Genetic Variant TCN1:p.Leu411Pro (chr11-59853211-A-G) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_001062.4(TCN1):c.1232T>C(p.Leu411Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000547 in 1,461,860 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 (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

TCN1
NM_001062.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.48

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:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM1

In a binding_site (size 0) in uniprot entity TCO1_HUMAN

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.863

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TCN1	NM_001062.4 link	c.1232T>C	p.Leu411Pro	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.1232T>C	p.Leu411Pro	missense_variant	Exon 8 of 9	1	NM_001062.4	ENSP00000257264.3		P20061
TCN1	ENST00000529251.1 link	n.231T>C		non_coding_transcript_exon_variant	Exon 2 of 3	3

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

251374

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135854

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:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.00000547

AC:

AN:

1461860

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727240

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

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:

0.00

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

Cov.:

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Transcobalamin I deficiency

Uncertain:1

Apr 12, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 411 of the TCN1 protein (p.Leu411Pro). This variant is present in population databases (rs755268122, gnomAD 0.004%). 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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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

Pathogenic

0.70

BayesDel_addAF

Uncertain

0.16

BayesDel_noAF

Uncertain

0.090

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.25

Eigen

Uncertain

0.67

Eigen_PC

Uncertain

0.60

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Benign

0.62

M_CAP

Benign

0.016

MetaRNN

Pathogenic

0.86

MetaSVM

Benign

-0.80

MutationAssessor

Pathogenic

3.0

PrimateAI

Benign

0.41

PROVEAN

Pathogenic

-5.8

REVEL

Uncertain

0.38

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.77

MutPred

0.66

Gain of glycosylation at L411 (P = 0.0098);

MVP

0.59

MPC

0.13

ClinPred

0.91

GERP RS

5.2

Varity_R

0.90

gMVP

0.65

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.

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