rs1378524388

Positions:

• chr11-68935386-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 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

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 Likely_pathogenic. Variant got 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, 7 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/exons	MANE	UniProt
IGHMBP2	NM_002180.3	c.1720G>A	p.Ala574Thr	missense_variant	12/15	ENST00000255078.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IGHMBP2	ENST00000255078.8	c.1720G>A	p.Ala574Thr	missense_variant	12/15	1	NM_002180.3	P1

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

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

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

Uncertain significance, criteria provided, single submitter

case-control

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

Jan 21, 2018

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
MutationTaster	Benign	1.0	D
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

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

Other links and lift over

dbSNP: rs1378524388; hg19: chr11-68702854;