chr11-68903956-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1PM2BP4

The NM_002180.3(IGHMBP2):​c.4G>T​(p.Ala2Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000894 in 1,566,356 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 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. A2T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 35)
Exomes 𝑓: 0.0000028 ( 0 hom. )

Consequence

IGHMBP2
NM_002180.3 missense

Scores

1
4
14

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 2.80
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM1
In a modified_residue N-acetylalanine (size 0) in uniprot entity SMBP2_HUMAN
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.34026277).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
IGHMBP2NM_002180.3 linkuse as main transcriptc.4G>T p.Ala2Ser missense_variant 1/15 ENST00000255078.8
IGHMBP2XM_047426881.1 linkuse as main transcriptc.4G>T p.Ala2Ser missense_variant 1/15
IGHMBP2XM_017017671.3 linkuse as main transcriptc.4G>T p.Ala2Ser missense_variant 1/12
IGHMBP2XM_005273976.3 linkuse as main transcriptc.4G>T p.Ala2Ser missense_variant 1/9

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
IGHMBP2ENST00000255078.8 linkuse as main transcriptc.4G>T p.Ala2Ser missense_variant 1/151 NM_002180.3 P1

Frequencies

GnomAD3 genomes
AF:
0.0000657
AC:
10
AN:
152246
Hom.:
0
Cov.:
35
show subpopulations
Gnomad AFR
AF:
0.000217
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.000288
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000583
AC:
1
AN:
171622
Hom.:
0
AF XY:
0.0000108
AC XY:
1
AN XY:
92358
show subpopulations
Gnomad AFR exome
AF:
0.000104
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000283
AC:
4
AN:
1414110
Hom.:
0
Cov.:
44
AF XY:
0.00000429
AC XY:
3
AN XY:
699612
show subpopulations
Gnomad4 AFR exome
AF:
0.000124
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:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000657
AC:
10
AN:
152246
Hom.:
0
Cov.:
35
AF XY:
0.0000403
AC XY:
3
AN XY:
74382
show subpopulations
Gnomad4 AFR
AF:
0.000217
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.000288
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000604

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsMar 14, 2023The c.4G>T (p.A2S) alteration is located in exon 1 (coding exon 1) of the IGHMBP2 gene. This alteration results from a G to T substitution at nucleotide position 4, causing the alanine (A) at amino acid position 2 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Autosomal recessive distal spinal muscular atrophy 1;C4015349:Charcot-Marie-Tooth disease axonal type 2S Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingInvitaeAug 30, 2021This sequence change replaces alanine with serine at codon 2 of the IGHMBP2 protein (p.Ala2Ser). The alanine residue is weakly conserved and there is a moderate physicochemical difference between alanine and serine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with IGHMBP2-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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
Benign
0.078
BayesDel_addAF
Benign
-0.054
T
BayesDel_noAF
Benign
-0.090
CADD
Benign
20
DANN
Uncertain
0.99
DEOGEN2
Benign
0.057
T;.
Eigen
Benign
-0.20
Eigen_PC
Benign
-0.10
FATHMM_MKL
Benign
0.18
N
LIST_S2
Benign
0.65
T;T
M_CAP
Pathogenic
0.41
D
MetaRNN
Benign
0.34
T;T
MetaSVM
Uncertain
0.045
D
MutationAssessor
Uncertain
2.3
M;.
MutationTaster
Benign
0.67
D;D
PrimateAI
Uncertain
0.72
T
PROVEAN
Benign
-0.31
N;N
REVEL
Benign
0.21
Sift
Benign
0.053
T;T
Sift4G
Benign
0.45
T;T
Polyphen
0.068
B;.
Vest4
0.23
MutPred
0.10
Gain of phosphorylation at A2 (P = 0.0273);Gain of phosphorylation at A2 (P = 0.0273);
MVP
0.91
MPC
0.18
ClinPred
0.61
D
GERP RS
3.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.6
Varity_R
0.079
gMVP
0.62

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

LitVar

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

Other links and lift over

dbSNP: rs778232785; hg19: chr11-68671424; API