22-30610895-T-G

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_000355.4(TCN2):​c.89T>G​(p.Leu30Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000661 in 1,614,246 control chromosomes in the GnomAD database, including 12 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0036 ( 9 hom., cov: 33)
Exomes 𝑓: 0.00036 ( 3 hom. )

Consequence

TCN2
NM_000355.4 missense

Scores

1
5
12

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: 2.90
Variant links:
Genes affected
TCN2 (HGNC:11653): (transcobalamin 2) This gene encodes a member of the vitamin B12-binding protein family. This family of proteins, alternatively referred to as R binders, is expressed in various tissues and secretions. This plasma protein binds cobalamin and mediates the transport of cobalamin into cells. This protein and other mammalian cobalamin-binding proteins, such as transcobalamin I and gastric intrisic factor, may have evolved by duplication of a common ancestral gene. Alternative splicing results in multiple transcript variants.[provided by RefSeq, May 2010]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -20 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.0114066005).
BP6
Variant 22-30610895-T-G is Benign according to our data. Variant chr22-30610895-T-G is described in ClinVar as [Likely_benign]. Clinvar id is 529781.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00357 (544/152352) while in subpopulation AFR AF= 0.0124 (515/41588). AF 95% confidence interval is 0.0115. There are 9 homozygotes in gnomad4. There are 262 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.
BS2
High Homozygotes in GnomAd4 at 9 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TCN2NM_000355.4 linkc.89T>G p.Leu30Arg missense_variant Exon 2 of 9 ENST00000215838.8 NP_000346.2 P20062-1
TCN2NM_001184726.2 linkc.89T>G p.Leu30Arg missense_variant Exon 2 of 9 NP_001171655.1 P20062-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TCN2ENST00000215838.8 linkc.89T>G p.Leu30Arg missense_variant Exon 2 of 9 1 NM_000355.4 ENSP00000215838.3 P20062-1

Frequencies

GnomAD3 genomes
AF:
0.00357
AC:
543
AN:
152234
Hom.:
9
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0124
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00131
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:
0.0000294
Gnomad OTH
AF:
0.00335
GnomAD3 exomes
AF:
0.000922
AC:
232
AN:
251494
Hom.:
3
AF XY:
0.000618
AC XY:
84
AN XY:
135922
show subpopulations
Gnomad AFR exome
AF:
0.0130
Gnomad AMR exome
AF:
0.000463
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000653
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000358
AC:
523
AN:
1461894
Hom.:
3
Cov.:
32
AF XY:
0.000276
AC XY:
201
AN XY:
727248
show subpopulations
Gnomad4 AFR exome
AF:
0.0133
Gnomad4 AMR exome
AF:
0.000402
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000232
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000719
Gnomad4 OTH exome
AF:
0.000762
GnomAD4 genome
AF:
0.00357
AC:
544
AN:
152352
Hom.:
9
Cov.:
33
AF XY:
0.00352
AC XY:
262
AN XY:
74494
show subpopulations
Gnomad4 AFR
AF:
0.0124
Gnomad4 AMR
AF:
0.00131
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000294
Gnomad4 OTH
AF:
0.00331
Alfa
AF:
0.000181
Hom.:
0
Bravo
AF:
0.00416
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.0111
AC:
49
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.00112
AC:
136
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Transcobalamin II deficiency Benign:2
Sep 21, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Feb 01, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

TCN2-related disorder Benign:1
May 20, 2019
PreventionGenetics, part of Exact Sciences
Significance: Benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

not provided Benign:1
Oct 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

TCN2: BP4, BS1 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.098
BayesDel_addAF
Benign
-0.36
T
BayesDel_noAF
Benign
-0.28
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.14
T;T;T;.
Eigen
Uncertain
0.60
Eigen_PC
Uncertain
0.53
FATHMM_MKL
Uncertain
0.86
D
LIST_S2
Benign
0.75
T;T;T;T
MetaRNN
Benign
0.011
T;T;T;T
MetaSVM
Benign
-0.50
T
MutationAssessor
Pathogenic
3.1
M;.;.;M
PrimateAI
Benign
0.47
T
PROVEAN
Benign
-1.8
N;.;N;N
REVEL
Uncertain
0.45
Sift
Benign
0.081
T;.;T;T
Sift4G
Benign
0.11
T;T;T;T
Polyphen
1.0
D;.;D;.
Vest4
0.85
MVP
0.83
MPC
0.054
ClinPred
0.087
T
GERP RS
6.2
Varity_R
0.23
gMVP
0.80

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs116605132; hg19: chr22-31006882; API