Genetic Variant IGHMBP2:c.-34C>T (chr11-68903919-C-T) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_002180.3(IGHMBP2):c.-34C>T 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 0.0000169 in 1,599,544 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: 𝑓 0.000039 ( 0 hom., cov: 35)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

IGHMBP2
NM_002180.3 5_prime_UTR_premature_start_codon_gain

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: -1.97

Variant links:

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 links:

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]

MRPL21 links:

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ACMG classification

Classification made for transcript

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=-0.96).

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	Exon rank	MANE	Protein	UniProt
IGHMBP2	NM_002180.3 link	c.-34C>T	5_prime_UTR_premature_start_codon_gain_variant	Exon 1 of 15	ENST00000255078.8	NP_002171.2	P38935
IGHMBP2	NM_002180.3 link	c.-34C>T	5_prime_UTR_variant	Exon 1 of 15	ENST00000255078.8	NP_002171.2	P38935
MRPL21	NM_181514.2 link	c.-109G>A	upstream_gene_variant		ENST00000362034.7	NP_852615.1	Q7Z2W9-1

Ensembl

Gene	Transcript	HGVSc	Effect	Exon rank	TSL	MANE	Protein	UniProt
IGHMBP2	ENST00000255078 link	c.-34C>T	5_prime_UTR_premature_start_codon_gain_variant	Exon 1 of 15	1	NM_002180.3	ENSP00000255078.4	P38935
IGHMBP2	ENST00000255078 link	c.-34C>T	5_prime_UTR_variant	Exon 1 of 15	1	NM_002180.3	ENSP00000255078.4	P38935
MRPL21	ENST00000362034.7 link	c.-109G>A	upstream_gene_variant		1	NM_181514.2	ENSP00000354580.2	Q7Z2W9-1

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152216

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

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:

0.000955

GnomAD3 exomes

AF:

0.0000598

AC:

AN:

217544

Hom.:

AF XY:

0.0000335

AC XY:

AN XY:

119302

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000378

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:

0.0000106

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000145

AC:

AN:

1447328

Hom.:

Cov.:

AF XY:

0.00000973

AC XY:

AN XY:

719156

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000351

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000118

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000362

Gnomad4 OTH exome

AF:

0.0000167

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152216

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74366

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.000196

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:

0.000955

Bravo

AF:

0.0000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.96

CADD

Benign

5.5

DANN

Benign

0.87

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Computational scores

Splicing

Publications

LitVar

Other links and lift over