GENE REFERENCE / HGNC:8979

PIK3R1

phosphoinositide-3-kinase regulatory subunit 1

protein-coding gene5q13.1Gene information

What does this gene do?

The PIK3R1 gene provides instructions for making a part (subunit) of an enzyme called phosphatidylinositol 3-kinase (PI3K). The primary function of the subunit is to regulate the enzyme's activity. Several slightly different versions of this regulatory subunit are produced from the PIK3R1 gene; the most abundant of these is called p85 alpha (p85α).

PI3K is a kinase, which means that it adds a cluster of oxygen and phosphorus atoms (a phosphate group) to other proteins through a process called phosphorylation. PI3K phosphorylates certain signaling molecules, which triggers a series of additional reactions that transmit chemical signals within cells. PI3K signaling is important for many cell activities, including cell growth and division (proliferation), movement (migration) of cells, production of new proteins, transport of materials within cells, and cell survival.

Studies suggest that PI3K signaling may be involved in how cells regulate several hormones. One of these hormones is insulin, which helps control levels of blood glucose, also called blood sugar. PI3K signaling may also play a role in the maturation of fat cells (adipocytes).

Source: MedlinePlus, National Library of Medicine. Source publication: 2023-08-16. Source review: 2023-08.

ClinGen reviews

ClinGen reviews the evidence linking a particular gene to a condition. Each rating below describes the strength of that link. It does not classify a variant in your DNA file.

Condition	Inheritance	Evidence
PIK3R1-related immunodeficiency and SHORT syndromeMONDO:1060136 · Evaluated 2025-03-11	Autosomal dominant	DefinitiveAntibody Deficiencies Gene Curation Expert Panel
agammaglobulinemia 7, autosomal recessiveMONDO:0014083 · Evaluated 2021-05-20	Autosomal recessive	LimitedAntibody Deficiencies Gene Curation Expert Panel

ClinVar records

These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.

Submitted alleles: 797
Submissions for variants in or overlapping this gene: 1,232
Submissions explicitly reporting this gene: 1,199
Alleles reported pathogenic / likely pathogenic: 87
VariationIDs with uncertain significance: 328
VariationIDs with conflicting classifications: 12

The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.

NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about PIK3R1?

From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 87 alleles in PIK3R1 reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.

From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.

If a variant is not in your file, that does not mean you don’t have it.

What BioDecode checks

BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.

A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in PIK3R1.

BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.

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