rs80338890

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1PM2PP5

The NM_003227.4(TFR2):​c.2137-1G>A variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000992 in 1,512,708 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

TFR2
NM_003227.4 splice_acceptor, intron

Scores

4
2
1
Splicing: ADA: 1.000
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1O:1

Conservation

PhyloP100: 7.57

Publications

3 publications found
Variant links:
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]
TFR2 Gene-Disease associations (from GenCC):
  • hemochromatosis type 3
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp, G2P

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 11 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease,
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 7-100621127-C-T is Pathogenic according to our data. Variant chr7-100621127-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 21371.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TFR2NM_003227.4 linkc.2137-1G>A splice_acceptor_variant, intron_variant Intron 17 of 17 ENST00000223051.8 NP_003218.2 Q9UP52-1
TFR2NM_001206855.3 linkc.1624-1G>A splice_acceptor_variant, intron_variant Intron 14 of 14 NP_001193784.1 Q9UP52-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TFR2ENST00000223051.8 linkc.2137-1G>A splice_acceptor_variant, intron_variant Intron 17 of 17 1 NM_003227.4 ENSP00000223051.3 Q9UP52-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152258
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000771
AC:
1
AN:
129684
AF XY:
0.00
show subpopulations
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000216
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000103
AC:
14
AN:
1360450
Hom.:
0
Cov.:
31
AF XY:
0.0000105
AC XY:
7
AN XY:
664324
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31028
American (AMR)
AF:
0.00
AC:
0
AN:
33980
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
23116
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35158
South Asian (SAS)
AF:
0.00
AC:
0
AN:
74402
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
48000
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4190
European-Non Finnish (NFE)
AF:
0.0000133
AC:
14
AN:
1054308
Other (OTH)
AF:
0.00
AC:
0
AN:
56268
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.00000657
AC:
1
AN:
152258
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74382
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41472
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68050
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:1Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Hemochromatosis type 3 Pathogenic:1Other:1
-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

Dec 04, 2023
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hereditary hemochromatosis Uncertain:1
Aug 24, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change affects an acceptor splice site in intron 17 of the TFR2 gene. While this variant is not anticipated to result in nonsense mediated decay, it likely alters RNA splicing and results in a disrupted protein product. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the ExAC database. Disruption of this splice site has been observed in individual(s) with hereditary hemochromatosis (PMID: 18245657). This variant is also known as IVS17+5636G>A. ClinVar contains an entry for this variant (Variation ID: 21371). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.58
D
BayesDel_noAF
Pathogenic
0.32
CADD
Pathogenic
34
DANN
Uncertain
1.0
Eigen
Pathogenic
1.2
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Uncertain
0.97
D
PhyloP100
7.6
GERP RS
5.4
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.94
SpliceAI score (max)
1.0
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.81
Position offset: -25
DS_AL_spliceai
1.0
Position offset: -1

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

Publications

Other links and lift over

dbSNP: rs80338890; hg19: chr7-100218750; API