chr11-68906109-C-T

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_002180.3(IGHMBP2):c.127C>T(p.Arg43*) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000434 in 1,614,046 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000045 ( 0 hom. )

Consequence

IGHMBP2
NM_002180.3 stop_gained

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 4.58

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 11-68906109-C-T is Pathogenic according to our data. Variant chr11-68906109-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 228355.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-68906109-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IGHMBP2	NM_002180.3 link	c.127C>T	p.Arg43*	stop_gained	Exon 2 of 15	ENST00000255078.8	NP_002171.2	P38935
IGHMBP2	XM_047426881.1 link	c.127C>T	p.Arg43*	stop_gained	Exon 2 of 15		XP_047282837.1
IGHMBP2	XM_017017671.3 link	c.127C>T	p.Arg43*	stop_gained	Exon 2 of 12		XP_016873160.1
IGHMBP2	XM_005273976.3 link	c.127C>T	p.Arg43*	stop_gained	Exon 2 of 9		XP_005274033.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IGHMBP2	ENST00000255078.8 link	c.127C>T	p.Arg43*	stop_gained	Exon 2 of 15	1	NM_002180.3	ENSP00000255078.4		P38935

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152172

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000318

AC:

AN:

251482

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135908

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 SAS exome

AF:

0.0000980

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000440

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000451

AC:

AN:

1461874

Hom.:

Cov.:

AF XY:

0.0000426

AC XY:

AN XY:

727238

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:

0.000162

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000450

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152172

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74346

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000248

Hom.:

Bravo

AF:

0.0000264

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.0000412

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:4

Sep 20, 2016

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 01, 2016

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 13, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 14506069) -

Dec 15, 2023

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is expected to result in the loss of a functional protein. The frequency of this variant in the general population is consistent with pathogenicity. (http://gnomad.broadinstitute.org) This variant has been identified in at least one individual with autosomal recessive distal hereditary motor neuropathy. -

IGHMBP2-related disorder

Pathogenic:1

Rady Children's Institute for Genomic Medicine, Rady Children's Hospital San Diego

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This nonsense variant found in exon 2 of 15 is predicted to result in loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay (NMD). This variant has been previously reported as a compound heterozygous change in a patient with early onset diaphragmatic palsy in association with a progressive neuropathy (PMID: 14506069). Loss-of-function variation in IGHMBP2 is an established mechanism of disease (PMID: 14681881, 25439726, 25568292). The c.127C>T (p.Arg43Ter) variant is present in the heterozygous state in the gnomAD population database at a frequency of 0.003% (10/282866) and is absent in the homozygous state, thus is presumed to be rare. Based on the available evidence, the c.127C>T (p.Arg43Ter) variant is classified as Pathogenic. -

Distal spinal muscular atrophy

Pathogenic:1

Mar 11, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Arg43X variant in IGHMBP2 has been previously reported in one compound het erozygous individual with spinal muscular atrophy with respiratory distress (SMA RD1; Pitt 2003). It has also been identified in 0.01% (5/66736) European chromos omes by the Exome Aggregation Consortium (http://exac.broadinstitute.org; dbSNP rs200089714). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. Th is nonsense variant leads to a premature termination codon at position 43, which is predicted to lead to a truncated or absent protein. Complete loss of IGHMBP2 function is an established disease mechanism for SMARD1. In summary, this varia nt meets our criteria to be classified as pathogenic for SMARD1 in an autosomal recessive manner (www.partners.org/personalizedmedicine/lmm). -

Autosomal recessive distal spinal muscular atrophy 1;C4015349:Charcot-Marie-Tooth disease axonal type 2S

Pathogenic:1

Jan 13, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg43*) in the IGHMBP2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in IGHMBP2 are known to be pathogenic (PMID: 14681881, 25439726, 25568292). This variant is present in population databases (rs200089714, gnomAD 0.01%). This premature translational stop signal has been observed in individual(s) with severe infantile neuropathy with diaphragmatic weakness (PMID: 14506069). ClinVar contains an entry for this variant (Variation ID: 228355). For these reasons, this variant has been classified as Pathogenic. -

Autosomal recessive distal spinal muscular atrophy 1

Pathogenic:1

Neuberg Centre For Genomic Medicine, NCGM

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The observed stop gained variant c.127C>T(p.Arg43Ter) in IGHMBP2 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. The c.127C>T(p.Arg43Ter) variant is reported with 0.003% allele frequency in gnomAD Exomes. It has been submitted to ClinVar as Pathogenic (multiple submitters). Computational evidence (Mutation Taster - Disease causing) predicts damaging effect on protein structure and function for this variant.This variant is predicted to cause loss of normal protein function through protein truncation. Loss of function variants have been previously reported to be disease causing. For these reasons, this variant has been classified as Likely Pathogenic. In the absence of another reportable variant, the molecular diagnosis is not confirmed. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.48

BayesDel_noAF

Pathogenic

0.46

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.59

Eigen_PC

Uncertain

0.39

FATHMM_MKL

Benign

0.70

Vest4

0.89

GERP RS

2.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.12

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over