rs200072932

Positions:

• chr11-68936936-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_002180.3(IGHMBP2):​c.2456C>T​(p.Pro819Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000374 in 1,604,092 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. P819P) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: IGHMBP2 NM_002180.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.455

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_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.03129822).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IGHMBP2	NM_002180.3	c.2456C>T	p.Pro819Leu	missense_variant	13/15	ENST00000255078.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IGHMBP2	ENST00000255078.8	c.2456C>T	p.Pro819Leu	missense_variant	13/15	1	NM_002180.3	P1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152232 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000965

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: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000133 AC: 3 AN: 226094 Hom.: 0 AF XY: 0.0000243 AC XY: 3 AN XY: 123380

Gnomad AFR exome AF: 0.000220

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000138 AC: 2 AN: 1451742 Hom.: 0 Cov.: 35 AF XY: 0.00000277 AC XY: 2 AN XY: 721422

Gnomad4 AFR exome AF: 0.0000600

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152350 Hom.: 0 Cov.: 33 AF XY: 0.0000403 AC XY: 3 AN XY: 74514

Gnomad4 AFR AF: 0.0000962

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: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000151

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Invitae

Jun 15, 2018

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The leucine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with IGHMBP2-related disease. This variant is present in population databases (rs200072932, ExAC 0.03%). This sequence change replaces proline with leucine at codon 819 of the IGHMBP2 protein (p.Pro819Leu). The proline residue is weakly conserved and there is a moderate physicochemical difference between proline and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.066
BayesDel_addAF	Benign	-0.34	T
BayesDel_noAF	Benign	-0.44
CADD	Benign	0.26
DANN	Benign	0.60
DEOGEN2	Benign	0.098	T
Eigen	Benign	-1.8
Eigen_PC	Benign	-1.9
FATHMM_MKL	Benign	0.017	N
LIST_S2	Benign	0.45	T
M_CAP	Benign	0.055	D
MetaRNN	Benign	0.031	T
MetaSVM	Benign	-0.60	T
MutationAssessor	Benign	0.74	N
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.37	T
PROVEAN	Benign	-1.9	N
REVEL	Benign	0.21
Sift	Benign	0.24	T
Sift4G	Benign	0.33	T
Polyphen		0.0	B
Vest4		0.065
MVP		0.45
MPC		0.20
ClinPred		0.030	T
GERP RS		-8.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.054
gMVP		0.16

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: rs200072932; hg19: chr11-68704404;