Gene
GP1BB
glycoprotein Ib platelet subunit beta
- HGNC 4440(opens in a new tab)
- Ensembl gene ENSG00000203618(opens in a new tab)
- NCBI Gene 2812(opens in a new tab)
Summary
- Cytogenetic location
- 22q11.21
- Coordinates
- Chromosome 22: 19,723,539–19,724,771 (GRCh38)
- Exons
- 2 exons across 1.2 kb
- Protein
- 206 amino acids
- Inheritance
- Autosomal recessive
- Also known as
- CD42c, GPIbbeta
- MANE Select transcript
- ENST00000366425.4NM_000407.5
- Locus type
- gene with protein product
- Very high
- Confident
- Low
- Very low
Reference genomeGRCh38hg38
Positions on gene and variant pages follow this choice, in this browser.
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Inherited Platelet Function Disorders
- Bernard-Soulier SyndromeAutosomal recessive
A disorder caused by changes in GP1BA, GP1BB or GP9, in which platelets are large, reduced in number and cannot stick to damaged blood vessels; it is usually recessive, though milder dominant forms exist.
- ClinGen rates the link definitive
- 4 GenCC submitters rate it definitive or strong
What knowing changes
A correct diagnosis avoids it being mistaken for immune thrombocytopenia and treated unnecessarily.
Inherited Thrombocytopenias
- Inherited Thrombocytopenia
A group of conditions causing a lifelong low platelet count, linked to genes such as MYH9, ANKRD26, ETV6, WAS, MPL, RBM8A, GATA1 and MECOM, and inherited in dominant, recessive or X-linked patterns.
- 1 GenCC submitter rates it definitive or strong
What knowing changes
A genetic diagnosis avoids misdiagnosis as immune thrombocytopenia, with unnecessary steroids or spleen removal, and guides monitoring for related kidney, hearing or blood problems.
Inheritance
- Autosomal recessive
- It takes a changed copy from each parent. With one, you are a carrier and usually unaffected; when both parents are carriers, each child has a one-in-four chance of inheriting two.
How GP1BB is laid out
- Coding sequence
- Untranslated region
- Intron
- Direction of transcription
- Known disease-causing sites
- Variants with a page
Exons of the gene's MANE Select transcript (release v1.5), from NCBI and EMBL-EBI, on the GRCh38 reference genome.
Chromosome bands from UCSC's GRCh38 ideogram (2022-10-29).
Nearby genes from Ensembl release 116, on GRCh38.
Exons make up 1 kb of the gene's 1.2 kb; 621 of those bases code for the protein.
How a genome test reads GP1BB
33
positions in GP1BB where ClinVar classes a change as pathogenic or likely pathogenic
None of them falls in a region short reads find hard.
A whole genome covers all 1.2 kb of GP1BB, introns included, not only the 1 kb of exons.
Variants with a page (21)
The GP1BB variants with a page here, most review stars first. Each page describes ClinVar's public record of the variant, never a result.
| Variant | HGVS c. | Exon or intron | Position (GRCh38) | ClinVar classification | Review status |
|---|---|---|---|---|---|
| A105Pfs*88 | c.313del | Exon 2 | 19,724,154 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel |
| A150Rfs*43 | c.448del | Exon 2 | 19,724,285 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel |
| A156Gfs*153 | c.466dup | Exon 2 | 19,724,308 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel |
| c.1A>T | Exon 1 | 19,723,570 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel | |
| C30Y | c.89G>A | Exon 2 | 19,723,932 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel |
| C32X | c.96C>A | Exon 2 | 19,723,939 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel |
| C141X | c.423C>A | Exon 2 | 19,724,266 | Pathogenic | 3 stars out of 4 reviewed by expert panel |
| C147S | c.439T>A | Exon 2 | 19,724,282 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel |
| E136X | c.406G>T | Exon 2 | 19,724,249 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel |
| G106Afs*87 | c.315del | Exon 2 | 19,724,156 | Pathogenic | 3 stars out of 4 reviewed by expert panel |
Traits linked to GP1BB
The Human Phenotype Ontology lists these as features of the rare conditions GP1BB can cause. Each trait's page lists the other genes linked to it.
Abnormality of blood and blood-forming tissues
- Impaired ristocetin-induced platelet aggregation
- Low platelet count
- Macrothrombocytopenia
- Neonatal alloimmune thrombocytopenia
- Bleeding tendency
- Decreased platelet glycoprotein Ib-IX-V
- Giant platelets
- Large platelets
Show 21 more traits
- Abnormally heavy bleeding during menstruation
- Blood spots
- Cephalohematoma
- Gastrointestinal bleeding
- Petechiae
- Platelet anisocytosis
- Prolonged bleeding after dental extraction
- Recurring nosebleed
- Spontaneous hematomas
- Abnormal megakaryocyte morphology
- Black feces
- Bleeding gums
- Bleeding within the skull
- Bloody nose
- Bruising susceptibility
- Ecchymosis
- Platelet abnormalities
- Prolonged bleeding after surgery
- Vomiting blood
- Subarachnoid hemorrhage
- Prolonged bleeding time
Abnormality of head or neck
- Abnormal facial shape
- Bulbous nose
- Cleft palate
- Corners of eye widely separated
- Eye folds
- Flattening of the skull base
- Prominent nasal bridge
- Upward slanting of the opening between the eyelids
Show 19 more traits
- Wide nasal bridge
- Abnormal dentition
- Abnormality of the eyelid
- Abnormality of the skull
- Dental cavities
- Long face
- Long philtrum
- Short neck
- Zygomatic flattening
- Abnormal tooth enamel
- Abnormally small head
- Blockage of the rear opening of the nasal cavity
- Downward slanting of the opening between the eyelids
- Little lower jaw
- Multiple suture craniosynostosis
- Narrow mouth
- Retinal arteriolar tortuosity
- Short philtrum
- Tall shaped head
Abnormality of the eye
- Drooping upper eyelid
- New blood vessel formation in cornea
- Posterior embryotoxon
- Abnormally small eyeball
- Clouding of the lens of the eye
- Cross-eyed
- Glaucoma
- Optic atrophy
Show 2 more traits
External links
Gene records
Transcript
Protein
Where this comes from
- HGNC: the gene's symbol, name, other symbols and location.
- MANE Select v1.5, from NCBI and EMBL-EBI: the transcript, its exons and coding sequence.
- GenCC and ClinGen, released 2026-10-16: which conditions the gene is linked to, and how strongly.
- The ACMG secondary findings list, SF v3.2.
- ClinVar and the GIAB stratifications: known disease-causing sites, and the regions short reads find hard.
- The Human Phenotype Ontology, release 2026-09-01: the traits linked to the gene. Find out more at hpo.jax.org.
- Data release 2026.10.16-c6eea6bf.
Cite this page
Dante Labs. (n.d.). GP1BB gene: glycoprotein Ib platelet subunit beta. Retrieved 16 October 2026, from https://dantelabs.com/genes/gp1bb
Dante Labs. GP1BB gene: glycoprotein Ib platelet subunit beta [Internet]. [cited 16 October 2026]. Available from: https://dantelabs.com/genes/gp1bb
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