11-68933499-A-C

Variant names:

• chr11-68933499-A-C
• rs112575423
• NM_002180.3:c.1418+18A>C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_002180.3(IGHMBP2):​c.1418+18A>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000689 in 1,451,270 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: IGHMBP2 NM_002180.3 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -4.04
• Publications: 2 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_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.94).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002180.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IGHMBP2	NM_002180.3	MANE Select	c.1418+18A>C		intron	N/A	NP_002171.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IGHMBP2	ENST00000255078.8	TSL:1 MANE Select	c.1418+18A>C		intron	N/A	ENSP00000255078.4
	IGHMBP2	ENST00000925063.1		c.1236-296A>C		intron	N/A	ENSP00000595122.1
	IGHMBP2	ENST00000675615.1		c.1418+18A>C		intron	N/A	ENSP00000502413.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.89e-7 AC: 1 AN: 1451270 Hom.: 0 Cov.: 32 AF XY: 0.00000139 AC XY: 1 AN XY: 721100

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33322

American (AMR) AF: 0.00 AC: 0 AN: 43540

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25866

East Asian (EAS) AF: 0.00 AC: 0 AN: 39310

South Asian (SAS) AF: 0.00 AC: 0 AN: 84674

European-Finnish (FIN) AF: 0.0000194 AC: 1 AN: 51472

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5750

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1107360

Other (OTH) AF: 0.00 AC: 0 AN: 59976

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.94
CADD	Benign	0.14
DANN	Benign	0.30
PhyloP100		-4.0

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: rs112575423; hg19: chr11-68700967;