Genetic Variant CD320:p.Arg258Ser (chr19-8302540-G-T) – ACMG Classification: Uncertain_significance (0 pts)

Variant summary

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

The NM_016579.4(CD320):c.772C>A(p.Arg258Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,508 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R258H) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

CD320
NM_016579.4 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: -0.290

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: AR, Unknown Classification: DEFINITIVE, SUPPORTIVE, LIMITED Submitted by: ClinGen, Orphanet, Ambry Genetics, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae)

CD320 links:

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=0.19587195).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_016579.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CD320	NM_016579.4	MANE Select	c.772C>A	p.Arg258Ser	missense	Exon 5 of 5	NP_057663.1	Q9NPF0-1
	CD320	NM_001165895.2		c.646C>A	p.Arg216Ser	missense	Exon 4 of 4	NP_001159367.1	Q9NPF0-2

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CD320	ENST00000301458.10	TSL:1 MANE Select	c.772C>A	p.Arg258Ser	missense	Exon 5 of 5	ENSP00000301458.4	Q9NPF0-1
CD320	ENST00000596002.5	TSL:1	n.*1060C>A		non_coding_transcript_exon	Exon 5 of 5	ENSP00000471773.1	M0R1C4
CD320	ENST00000596002.5	TSL:1	n.*1060C>A		3_prime_UTR	Exon 5 of 5	ENSP00000471773.1	M0R1C4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461508

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727032

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44708

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39682

South Asian (SAS)

AF:

0.00

AC:

AN:

86228

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53320

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111804

Other (OTH)

AF:

0.00

AC:

AN:

60388

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.225

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.27

BayesDel_addAF

Uncertain

0.017

BayesDel_noAF

Benign

-0.21

CADD

Benign

4.5

(source)

DANN

Benign

0.90

DEOGEN2

Benign

0.075

Eigen

Benign

-0.91

Eigen_PC

Benign

-1.0

FATHMM_MKL

Benign

0.056

LIST_S2

Benign

0.57

M_CAP

Benign

0.079

MetaRNN

Benign

0.20

MetaSVM

Uncertain

-0.033

MutationAssessor

Benign

1.1

PhyloP100

-0.29

PrimateAI

Benign

0.28

PROVEAN

Benign

-1.5

REVEL

Benign

0.16

Sift

Benign

0.30

Sift4G

Benign

0.40

Polyphen

0.32

Vest4

0.13

MutPred

0.34

Gain of loop (P = 0.0045)

MVP

0.87

MPC

0.15

ClinPred

0.088

GERP RS

-1.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.055

gMVP

0.32

Mutation Taster

=100/0

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over