11-68938206-C-T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_002180.3(IGHMBP2):​c.2636C>T​(p.Thr879Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000246 in 1,461,754 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T879K) has been classified as Benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

IGHMBP2
NM_002180.3 missense

Scores

2
17

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: -0.292

Publications

43 publications found
Variant links:
Genes affected
IGHMBP2 (HGNC:5542): (immunoglobulin mu DNA binding protein 2) This gene encodes a helicase superfamily member that binds a specific DNA sequence from the immunoglobulin mu chain switch region. Mutations in this gene lead to spinal muscle atrophy with respiratory distress type 1. [provided by RefSeq, Jul 2008]
IGHMBP2 Gene-Disease associations (from GenCC):
  • autosomal recessive distal spinal muscular atrophy 1
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Genomics England PanelApp, Orphanet, Labcorp Genetics (formerly Invitae)
  • Charcot-Marie-Tooth disease axonal type 2S
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • hereditary peripheral neuropathy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.07715914).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
IGHMBP2NM_002180.3 linkc.2636C>T p.Thr879Met missense_variant Exon 14 of 15 ENST00000255078.8 NP_002171.2 P38935

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
IGHMBP2ENST00000255078.8 linkc.2636C>T p.Thr879Met missense_variant Exon 14 of 15 1 NM_002180.3 ENSP00000255078.4 P38935

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000517
AC:
13
AN:
251418
AF XY:
0.0000662
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000218
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000246
AC:
36
AN:
1461754
Hom.:
0
Cov.:
38
AF XY:
0.0000371
AC XY:
27
AN XY:
727208
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000756
AC:
3
AN:
39700
South Asian (SAS)
AF:
0.000232
AC:
20
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53292
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00000809
AC:
9
AN:
1112006
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.463
Heterozygous variant carriers
0
3
6
9
12
15
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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.:
32
Alfa
AF:
0.00
Hom.:
14826
ExAC
AF:
0.0000494
AC:
6

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive distal spinal muscular atrophy 1;C4015349:Charcot-Marie-Tooth disease axonal type 2S Uncertain:1
Jul 12, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 879 of the IGHMBP2 protein (p.Thr879Met). This variant is present in population databases (rs17612126, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with IGHMBP2-related conditions. ClinVar contains an entry for this variant (Variation ID: 1017770). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt IGHMBP2 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided Uncertain:1
Nov 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

IGHMBP2: PM2, BP4 -

Charcot-Marie-Tooth disease axonal type 2S Uncertain:1
-
Neuberg Centre For Genomic Medicine, NCGM
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The missense variant p.T879M in IGHMBP2 (NM_002180.2) has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. The p.T879M variant is observed in 7/30,616 (0.0229%) alleles from individuals of South Asian background in gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes. There is a moderate physicochemical difference between threonine and methionine. The p.T879M missense variant is predicted to be tolerated by both SIFT or PolyPhen2. The nucleotide c.2636 in IGHMBP2 is not conserved according to a GERP++ and PhyloP analysis of 100 vertebrates. For these reasons, this variant has been classified as Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.072
BayesDel_addAF
Benign
-0.30
T
BayesDel_noAF
Benign
-0.37
CADD
Benign
7.1
DANN
Uncertain
0.98
DEOGEN2
Benign
0.13
T
Eigen
Benign
-0.83
Eigen_PC
Benign
-1.0
FATHMM_MKL
Benign
0.028
N
LIST_S2
Benign
0.41
T
M_CAP
Benign
0.029
D
MetaRNN
Benign
0.077
T
MetaSVM
Benign
-0.41
T
MutationAssessor
Benign
1.2
L
PhyloP100
-0.29
PrimateAI
Benign
0.23
T
PROVEAN
Benign
-0.79
N
REVEL
Uncertain
0.34
Sift
Benign
0.079
T
Sift4G
Benign
0.11
T
Polyphen
0.91
P
Vest4
0.13
MutPred
0.13
Loss of glycosylation at T879 (P = 0.0105);
MVP
0.81
MPC
0.35
ClinPred
0.41
T
GERP RS
-3.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.023
gMVP
0.18
Mutation Taster
=97/3
polymorphism

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

Other links and lift over

dbSNP: rs17612126; hg19: chr11-68705674; COSMIC: COSV105040982; COSMIC: COSV105040982; API