12-9077348-T-G

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_000014.6(A2M):ā€‹c.3349A>Cā€‹(p.Thr1117Pro) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,612,658 control chromosomes in the GnomAD database, with no homozygous occurrence. 13/23 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (ā˜…).

Frequency

Genomes: š‘“ 0.0000066 ( 0 hom., cov: 32)
Exomes š‘“: 0.0000075 ( 0 hom. )

Consequence

A2M
NM_000014.6 missense, splice_region

Scores

2
5
12
Splicing: ADA: 0.007091
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.37
Variant links:
Genes affected
A2M (HGNC:7): (alpha-2-macroglobulin) The protein encoded by this gene is a protease inhibitor and cytokine transporter. It uses a bait-and-trap mechanism to inhibit a broad spectrum of proteases, including trypsin, thrombin and collagenase. It can also inhibit inflammatory cytokines, and it thus disrupts inflammatory cascades. Mutations in this gene are a cause of alpha-2-macroglobulin deficiency. This gene is implicated in Alzheimer's disease (AD) due to its ability to mediate the clearance and degradation of A-beta, the major component of beta-amyloid deposits. A related pseudogene, which is also located on the p arm of chromosome 12, has been identified. [provided by RefSeq, Nov 2016]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BS2
High AC in GnomAdExome4 at 11 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
A2MNM_000014.6 linkuse as main transcriptc.3349A>C p.Thr1117Pro missense_variant, splice_region_variant 27/36 ENST00000318602.12

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
A2MENST00000318602.12 linkuse as main transcriptc.3349A>C p.Thr1117Pro missense_variant, splice_region_variant 27/361 NM_000014.6 P1
A2MENST00000543436.2 linkuse as main transcriptn.452-9536A>C intron_variant, non_coding_transcript_variant 5
A2MENST00000545828.1 linkuse as main transcriptn.349-4627A>C intron_variant, non_coding_transcript_variant 4

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152160
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:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000753
AC:
11
AN:
1460498
Hom.:
0
Cov.:
31
AF XY:
0.00000688
AC XY:
5
AN XY:
726478
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000990
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152160
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74328
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000329
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsApr 17, 2024The c.3349A>C (p.T1117P) alteration is located in exon 27 (coding exon 27) of the A2M gene. This alteration results from a A to C substitution at nucleotide position 3349, causing the threonine (T) at amino acid position 1117 to be replaced by a proline (P). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Benign
-0.080
T
BayesDel_noAF
Benign
-0.35
CADD
Benign
23
DANN
Uncertain
0.99
DEOGEN2
Benign
0.19
T
Eigen
Benign
0.070
Eigen_PC
Benign
-0.058
FATHMM_MKL
Uncertain
0.89
D
LIST_S2
Benign
0.64
T
M_CAP
Benign
0.034
D
MetaRNN
Uncertain
0.49
T
MetaSVM
Benign
-0.94
T
MutationAssessor
Pathogenic
3.0
M
MutationTaster
Benign
0.84
N
PrimateAI
Benign
0.38
T
PROVEAN
Pathogenic
-5.2
D
REVEL
Benign
0.12
Sift
Uncertain
0.0020
D
Sift4G
Uncertain
0.014
D
Polyphen
0.99
D
Vest4
0.36
MutPred
0.51
Loss of catalytic residue at T1117 (P = 0.0494);
MVP
0.80
MPC
0.37
ClinPred
0.83
D
GERP RS
2.0
Varity_R
0.74
gMVP
0.67

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.0071
dbscSNV1_RF
Benign
0.12
SpliceAI score (max)
0.10
Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs1478250854; hg19: chr12-9229944; API