rs775586639

Positions:

chr22-30613024-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_000355.4(TCN2):c.409G>A(p.Asp137Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,613,934 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

TCN2
NM_000355.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.792

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 links:

TCN2 (HGNC:):

TCN2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.19529384).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TCN2	NM_000355.4 linkuse as main transcript	c.409G>A	p.Asp137Asn	missense_variant	3/9	ENST00000215838.8	NP_000346.2	P20062-1
TCN2	NM_001184726.2 linkuse as main transcript	c.346+63G>A		intron_variant			NP_001171655.1	P20062-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TCN2	ENST00000215838.8 linkuse as main transcript	c.409G>A	p.Asp137Asn	missense_variant	3/9	1	NM_000355.4	ENSP00000215838.3		P20062-1

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152174

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000145

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000797

AC:

AN:

250950

Hom.:

AF XY:

0.00000737

AC XY:

AN XY:

135674

show subpopulations

Gnomad AFR exome

AF:

0.000123

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000958

AC:

AN:

1461760

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727166

show subpopulations

Gnomad4 AFR exome

AF:

0.000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000180

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152174

Hom.:

Cov.:

AF XY:

0.0000673

AC XY:

AN XY:

74338

show subpopulations

Gnomad4 AFR

AF:

0.000145

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000659

Hom.:

Bravo

AF:

0.0000567

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Transcobalamin II deficiency

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 28, 2022

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 137 of the TCN2 protein (p.Asp137Asn). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 529777). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt TCN2 protein function. 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

Benign

0.079

BayesDel_addAF

Benign

-0.42

BayesDel_noAF

Benign

-0.61

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Benign

0.054

T;T;T

Eigen

Benign

0.097

Eigen_PC

Benign

0.14

FATHMM_MKL

Benign

0.50

LIST_S2

Benign

0.71

T;T;T

M_CAP

Benign

0.0093

MetaRNN

Benign

0.20

T;T;T

MetaSVM

Benign

-1.1

MutationAssessor

Uncertain

2.8

M;.;.

PrimateAI

Benign

0.38

PROVEAN

Benign

-0.56

N;.;N

REVEL

Benign

0.069

Sift

Benign

0.10

T;.;T

Sift4G

Benign

0.093

T;T;T

Polyphen

0.70

P;.;P

Vest4

0.24

MVP

0.61

MPC

0.0095

ClinPred

0.21

GERP RS

4.4

Varity_R

0.058

gMVP

0.19

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over