NM_004048.4:c.2T>A

Variant names:

• chr15-44711548-T-A
• NM_004048.4:c.2T>A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_004048.4(B2M):​c.2T>A​(p.Met1?) variant causes a start lost change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as other (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: B2M NM_004048.4 start_lost
• Clinical Significance: - - O:1
• Conservation: PhyloP100: 1.61

Genes affected

B2M (HGNC:914): (beta-2-microglobulin) This gene encodes a serum protein found in association with the major histocompatibility complex (MHC) class I heavy chain on the surface of nearly all nucleated cells. The protein has a predominantly beta-pleated sheet structure that can form amyloid fibrils in some pathological conditions. The encoded antimicrobial protein displays antibacterial activity in amniotic fluid. A mutation in this gene has been shown to result in hypercatabolic hypoproteinemia.[provided by RefSeq, Aug 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PVS1: Start lost variant, next in-frame start position is after 2 pathogenic variants. Next in-frame start position is after 354 CDS bases. Genomic position: 44716336. Lost 0.983 part of the original CDS.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
B2M	NM_004048.4	c.2T>A	p.Met1?	start_lost	Exon 1 of 4	ENST00000648006.3	NP_004039.1
B2M	XM_005254549.4	c.2T>A	p.Met1?	start_lost	Exon 1 of 2		XP_005254606.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
B2M	ENST00000648006.3	c.2T>A	p.Met1?	start_lost	Exon 1 of 4		NM_004048.4	ENSP00000497910.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: -

Submissions summary: Other:1

Revision: -

Submissions by phenotype

Neoplasm Other:1

-, criteria provided, single submitter

clinical testing

Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital

Mar 04, 2025

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Uncertain	0.040
CADD	Benign	22
DANN	Uncertain	0.98
DEOGEN2	Benign	0.11	T;D;D;D
Eigen	Benign	0.10
Eigen_PC	Benign	0.014
FATHMM_MKL	Uncertain	0.86	D
M_CAP	Uncertain	0.11	D
MetaRNN	Pathogenic	0.98	D;D;D;D
MetaSVM	Benign	-1.0	T
PROVEAN	Uncertain	-3.0	D;D;D;.
REVEL	Uncertain	0.29
Sift	Pathogenic	0.0	D;D;D;.
Sift4G	Pathogenic	0.0	D;D;D;.
Polyphen		0.98	D;D;D;D
Vest4		0.79
MutPred		0.89		Loss of stability (P = 0.0181);Loss of stability (P = 0.0181);Loss of stability (P = 0.0181);Loss of stability (P = 0.0181);
MVP		0.85
ClinPred		0.98	D
GERP RS		4.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.90
gMVP		0.78

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr15-45003746; COSMIC: COSV62563048; COSMIC: COSV62563048;