rs746581714

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_002180.3(IGHMBP2):c.983_987delAAGAA(p.Lys328ThrfsTer46) variant causes a frameshift change. The variant allele was found at a frequency of 0.0000316 in 1,613,684 control chromosomes in the GnomAD database, with no homozygous occurrence. 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: 0.000032 ( 0 hom. )

Consequence

IGHMBP2
NM_002180.3 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6U:2

Conservation

PhyloP100: 6.24

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 was made for transcript

Our verdict: Pathogenic. The variant received 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 11-68917800-TAAGAA-T is Pathogenic according to our data. Variant chr11-68917800-TAAGAA-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 217449.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-68917800-TAAGAA-T is described in Lovd as [Pathogenic]. Variant chr11-68917800-TAAGAA-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.983_987delAAGAA	p.Lys328ThrfsTer46	frameshift_variant	Exon 7 of 15	ENST00000255078.8	NP_002171.2	P38935

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IGHMBP2	ENST00000255078.8 link	c.983_987delAAGAA	p.Lys328ThrfsTer46	frameshift_variant	Exon 7 of 15	1	NM_002180.3	ENSP00000255078.4		P38935

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152182

Hom.:

Cov.:

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:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000795

AC:

AN:

251488

AF XY:

0.00000736

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:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000322

AC:

AN:

1461502

Hom.:

AF XY:

0.0000289

AC XY:

AN XY:

727102

show subpopulations

Gnomad4 AFR exome

AF:

0.00

AC:

AN:

33470

Gnomad4 AMR exome

AF:

0.00

AC:

AN:

44722

Gnomad4 ASJ exome

AF:

0.00

AC:

AN:

26134

Gnomad4 EAS exome

AF:

0.00

AC:

AN:

39700

Gnomad4 SAS exome

AF:

0.00

AC:

AN:

86252

Gnomad4 FIN exome

AF:

0.00

AC:

AN:

53418

Gnomad4 NFE exome

AF:

0.0000387

AC:

AN:

1111680

Gnomad4 Remaining exome

AF:

0.0000663

AC:

AN:

60372

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Exome Het

Variant carriers

<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:

0.0000263

AC:

AN:

152182

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74352

show subpopulations

Gnomad4 AFR

AF:

0.00

AC:

AN:

Gnomad4 AMR

AF:

0.00

AC:

AN:

Gnomad4 ASJ

AF:

0.00

AC:

AN:

Gnomad4 EAS

AF:

0.00

AC:

AN:

Gnomad4 SAS

AF:

0.00

AC:

AN:

Gnomad4 FIN

AF:

0.00

AC:

AN:

Gnomad4 NFE

AF:

0.0000588

AC:

0.0000588028

AN:

0.0000588028

Gnomad4 OTH

AF:

0.00

AC:

AN:

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Genome Het

Variant carriers

<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:

0.0000712

Hom.:

Bravo

AF:

0.0000264

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6Uncertain:2

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

Pathogenic:2

Jun 18, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 24, 2024

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.Lys328Thrfs*46) 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 (rs746581714, gnomAD 0.002%). This premature translational stop signal has been observed in individual(s) with Charcot-Marie-Tooth (CMT) disease and spinal muscular atrophy with respiratory distress (SMARD1) (PMID: 14681881, 27450922). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 217449). For these reasons, this variant has been classified as Pathogenic. -

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 frameshifting variant in exon 7 of 15 introduces a premature stop codon and is therefore 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 heterozygous, homozygous, and compound heterozygous change in patients with sensorimotor axonal neuropathy/ infantile spinal muscular atrophy with or without respiratory failure (PMID: 27450922, 14681881). Loss-of-function variation in IGHMBP2 is an established mechanism of disease (PMID: 14681881, 25439726, 25568292). The c.983_987del (p.Lys328ThrfsTer46) variant is present in the heterozygous state in the gnomAD population database at a frequency of 0.001% (3/282884) and is absent in the homozygous state, thus is presumed to be rare. Based on the available evidence, the c.983_987del (p.Lys328ThrfsTer46) variant is classified as Likely Pathogenic. -

Autosomal recessive distal spinal muscular atrophy 1

Pathogenic:1

Oct 21, 2015

Department of Medical Genetics, Oslo University Hospital

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

- -

not provided

Pathogenic:1

Aug 23, 2022

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Frameshift 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 a significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 14681881, 27450922, 31980526) -

Charcot-Marie-Tooth disease axonal type 2S

Pathogenic:1

Oct 21, 2015

Department of Medical Genetics, Oslo University Hospital

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

- -

Charcot-Marie-Tooth disease

Uncertain:1

Aug 14, 2019

Genesis Genome Database

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:research

- -

Neuronopathy, distal hereditary motor, autosomal dominant

Uncertain:1

Inherited Neuropathy Consortium

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Mutation Taster

=0/200

disease causing (ClinVar)

Splicing

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