11-2135446-G-C

Variant names:

• chr11-2135446-G-C
• rs1064794050
• NM_000612.6:c.78C>G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_000612.6(IGF2):​c.78C>G​(p.Tyr26*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 34)
• Consequence: IGF2 NM_000612.6 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 1.92

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_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 8 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-2135446-G-C is Pathogenic according to our data. Variant chr11-2135446-G-C is described in ClinVar as [Pathogenic]. Clinvar id is 253036.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr11-2135446-G-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
IGF2	NM_000612.6	c.78C>G	p.Tyr26*	stop_gained	Exon 2 of 4	ENST00000416167.7	NP_000603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
IGF2	ENST00000416167.7	c.78C>G	p.Tyr26*	stop_gained	Exon 2 of 4	1	NM_000612.6	ENSP00000414497.2
IGF2	ENST00000381392.5	c.78C>G	p.Tyr26*	stop_gained	Exon 2 of 4	1		ENSP00000370799.1
IGF2	ENST00000381406.8	c.78C>G	p.Tyr26*	stop_gained	Exon 2 of 4	2		ENSP00000370813.4
ENSG00000284779	ENST00000643349	c.*85C>G		3_prime_UTR_variant	Exon 3 of 5			ENSP00000495715.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 34

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Sep 05, 2015

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Y26X nonsense variant in the IGF2 gene has not been reported previously as a pathogenic variantnor as a benign polymorphism, to our knowledge. This variant is predicted to cause loss of normalprotein function either through protein truncation or nonsense-mediated mRNA decay. Y26Xwas not observed in approximately 6500 individuals of European and African Americanancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant inthese populations. We interpret Y26X as a pathogenic variant. -

Silver-Russell syndrome 1 Pathogenic:1

-

Centre de Recherche Saint Antoine, Université Pierre et Marie Curie

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	41
DANN	Uncertain	1.0
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Uncertain	0.87	D
Vest4		0.93
GERP RS		2.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs1064794050; hg19: chr11-2156676;