NM_016579.4:c.769_771delGAGinsAAA

Variant names:

• chr19-8302541-CTC-TTT
• NM_016579.4:c.769_771delGAGinsAAA
• CD320 p.Glu257Lys

Variant summary

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

The NM_016579.4(CD320):​c.769_771delGAGinsAAA​(p.Glu257Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CD320 NM_016579.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0210
• Publications: 0 publications found

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)

ACMG classification

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

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.769_771delGAGinsAAA	p.Glu257Lys	missense	N/A	NP_057663.1	Q9NPF0-1
	CD320	NM_001165895.2		c.643_645delGAGinsAAA	p.Glu215Lys	missense	N/A	NP_001159367.1	Q9NPF0-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CD320	ENST00000301458.10	TSL:1 MANE Select	c.769_771delGAGinsAAA	p.Glu257Lys	missense	N/A	ENSP00000301458.4	Q9NPF0-1
	CD320	ENST00000596002.5	TSL:1	n.*1057_*1059delGAGinsAAA		non_coding_transcript_exon	Exon 5 of 5	ENSP00000471773.1	M0R1C4
	CD320	ENST00000596002.5	TSL:1	n.*1057_*1059delGAGinsAAA		3_prime_UTR	Exon 5 of 5	ENSP00000471773.1	M0R1C4

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.021

Splicing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr19-8367425;