Genetic Variant TCN1:p.Pro384Leu (chr11-59853292-G-A) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001062.4(TCN1):c.1151C>T(p.Pro384Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000483 in 1,613,928 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000052 ( 0 hom. )

Consequence

TCN1
NM_001062.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.60

Variant links:

Genes affected

TCN1 (HGNC:11652): (transcobalamin 1) 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 protein is a major constituent of secondary granules in neutrophils and facilitates the transport of cobalamin into cells. [provided by RefSeq, Jul 2008]

TCN1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TCN1	NM_001062.4 link	c.1151C>T	p.Pro384Leu	missense_variant	Exon 8 of 9	ENST00000257264.4	NP_001053.2	P20061

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TCN1	ENST00000257264.4 link	c.1151C>T	p.Pro384Leu	missense_variant	Exon 8 of 9	1	NM_001062.4	ENSP00000257264.3		P20061
TCN1	ENST00000529251.1 link	n.150C>T		non_coding_transcript_exon_variant	Exon 2 of 3	3

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152066

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000415

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000916

AC:

AN:

251096

Hom.:

AF XY:

0.000125

AC XY:

AN XY:

135686

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 SAS exome

AF:

0.000719

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000520

AC:

AN:

1461862

Hom.:

Cov.:

AF XY:

0.0000798

AC XY:

AN XY:

727236

show subpopulations

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:

0.000812

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

8.99e-7

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000132

AC:

AN:

152066

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74262

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000415

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ExAC

AF:

0.0000988

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Transcobalamin I deficiency

Uncertain:1

Aug 28, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline with leucine at codon 384 of the TCN1 protein (p.Pro384Leu). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and leucine. This variant is present in population databases (rs745735811, ExAC 0.07%). This variant has not been reported in the literature in individuals affected with TCN1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0". The leucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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

0.16

BayesDel_addAF

Benign

-0.37

BayesDel_noAF

Benign

-0.39

CADD

Uncertain

DANN

Uncertain

0.98

DEOGEN2

Benign

0.17

Eigen

Benign

0.12

Eigen_PC

Benign

0.069

FATHMM_MKL

Benign

0.69

LIST_S2

Benign

0.72

M_CAP

Benign

0.011

MetaRNN

Uncertain

0.66

MetaSVM

Benign

-0.83

MutationAssessor

Benign

1.6

PrimateAI

Benign

0.39

PROVEAN

Pathogenic

-5.7

REVEL

Uncertain

0.29

Sift

Benign

0.15

Sift4G

Uncertain

0.059

Polyphen

1.0

Vest4

0.51

MutPred

0.83

Loss of loop (P = 0.0986);

MVP

0.51

MPC

0.12

ClinPred

0.59

GERP RS

2.1

Varity_R

0.16

gMVP

0.58

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.060

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