22-30611036-A-T

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_000355.4(TCN2):​c.230A>T​(p.Lys77Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00106 in 1,614,076 control chromosomes in the GnomAD database, including 44 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K77R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0015 ( 9 hom., cov: 33)
Exomes 𝑓: 0.0010 ( 35 hom. )

Consequence

TCN2
NM_000355.4 missense

Scores

6
11

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: 1.38

Publications

11 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: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics, ClinGen, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -20 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.0064339936).
BP6
Variant 22-30611036-A-T is Benign according to our data. Variant chr22-30611036-A-T is described in ClinVar as Benign. ClinVar VariationId is 341190.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.0015 (229/152250) while in subpopulation EAS AF = 0.0422 (218/5170). AF 95% confidence interval is 0.0376. There are 9 homozygotes in GnomAd4. There are 138 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 9 AR gene

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000355.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TCN2
NM_000355.4
MANE Select
c.230A>Tp.Lys77Met
missense
Exon 2 of 9NP_000346.2
TCN2
NM_001184726.2
c.230A>Tp.Lys77Met
missense
Exon 2 of 9NP_001171655.1P20062-2

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TCN2
ENST00000215838.8
TSL:1 MANE Select
c.230A>Tp.Lys77Met
missense
Exon 2 of 9ENSP00000215838.3P20062-1
TCN2
ENST00000407817.3
TSL:1
c.230A>Tp.Lys77Met
missense
Exon 2 of 9ENSP00000384914.3P20062-2
TCN2
ENST00000947107.1
c.230A>Tp.Lys77Met
missense
Exon 2 of 10ENSP00000617166.1

Frequencies

GnomAD3 genomes
AF:
0.00151
AC:
229
AN:
152132
Hom.:
9
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.0421
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000118
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.00274
AC:
690
AN:
251400
AF XY:
0.00256
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.0000867
Gnomad ASJ exome
AF:
0.0000994
Gnomad EAS exome
AF:
0.0364
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00130
GnomAD4 exome
AF:
0.00102
AC:
1485
AN:
1461826
Hom.:
35
Cov.:
32
AF XY:
0.000943
AC XY:
686
AN XY:
727218
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000894
AC:
4
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.000191
AC:
5
AN:
26120
East Asian (EAS)
AF:
0.0349
AC:
1386
AN:
39700
South Asian (SAS)
AF:
0.0000812
AC:
7
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000369
AC:
41
AN:
1111970
Other (OTH)
AF:
0.000679
AC:
41
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.490
Heterozygous variant carriers
0
91
182
272
363
454
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
24
48
72
96
120
<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:
0.00150
AC:
229
AN:
152250
Hom.:
9
Cov.:
33
AF XY:
0.00185
AC XY:
138
AN XY:
74456
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41552
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.0422
AC:
218
AN:
5170
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000118
AC:
8
AN:
68014
Other (OTH)
AF:
0.000473
AC:
1
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.497
Heterozygous variant carriers
0
10
20
29
39
49
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
10
20
30
40
50
<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:
0.00126
Hom.:
4
Bravo
AF:
0.00426
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.00268
AC:
326
Asia WGS
AF:
0.00895
AC:
31
AN:
3478
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

ClinVar submissions as Germline
Significance:Benign
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
-
2
Transcobalamin II deficiency (2)
-
-
1
not provided (1)
-
-
1
TCN2-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.34
BayesDel_addAF
Benign
-0.42
T
BayesDel_noAF
Benign
-0.34
CADD
Uncertain
23
DANN
Uncertain
0.99
DEOGEN2
Benign
0.090
T
Eigen
Uncertain
0.24
Eigen_PC
Uncertain
0.29
FATHMM_MKL
Uncertain
0.82
D
LIST_S2
Benign
0.69
T
MetaRNN
Benign
0.0064
T
MetaSVM
Benign
-1.1
T
MutationAssessor
Uncertain
2.7
M
PhyloP100
1.4
PrimateAI
Benign
0.48
T
PROVEAN
Uncertain
-2.8
D
REVEL
Benign
0.20
Sift
Benign
0.052
T
Sift4G
Benign
0.18
T
Polyphen
0.73
P
Vest4
0.37
MVP
0.67
MPC
0.025
ClinPred
0.085
T
GERP RS
5.1
Varity_R
0.38
gMVP
0.54
Mutation Taster
=85/15
polymorphism

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

Other links and lift over

dbSNP: rs75680863; hg19: chr22-31007023; COSMIC: COSV53190900; COSMIC: COSV53190900; API