NM_000355.4:c.265T>C

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.265T>C​(p.Phe89Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0164 in 1,613,682 control chromosomes in the GnomAD database, including 278 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★). Synonymous variant affecting the same amino acid position (i.e. F89F) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.013 ( 24 hom., cov: 32)
Exomes 𝑓: 0.017 ( 254 hom. )

Consequence

TCN2
NM_000355.4 missense

Scores

17

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:4O:1

Conservation

PhyloP100: -2.59

Publications

7 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=0.0035916865).
BP6
Variant 22-30612880-T-C is Benign according to our data. Variant chr22-30612880-T-C is described in ClinVar as Benign. ClinVar VariationId is 341191.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.013 (1984/152324) while in subpopulation NFE AF = 0.0197 (1343/68034). AF 95% confidence interval is 0.0189. There are 24 homozygotes in GnomAd4. There are 955 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 24 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.265T>Cp.Phe89Leu
missense
Exon 3 of 9NP_000346.2
TCN2
NM_001184726.2
c.265T>Cp.Phe89Leu
missense
Exon 3 of 9NP_001171655.1P20062-2

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TCN2
ENST00000215838.8
TSL:1 MANE Select
c.265T>Cp.Phe89Leu
missense
Exon 3 of 9ENSP00000215838.3P20062-1
TCN2
ENST00000407817.3
TSL:1
c.265T>Cp.Phe89Leu
missense
Exon 3 of 9ENSP00000384914.3P20062-2
TCN2
ENST00000947107.1
c.265T>Cp.Phe89Leu
missense
Exon 3 of 10ENSP00000617166.1

Frequencies

GnomAD3 genomes
AF:
0.0130
AC:
1985
AN:
152206
Hom.:
24
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00367
Gnomad AMI
AF:
0.0439
Gnomad AMR
AF:
0.0139
Gnomad ASJ
AF:
0.0118
Gnomad EAS
AF:
0.00231
Gnomad SAS
AF:
0.0155
Gnomad FIN
AF:
0.00715
Gnomad MID
AF:
0.00316
Gnomad NFE
AF:
0.0197
Gnomad OTH
AF:
0.0158
GnomAD2 exomes
AF:
0.0133
AC:
3340
AN:
251270
AF XY:
0.0133
show subpopulations
Gnomad AFR exome
AF:
0.00345
Gnomad AMR exome
AF:
0.00755
Gnomad ASJ exome
AF:
0.00903
Gnomad EAS exome
AF:
0.00218
Gnomad FIN exome
AF:
0.00871
Gnomad NFE exome
AF:
0.0196
Gnomad OTH exome
AF:
0.0129
GnomAD4 exome
AF:
0.0168
AC:
24484
AN:
1461358
Hom.:
254
Cov.:
32
AF XY:
0.0168
AC XY:
12198
AN XY:
726996
show subpopulations
African (AFR)
AF:
0.00278
AC:
93
AN:
33458
American (AMR)
AF:
0.00736
AC:
329
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00957
AC:
250
AN:
26136
East Asian (EAS)
AF:
0.00151
AC:
60
AN:
39700
South Asian (SAS)
AF:
0.0139
AC:
1196
AN:
86240
European-Finnish (FIN)
AF:
0.00864
AC:
461
AN:
53380
Middle Eastern (MID)
AF:
0.00722
AC:
39
AN:
5400
European-Non Finnish (NFE)
AF:
0.0191
AC:
21187
AN:
1111974
Other (OTH)
AF:
0.0144
AC:
869
AN:
60348
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
1435
2869
4304
5738
7173
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
752
1504
2256
3008
3760
<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:
0.0130
AC:
1984
AN:
152324
Hom.:
24
Cov.:
32
AF XY:
0.0128
AC XY:
955
AN XY:
74484
show subpopulations
African (AFR)
AF:
0.00366
AC:
152
AN:
41574
American (AMR)
AF:
0.0139
AC:
212
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.0118
AC:
41
AN:
3472
East Asian (EAS)
AF:
0.00232
AC:
12
AN:
5180
South Asian (SAS)
AF:
0.0153
AC:
74
AN:
4830
European-Finnish (FIN)
AF:
0.00715
AC:
76
AN:
10626
Middle Eastern (MID)
AF:
0.00340
AC:
1
AN:
294
European-Non Finnish (NFE)
AF:
0.0197
AC:
1343
AN:
68034
Other (OTH)
AF:
0.0156
AC:
33
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.502
Heterozygous variant carriers
0
104
208
313
417
521
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
26
52
78
104
130
<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:
0.0181
Hom.:
78
Bravo
AF:
0.0120
TwinsUK
AF:
0.0200
AC:
74
ALSPAC
AF:
0.0182
AC:
70
ESP6500AA
AF:
0.00431
AC:
19
ESP6500EA
AF:
0.0191
AC:
164
ExAC
AF:
0.0139
AC:
1691
Asia WGS
AF:
0.00635
AC:
22
AN:
3478
EpiCase
AF:
0.0161
EpiControl
AF:
0.0172

ClinVar

ClinVar submissions as Germline
Significance:Benign
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
-
3
Transcobalamin II deficiency (3)
-
-
1
not provided (2)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.24
BayesDel_addAF
Benign
-0.72
T
BayesDel_noAF
Benign
-0.79
CADD
Benign
0.025
DANN
Benign
0.55
DEOGEN2
Benign
0.025
T
Eigen
Benign
-1.9
Eigen_PC
Benign
-1.9
FATHMM_MKL
Benign
0.027
N
LIST_S2
Benign
0.21
T
MetaRNN
Benign
0.0036
T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
-0.34
N
PhyloP100
-2.6
PrimateAI
Benign
0.31
T
PROVEAN
Benign
0.64
N
REVEL
Benign
0.023
Sift
Benign
0.82
T
Sift4G
Benign
0.66
T
Polyphen
0.0
B
Vest4
0.091
MutPred
0.24
Loss of catalytic residue at F89 (P = 0.0087)
MPC
0.0090
ClinPred
0.00087
T
GERP RS
-8.7
Varity_R
0.043
gMVP
0.14
Mutation Taster
=99/1
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: rs35915865; hg19: chr22-31008867; API