chr5-68295418-AGGT-A

Position:

• chr5-68295418-AGGT-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PVS1_Moderate PM2 PP3_Moderate PP5

The NM_181523.3(PIK3R1):​c.1748_1750del​(p.Trp583del) variant causes a splice acceptor, coding sequence change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PIK3R1 NM_181523.3 splice_acceptor, coding_sequence
• Clinical Significance: Pathogenic/Likely pathogenic no assertion criteria provided P:2
• Conservation: PhyloP100: 10.0

Genes affected

PIK3R1 (HGNC:8979): (phosphoinositide-3-kinase regulatory subunit 1) Phosphatidylinositol 3-kinase phosphorylates the inositol ring of phosphatidylinositol at the 3-prime position. The enzyme comprises a 110 kD catalytic subunit and a regulatory subunit of either 85, 55, or 50 kD. This gene encodes the 85 kD regulatory subunit. Phosphatidylinositol 3-kinase plays an important role in the metabolic actions of insulin, and a mutation in this gene has been associated with insulin resistance. Alternative splicing of this gene results in four transcript variants encoding different isoforms. [provided by RefSeq, Jun 2011]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.03126437 fraction of the gene. Cryptic splice site detected, with MaxEntScore 9, offset of 0 (no position change), new splice context is: ttttcaaaactgtttttcAGgtt. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 5-68295418-AGGT-A is Pathogenic according to our data. Variant chr5-68295418-AGGT-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 376263.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr5-68295418-AGGT-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PIK3R1	NM_181523.3	c.1748_1750del	p.Trp583del	splice_acceptor_variant, coding_sequence_variant	14/16	ENST00000521381.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PIK3R1	ENST00000521381.6	c.1748_1750del	p.Trp583del	splice_acceptor_variant, coding_sequence_variant	14/16	1	NM_181523.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: no assertion criteria provided

Submissions by phenotype

Neoplasm Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Database of Curated Mutations (DoCM)

Jul 14, 2015

- -

Vascular Malformations and Overgrowth Pathogenic:1

Pathogenic, no assertion criteria provided

research

Institute for Genomic Medicine (IGM) Clinical Laboratory, Nationwide Children's Hospital

Nov 08, 2020

This alteration is of apparent somatic mosaic etiology with strong supporting evidence including no discernible strand bias, in a region absent of repetition and sequence homology, with clean, high-quality reads, having a variant allele fraction >= 3% [PS2], is supported by well-established models demonstrating downstream impact of the variant on RNA structure, gene expression, or protein function [PS3], is either well-represented in cancer as identified in the COSMIC database with >=20 documented instances or considered to occur in a statistically significant hotspot or region according to cancerhotspots.org database [PM_CANCER], is in a non-repetitive region and results in a protein length change predicted to result in an in-frame protein product [PM4], and is at increased prevalence in our cohort, with >= 3 occurrences in unrelated individuals [PS4_Sup]. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		1.0		Position offset: 5
DS_AL_spliceai		1.0		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1131692243; hg19: chr5-67591246;