rs1553168726

Variant names:

• chr1-9715634-CAG-C
• rs1553168726
• NM_005026.5:c.236_237delAG

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_005026.5(PIK3CD):​c.236_237delAG​(p.Gln79ProfsTer12) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. Q79Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: PIK3CD NM_005026.5 frameshift
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.66
• Publications: 0 publications found

Genes affected

PIK3CD (HGNC:8977): (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit delta) Phosphoinositide 3-kinases (PI3Ks) phosphorylate inositol lipids and are involved in the immune response. The protein encoded by this gene is a class I PI3K found primarily in leukocytes. Like other class I PI3Ks (p110-alpha p110-beta, and p110-gamma), the encoded protein binds p85 adapter proteins and GTP-bound RAS. However, unlike the other class I PI3Ks, this protein phosphorylates itself, not p85 protein.[provided by RefSeq, Jul 2010]

PIK3CD Gene-Disease associations (from GenCC):

• immunodeficiency 14

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
• immunodeficiency 14b, autosomal recessive

  Inheritance: AR, Unknown Classification: DEFINITIVE, MODERATE, LIMITED Submitted by: ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• activated PI3K-delta syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PIK3CD	NM_005026.5	c.236_237delAG	p.Gln79ProfsTer12	frameshift_variant	Exon 4 of 24	ENST00000377346.9	NP_005017.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PIK3CD	ENST00000377346.9	c.236_237delAG	p.Gln79ProfsTer12	frameshift_variant	Exon 4 of 24	1	NM_005026.5	ENSP00000366563.4

Frequencies

GnomAD3 genomes Cov.: 33

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

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Immunodeficiency 14 Uncertain:1

Nov 01, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Gln79Profs*12) in the PIK3CD gene. It is expected to result in an absent or disrupted protein product. However, the current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in PIK3CD cause disease. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with PIK3CD-related conditions. ClinVar contains an entry for this variant (Variation ID: 541084). 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

Name	Calibrated prediction	Score	Prediction
PhyloP100		4.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1553168726; hg19: chr1-9775692;