chr5-68293835-G-C

Position:

• chr5-68293835-G-C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_181523.3(PIK3R1):​c.1425+1G>C variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PIK3R1 NM_181523.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 9.35

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]

PIK3R1 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.057471264 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-68293835-G-C is Pathogenic according to our data. Variant chr5-68293835-G-C is described in ClinVar as [Pathogenic]. Clinvar id is 156009.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PIK3R1	NM_181523.3	c.1425+1G>C		splice_donor_variant, intron_variant		ENST00000521381.6	NP_852664.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PIK3R1	ENST00000521381.6	c.1425+1G>C		splice_donor_variant, intron_variant		1	NM_181523.3	ENSP00000428056.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Jan 26, 2017

- -

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 13, 2022

The c.1425+1G>C intronic variant results from a G to C substitution one nucleotide after exon 11 (coding exon 10) of the PIK3R1 gene. Alterations that disrupt the canonical splice site are expected to result in aberrant splicing. The resulting transcript is predicted to be in-frame and is not expected to trigger nonsense-mediated mRNA decay. This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This alteration has been reported in multiple individuals with PIK3R1-related immunodeficiency (Deau, 2014; Lucas, 2014; Elkaim, 2016; Kuhlen, 2015). Another alteration impacting the same donor site (c.1425+1G>A) has been shown to have a similar impact on splicing (skipping of coding exon 10) in an individual with hyper IgM syndrome, lymphadenopathy, and short stature (Petrovski, 2016). This nucleotide position is highly conserved in available vertebrate species. RT-PCR sequencing showed that this alteration resulted in an in-frame deletion of coding exon 10 (Deau, 2014). Functional analysis demonstrated that the alteration abrogates inhibitory activity and promotes AKT activation resulting in a mutant p85αΔ434_475 that was observed to be less stable than the wild type protein (Deau, 2014). In silico splice site analysis predicts that this alteration will weaken the native splice donor site. Based on the available evidence, this alteration is classified as pathogenic. -

See cases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Center for Personalized Medicine, Children's Hospital Los Angeles

Dec 21, 2022

- -

SHORT syndrome;C3554689:Agammaglobulinemia 7, autosomal recessive;C4014934:Immunodeficiency 36 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 26, 2022

For these reasons, this variant has been classified as Pathogenic. Studies have shown that disruption of this splice site results in skipping of exon 11, but is expected to preserve the integrity of the reading-frame (PMID: 25133428, 25488983). ClinVar contains an entry for this variant (Variation ID: 156009). This variant is also known as g.67589663G>C. Disruption of this splice site has been observed in individual(s) with activated PI3K delta syndrome (APDS2) (PMID: 25133428, 25488983, 26529633). In at least one individual the variant was observed to be de novo. This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 11 of the PIK3R1 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product. -

Immunodeficiency 36 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Mar 01, 1995

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	1.0	D
GERP RS		5.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		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: rs587777709; hg19: chr5-67589663; COSMIC: COSV57140308; COSMIC: COSV57140308;