rs764111837

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PP3_ModeratePP5

The NM_002180.3(IGHMBP2):​c.1489G>A​(p.Gly497Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000106 in 1,606,110 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G497W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

IGHMBP2
NM_002180.3 missense

Scores

7
10
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1

Conservation

PhyloP100: 9.04

Publications

2 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_pathogenic. The variant received 7 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 4 uncertain in NM_002180.3
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.864
PP5
Variant 11-68933865-G-A is Pathogenic according to our data. Variant chr11-68933865-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 836364.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
IGHMBP2NM_002180.3 linkc.1489G>A p.Gly497Arg missense_variant Exon 10 of 15 ENST00000255078.8 NP_002171.2 P38935

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
IGHMBP2ENST00000255078.8 linkc.1489G>A p.Gly497Arg missense_variant Exon 10 of 15 1 NM_002180.3 ENSP00000255078.4 P38935

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152190
Hom.:
0
Cov.:
33
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:
0.000188
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000258
AC:
6
AN:
232962
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000101
Gnomad NFE exome
AF:
0.0000384
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000963
AC:
14
AN:
1453920
Hom.:
0
Cov.:
31
AF XY:
0.00000969
AC XY:
7
AN XY:
722518
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33374
American (AMR)
AF:
0.00
AC:
0
AN:
43562
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25932
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39440
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84762
European-Finnish (FIN)
AF:
0.000151
AC:
8
AN:
52874
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5756
European-Non Finnish (NFE)
AF:
0.00000451
AC:
5
AN:
1108184
Other (OTH)
AF:
0.0000167
AC:
1
AN:
60036
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.493
Heterozygous variant carriers
0
1
2
2
3
4
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
AF:
0.0000197
AC:
3
AN:
152190
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74356
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.000188
AC:
2
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.442
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:1
Dec 13, 2023
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 24388491, 25439726, 22965130, 28065684) -

Autosomal recessive distal spinal muscular atrophy 1;C4015349:Charcot-Marie-Tooth disease axonal type 2S Uncertain:1
Aug 28, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine with arginine at codon 497 of the IGHMBP2 protein (p.Gly497Arg). The glycine residue is moderately conserved and there is a moderate physicochemical difference between glycine and arginine. This variant is present in population databases (rs764111837, ExAC 0.005%). This missense change has been observed in individual(s) with Charcot-Marie-Tooth disease, type 2 (PMID: 28065684). In at least one individual the data is consistent with the variant being in trans (on the opposite chromosome) from a pathogenic variant. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.56
BayesDel_addAF
Uncertain
0.12
D
BayesDel_noAF
Uncertain
0.010
CADD
Pathogenic
29
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.64
D
Eigen
Pathogenic
0.72
Eigen_PC
Pathogenic
0.67
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
D
M_CAP
Uncertain
0.20
D
MetaRNN
Pathogenic
0.86
D
MetaSVM
Uncertain
0.29
D
MutationAssessor
Benign
2.0
M
PhyloP100
9.0
PrimateAI
Uncertain
0.73
T
PROVEAN
Uncertain
-3.8
D
REVEL
Pathogenic
0.68
Sift
Uncertain
0.016
D
Sift4G
Uncertain
0.021
D
Polyphen
1.0
D
Vest4
0.82
MutPred
0.44
Gain of sheet (P = 0.0477);
MVP
0.95
MPC
0.82
ClinPred
0.95
D
GERP RS
4.8
Varity_R
0.70
gMVP
0.85
Mutation Taster
=35/65
disease causing

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: rs764111837; hg19: chr11-68701333; API