rs1378524388

Variant names:

• chr11-68935386-G-A
• rs1378524388
• NM_002180.3:c.1720G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_002180.3(IGHMBP2):​c.1720G>A​(p.Ala574Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,776 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 Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. A574A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: IGHMBP2 NM_002180.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.42
• Publications: 1 publications found

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_002180.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.884

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IGHMBP2	NM_002180.3	c.1720G>A	p.Ala574Thr	missense_variant	Exon 12 of 15	ENST00000255078.8	NP_002171.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IGHMBP2	ENST00000255078.8	c.1720G>A	p.Ala574Thr	missense_variant	Exon 12 of 15	1	NM_002180.3	ENSP00000255078.4

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461776 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727198

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53310

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1112006

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 34

Alfa AF: 0.0000387 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Autosomal recessive distal spinal muscular atrophy 1 Uncertain:1

Jan 21, 2018

Service de Pédiatrie - Neurologie et infectiologie - Toulouse, CHU de Toulouse - Hôpital des Enfants

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: case-control

Well conserved across species. Never published yet. Missense mutation in the end of the main functional domain of IGHMBP2 "DNA helicase" in the region 2A where ATP binding sites seem to be concentrated. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.33
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.18
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.71	D
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D
M_CAP	Uncertain	0.27	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.6	M
PhyloP100		9.4
PrimateAI	Uncertain	0.63	T
PROVEAN	Uncertain	-3.1	D
REVEL	Pathogenic	0.79
Sift	Uncertain	0.020	D
Sift4G	Uncertain	0.012	D
Polyphen		1.0	D
Vest4		0.78
MutPred		0.45		Loss of ubiquitination at K572 (P = 0.1216);
MVP		0.97
MPC		0.74
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.91
gMVP		0.75
Mutation Taster		=6/94	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

Other links and lift over

dbSNP: rs1378524388; hg19: chr11-68702854;