chr11-68903928-C-G

Variant names:

• chr11-68903928-C-G
• NM_002180.3:c.-25C>G

Variant summary

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

The NM_002180.3(IGHMBP2):​c.-25C>G variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000693 in 1,443,374 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: 35)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: IGHMBP2 NM_002180.3 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.216

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]

MRPL21 (HGNC:14479): (mitochondrial ribosomal protein L21) Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and help in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. They have an estimated 75% protein to rRNA composition compared to prokaryotic ribosomes, where this ratio is reversed. Another difference between mammalian mitoribosomes and prokaryotic ribosomes is that the latter contain a 5S rRNA. Among different species, the proteins comprising the mitoribosome differ greatly in sequence, and sometimes in biochemical properties, which prevents easy recognition by sequence homology. This gene encodes a 39S subunit protein. Multiple transcript variants encoding different isoforms were identified through sequence analysis although some may be subject to nonsense-mediated decay (NMD). [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 (BayesDel_noAF=-0.99).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IGHMBP2	NM_002180.3	c.-25C>G		5_prime_UTR_premature_start_codon_gain_variant	Exon 1 of 15	ENST00000255078.8	NP_002171.2
IGHMBP2	NM_002180.3	c.-25C>G		5_prime_UTR_variant	Exon 1 of 15	ENST00000255078.8	NP_002171.2
MRPL21	NM_181514.2	c.-118G>C		upstream_gene_variant		ENST00000362034.7	NP_852615.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IGHMBP2	ENST00000255078	c.-25C>G		5_prime_UTR_premature_start_codon_gain_variant	Exon 1 of 15	1	NM_002180.3	ENSP00000255078.4
IGHMBP2	ENST00000255078	c.-25C>G		5_prime_UTR_variant	Exon 1 of 15	1	NM_002180.3	ENSP00000255078.4
MRPL21	ENST00000362034.7	c.-118G>C		upstream_gene_variant		1	NM_181514.2	ENSP00000354580.2

Frequencies

GnomAD3 genomes Cov.: 35

GnomAD4 exome AF: 6.93e-7 AC: 1 AN: 1443374 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 716668

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: 9.06e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 35

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.99
CADD	Benign	7.4
DANN	Benign	0.52
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr11-68671396;