22-30615363-C-A

Variant names:

• chr22-30615363-C-A
• rs35838082
• NM_000355.4:c.643C>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_000355.4(TCN2):​c.643C>A​(p.Arg215Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 152,076 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: TCN2 NM_000355.4 synonymous
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.61
• Publications: 16 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

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.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TCN2	NM_000355.4	MANE Select	c.643C>A	p.Arg215Arg	synonymous	Exon 5 of 9	NP_000346.2
	TCN2	NM_001184726.2		c.562C>A	p.Arg188Arg	synonymous	Exon 5 of 9	NP_001171655.1	P20062-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TCN2	ENST00000215838.8	TSL:1 MANE Select	c.643C>A	p.Arg215Arg	synonymous	Exon 5 of 9	ENSP00000215838.3	P20062-1
	TCN2	ENST00000407817.3	TSL:1	c.562C>A	p.Arg188Arg	synonymous	Exon 5 of 9	ENSP00000384914.3	P20062-2
	TCN2	ENST00000947107.1		c.643C>A	p.Arg215Arg	synonymous	Exon 5 of 10	ENSP00000617166.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152076 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000242

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: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152076 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74278

African (AFR) AF: 0.0000242 AC: 1 AN: 41390

American (AMR) AF: 0.00 AC: 0 AN: 15260

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5172

South Asian (SAS) AF: 0.00 AC: 0 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 867

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Transcobalamin II deficiency (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.59
CADD	Benign	19
DANN	Benign	0.70
PhyloP100		1.6

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.76		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.76		Position offset: 2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs35838082; hg19: chr22-31011350;