rs1423660217

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_016579.4(CD320):​c.685T>C​(p.Tyr229His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,992 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

CD320
NM_016579.4 missense

Scores

1
4
14

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.452

Publications

0 publications found
Variant links:
Genes affected
CD320 (HGNC:16692): (CD320 molecule) This gene encodes the transcobalamin receptor that is expressed at the cell surface. It mediates the cellular uptake of transcobalamin bound cobalamin (vitamin B12), and is involved in B-cell proliferation and immunoglobulin secretion. Mutations in this gene are associated with methylmalonic aciduria. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Jan 2011]
CD320 Gene-Disease associations (from GenCC):
  • methylmalonic acidemia due to transcobalamin receptor defect
    Inheritance: Unknown, AR Classification: DEFINITIVE, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet, ClinGen, Laboratory for Molecular Medicine

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.11943442).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CD320NM_016579.4 linkc.685T>C p.Tyr229His missense_variant Exon 4 of 5 ENST00000301458.10 NP_057663.1 Q9NPF0-1
CD320NM_001165895.2 linkc.559T>C p.Tyr187His missense_variant Exon 3 of 4 NP_001159367.1 Q9NPF0-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CD320ENST00000301458.10 linkc.685T>C p.Tyr229His missense_variant Exon 4 of 5 1 NM_016579.4 ENSP00000301458.4 Q9NPF0-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152116
Hom.:
0
Cov.:
32
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:
0.00
Gnomad FIN
AF:
0.0000942
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461876
Hom.:
0
Cov.:
33
AF XY:
0.00000413
AC XY:
3
AN XY:
727238
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1111998
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.00000657
AC:
1
AN:
152116
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74302
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41426
American (AMR)
AF:
0.00
AC:
0
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.0000942
AC:
1
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68010
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000282
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Methylmalonic acidemia due to transcobalamin receptor defect Uncertain:1
Oct 14, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This variant has not been reported in the literature in individuals affected with CD320-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces tyrosine, which is neutral and polar, with histidine, which is basic and polar, at codon 229 of the CD320 protein (p.Tyr229His). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.28
BayesDel_addAF
Uncertain
0.032
T
BayesDel_noAF
Benign
-0.19
CADD
Benign
18
DANN
Uncertain
0.99
DEOGEN2
Benign
0.087
.;T
Eigen
Benign
-0.92
Eigen_PC
Benign
-0.98
FATHMM_MKL
Benign
0.045
N
LIST_S2
Benign
0.64
T;T
M_CAP
Benign
0.074
D
MetaRNN
Benign
0.12
T;T
MetaSVM
Uncertain
0.053
D
MutationAssessor
Benign
1.3
.;L
PhyloP100
0.45
PrimateAI
Benign
0.35
T
PROVEAN
Benign
-2.1
N;N
REVEL
Benign
0.15
Sift
Pathogenic
0.0
D;D
Sift4G
Uncertain
0.016
D;D
Polyphen
0.069
.;B
Vest4
0.17
MutPred
0.46
.;Gain of disorder (P = 0.0245);
MVP
0.74
MPC
0.17
ClinPred
0.15
T
GERP RS
-0.38
Varity_R
0.18
gMVP
0.63
Mutation Taster
=98/2
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: rs1423660217; hg19: chr19-8367682; API