11-2133011-TG-T

Position:

• chr11-2133011-TG-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PVS1_Moderate BS2

The NM_000612.6(IGF2):​c.518delC​(p.Pro173fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000115 in 1,394,088 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000011 (0 hom.)
• Consequence: IGF2 NM_000612.6 frameshift
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.11

Genes affected

IGF2 (HGNC:5466): (insulin like growth factor 2) This gene encodes a member of the insulin family of polypeptide growth factors, which are involved in development and growth. It is an imprinted gene, expressed only from the paternal allele, and epigenetic changes at this locus are associated with Wilms tumour, Beckwith-Wiedemann syndrome, rhabdomyosarcoma, and Silver-Russell syndrome. A read-through INS-IGF2 gene exists, whose 5' region overlaps the INS gene and the 3' region overlaps this gene. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2010]

ENSG00000284779 (HGNC:):

INS-IGF2 (HGNC:33527): (INS-IGF2 readthrough) This locus includes two alternatively spliced read-through transcript variants which align to the INS gene in the 5' region and to the IGF2 gene in the 3' region. One transcript is predicted to encode a protein which shares the N-terminus with the INS protein but has a distinct and longer C-terminus, whereas the other transcript is a candidate for nonsense-mediated decay (NMD). The transcripts are imprinted and are paternally expressed in the limb and eye. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.046 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• BS2: High AC in GnomAdExome4 at 16 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
IGF2	NM_000612.6	c.518delC	p.Pro173fs	frameshift_variant	4/4	ENST00000416167.7	NP_000603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
IGF2	ENST00000416167.7	c.518delC	p.Pro173fs	frameshift_variant	4/4	1	NM_000612.6	ENSP00000414497.2
IGF2	ENST00000381392.5	c.527delC	p.Pro176fs	frameshift_variant	4/4	1		ENSP00000370799.1
IGF2	ENST00000381406.8	c.527delC	p.Pro176fs	frameshift_variant	4/4	2		ENSP00000370813.4
ENSG00000284779	ENST00000643349.2	c.*570delC		3_prime_UTR_variant	5/5			ENSP00000495715.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.0000115 AC: 16 AN: 1394088 Hom.: 0 Cov.: 31 AF XY: 0.0000160 AC XY: 11 AN XY: 687108

Gnomad4 AFR exome AF: 0.0000324

Gnomad4 AMR exome AF: 0.0000882

Gnomad4 ASJ exome AF: 0.0000440

Gnomad4 EAS exome AF: 0.0000267

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000927

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 12, 2024

Frameshift variant predicted to result in abnormal protein length as the last 8 amino acids are replaced with 26 different amino acids; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

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: rs755455183; hg19: chr11-2154241;