11-68914845-A-G

Position:

• chr11-68914845-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_002180.3(IGHMBP2):​c.734A>G​(p.Asn245Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: IGHMBP2 NM_002180.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:3
• Conservation: PhyloP100: 8.48

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.916

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
IGHMBP2	NM_002180.3	c.734A>G	p.Asn245Ser	missense_variant	6/15	ENST00000255078.8	NP_002171.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IGHMBP2	ENST00000255078.8	c.734A>G	p.Asn245Ser	missense_variant	6/15	1	NM_002180.3	ENSP00000255078	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease Uncertain:1

Uncertain significance, no assertion criteria provided

literature only

Inherited Neuropathy Consortium

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 12, 2021

This sequence change replaces asparagine with serine at codon 245 of the IGHMBP2 protein (p.Asn245Ser). The asparagine residue is moderately conserved and there is a small physicochemical difference between asparagine and serine. This variant is not present in population databases (ExAC no frequency). This missense change has been observed in individual(s) with Charcot-Marie-Tooth (CMT) disease type 2 and gait difficulty (PMID: 25439726, 26922252; Invitae). 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: "Tolerated"; 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. -

Charcot-Marie-Tooth disease, type I Uncertain:1

Uncertain significance, no assertion criteria provided

research

Genesis Genome Database

Aug 14, 2019

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.36
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.0
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.91	D
Eigen	Uncertain	0.68
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.36	D
MetaRNN	Pathogenic	0.92	D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	4.0	H
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.56	T
PROVEAN	Pathogenic	-4.8	D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.87
MutPred		0.54		Loss of loop (P = 0.2897);
MVP		0.98
MPC		0.67
ClinPred		1.0	D
GERP RS		3.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.95
gMVP		0.82

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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

Other links and lift over

dbSNP: rs1555243999; hg19: chr11-68682313;