22-30610970-A-G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP3

The NM_000355.4(TCN2):c.164A>G(p.Tyr55Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000589 in 1,614,040 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y55S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000099 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000055 ( 0 hom. )

Consequence

TCN2
NM_000355.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.84

Publications

1 publications found

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]

TCN2 Gene-Disease associations (from GenCC):

transcobalamin II deficiency
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae), Orphanet

TCN2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.782

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TCN2	NM_000355.4 link	c.164A>G	p.Tyr55Cys	missense_variant	Exon 2 of 9	ENST00000215838.8	NP_000346.2	P20062-1
TCN2	NM_001184726.2 link	c.164A>G	p.Tyr55Cys	missense_variant	Exon 2 of 9		NP_001171655.1	P20062-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TCN2	ENST00000215838.8 link	c.164A>G	p.Tyr55Cys	missense_variant	Exon 2 of 9	1	NM_000355.4	ENSP00000215838.3		P20062-1

Frequencies

GnomAD3 genomes

AF:

0.0000986

AC:

AN:

152150

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.000865

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000103

Gnomad OTH

AF:

0.000957

GnomAD2 exomes

AF:

0.0000875

AC:

AN:

251488

AF XY:

0.0000956

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000260

Gnomad ASJ exome

AF:

0.000397

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000462

Gnomad NFE exome

AF:

0.0000527

Gnomad OTH exome

AF:

0.000326

GnomAD4 exome

AF:

0.0000547

AC:

AN:

1461890

Hom.:

Cov.:

AF XY:

0.0000646

AC XY:

AN XY:

727244

show subpopulations

African (AFR)

AF:

0.0000597

AC:

AN:

33480

American (AMR)

AF:

0.000291

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.000383

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000504

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000348

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.0000374

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000378

AC:

AN:

1112008

Other (OTH)

AF:

0.0000993

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.503

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000986

AC:

AN:

152150

Hom.:

Cov.:

AF XY:

0.000121

AC XY:

AN XY:

74314

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41440

American (AMR)

AF:

0.000131

AC:

AN:

15266

Ashkenazi Jewish (ASJ)

AF:

0.000865

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000103

AC:

AN:

68028

Other (OTH)

AF:

0.000957

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.495

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000104

Hom.:

Bravo

AF:

0.0000945

ExAC

AF:

0.0000576

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Transcobalamin II deficiency

Uncertain:1

Aug 31, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 55 of the TCN2 protein (p.Tyr55Cys). This variant is present in population databases (rs201701227, gnomAD 0.04%). This variant has not been reported in the literature in individuals affected with TCN2-related conditions. ClinVar contains an entry for this variant (Variation ID: 573502). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. 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

AlphaMissense

Uncertain

0.47

BayesDel_addAF

Benign

-0.043

BayesDel_noAF

Uncertain

0.020

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.19

T;T;T;.

Eigen

Uncertain

0.57

Eigen_PC

Uncertain

0.54

FATHMM_MKL

Uncertain

0.90

LIST_S2

Benign

0.84

T;D;T;T

M_CAP

Benign

0.036

MetaRNN

Pathogenic

0.78

D;D;D;D

MetaSVM

Benign

-0.44

MutationAssessor

Pathogenic

3.0

M;.;.;M

PhyloP100

2.8

PrimateAI

Uncertain

0.55

PROVEAN

Uncertain

-3.9

D;.;D;D

REVEL

Uncertain

0.36

Sift

Uncertain

0.0030

D;.;D;D

Sift4G

Pathogenic

0.0010

D;D;D;D

Polyphen

1.0

D;.;D;.

Vest4

0.86

MVP

0.92

MPC

0.057

ClinPred

0.88

GERP RS

5.1

Varity_R

0.71

gMVP

0.54

Mutation Taster

=63/37

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over