chr15-98649674-AAGTG-A

Position:

• chr15-98649674-AAGTG-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Strong PP3_Moderate

The NM_000875.5(IGF1R):​c.94+3_94+6del variant causes a splice donor, splice donor region, coding sequence, intron change. The variant allele was found at a frequency of 0.0000162 in 1,607,578 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000017 (0 hom.)
• Consequence: IGF1R NM_000875.5 splice_donor, splice_donor_region, coding_sequence, intron
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.72

Genes affected

IGF1R (HGNC:5465): (insulin like growth factor 1 receptor) This receptor binds insulin-like growth factor with a high affinity. It has tyrosine kinase activity. The insulin-like growth factor I receptor plays a critical role in transformation events. Cleavage of the precursor generates alpha and beta subunits. It is highly overexpressed in most malignant tissues where it functions as an anti-apoptotic agent by enhancing cell survival. Alternatively spliced transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq, May 2014]

IRAIN (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.2768031 fraction of the gene. Cryptic splice site detected, with MaxEntScore 6.9, offset of 0 (no position change), new splice context is: aaaGTatgt. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
IGF1R	NM_000875.5	c.94+3_94+6del		splice_donor_variant, splice_donor_region_variant, coding_sequence_variant, intron_variant	1/21	ENST00000650285.1
IRAIN	NR_126453.2	n.1110_1113del		non_coding_transcript_exon_variant	1/1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
IGF1R	ENST00000650285.1	c.94+3_94+6del		splice_donor_variant, splice_donor_region_variant, coding_sequence_variant, intron_variant	1/21		NM_000875.5	P4
IGF1R	ENST00000559925.5	n.94+3_94+6del		splice_donor_variant, splice_donor_region_variant, non_coding_transcript_exon_variant, intron_variant	1/10	1
IGF1R	ENST00000649865.1	c.94+3_94+6del		splice_donor_variant, splice_donor_region_variant, coding_sequence_variant, intron_variant	1/21			A1

Frequencies

GnomAD3 genomes AF: 0.00000659 AC: 1 AN: 151818 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.0000951

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000364 AC: 9 AN: 247466 Hom.: 0 AF XY: 0.0000298 AC XY: 4 AN XY: 134388

Gnomad AFR exome AF: 0.0000629

Gnomad AMR exome AF: 0.0000297

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000551

Gnomad SAS exome AF: 0.0000994

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000268

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000172 AC: 25 AN: 1455760 Hom.: 0 AF XY: 0.0000166 AC XY: 12 AN XY: 724478

Gnomad4 AFR exome AF: 0.0000601

Gnomad4 AMR exome AF: 0.000113

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000253

Gnomad4 SAS exome AF: 0.0000233

Gnomad4 FIN exome AF: 0.0000382

Gnomad4 NFE exome AF: 0.00000902

Gnomad4 OTH exome AF: 0.0000498

GnomAD4 genome AF: 0.00000659 AC: 1 AN: 151818 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74144

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.0000951

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000151

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

Labcorp Genetics (formerly Invitae), Labcorp

Nov 15, 2023

This sequence change falls in intron 1 of the IGF1R gene. It does not directly change the encoded amino acid sequence of the IGF1R protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs779160550, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with IGF1R-related conditions. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.96		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.40		Position offset: 5
DS_DL_spliceai		0.96		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs779160550; hg19: chr15-99192903;