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TFR2	ENST00000223051.8	c.2343G>A	p.Trp781Ter	stop_gained	18/18	1	NM_003227.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000328 AC: 5 AN: 152252 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

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: 0.0000441

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000798 AC: 2 AN: 250628 Hom.: 0 AF XY: 0.00000738 AC XY: 1 AN XY: 135550

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.00000885

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000322 AC: 47 AN: 1461808 Hom.: 0 Cov.: 31 AF XY: 0.0000344 AC XY: 25 AN XY: 727176

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.0000414

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000328 AC: 5 AN: 152252 Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3 AN XY: 74376

Gnomad4 AFR AF: 0.0000241

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: 0.0000441

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000647 Hom.: 0

Bravo AF: 0.0000264

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.000109

EpiControl AF: 0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hemochromatosis type 3 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jun 06, 2023	- -
Likely pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Aug 03, 2020	- -

Hereditary hemochromatosis Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jul 17, 2023

This sequence change creates a premature translational stop signal (p.Trp781*) in the TFR2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 21 amino acid(s) of the TFR2 protein. This variant is present in population databases (rs768907730, gnomAD 0.002%). This premature translational stop signal has been observed in individual(s) with hemochromatosis (PMID: 23600741). ClinVar contains an entry for this variant (Variation ID: 859038). This variant disrupts a region of the TFR2 protein in which other variant(s) (p.Gly792Arg) have been determined to be pathogenic (PMID: 16424658, 26029709). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.59
Cadd	Pathogenic	44
Dann	Uncertain	0.99
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Uncertain	0.94	D
MutationTaster	Benign	1.0	D;D;D;D
Vest4		0.85
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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

Other links and lift over

dbSNP: rs768907730; hg19: chr7-100218543;