NM_002180.3:c.15T>A

Variant names:

• chr11-68903967-T-A
• rs1318640024
• NM_002180.3:c.15T>A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 2P and 7B. PM2 BP4_Strong BP6_Moderate BP7

The NM_002180.3(IGHMBP2):​c.15T>A​(p.Ala5Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000128 in 1,559,628 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 35)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: IGHMBP2 NM_002180.3 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -4.06
• 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]

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

Our verdict: Likely_benign. The variant received -5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.88).
• BP6: Variant 11-68903967-T-A is Benign according to our data. Variant chr11-68903967-T-A is described in ClinVar as [Likely_benign]. Clinvar id is 2935675.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-4.06 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IGHMBP2	NM_002180.3	c.15T>A	p.Ala5Ala	synonymous_variant	Exon 1 of 15	ENST00000255078.8	NP_002171.2
MRPL21	NM_181514.2	c.-157A>T		upstream_gene_variant		ENST00000362034.7	NP_852615.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IGHMBP2	ENST00000255078.8	c.15T>A	p.Ala5Ala	synonymous_variant	Exon 1 of 15	1	NM_002180.3	ENSP00000255078.4
MRPL21	ENST00000362034.7	c.-157A>T		upstream_gene_variant		1	NM_181514.2	ENSP00000354580.2

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152034 Hom.: 0 Cov.: 35

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000194

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

GnomAD2 exomes AF: 0.00000610 AC: 1 AN: 163990 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000844

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 7.10e-7 AC: 1 AN: 1407594 Hom.: 0 Cov.: 43 AF XY: 0.00 AC XY: 0 AN XY: 695656

African (AFR) AF: 0.00 AC: 0 AN: 31940

American (AMR) AF: 0.00 AC: 0 AN: 36360

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25244

East Asian (EAS) AF: 0.0000275 AC: 1 AN: 36360

South Asian (SAS) AF: 0.00 AC: 0 AN: 81016

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48598

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5690

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1084078

Other (OTH) AF: 0.00 AC: 0 AN: 58308

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152034 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 74270

African (AFR) AF: 0.00 AC: 0 AN: 41408

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.000194 AC: 1 AN: 5142

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67974

Other (OTH) AF: 0.00 AC: 0 AN: 2088

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Autosomal recessive distal spinal muscular atrophy 1;C4015349:Charcot-Marie-Tooth disease axonal type 2S Benign:1

Oct 04, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.88
CADD	Benign	0.48
DANN	Benign	0.88
PhyloP100		-4.1
PromoterAI		0.044	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.6

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: rs1318640024; hg19: chr11-68671435;