# NM_004336.5(BUB1):c.216T>C (p.Cys72=)

https://sugi.bio/variant/bub1-p-cys72

## Summary

**BUB1 p.Cys72= (c.216T>C)** is classified **Likely benign** in BUB1 (ClinVar, Single submitter, 1 submitter; last evaluated 2022-04-22). Very rare (popmax 0.00176%, amr).

**At a glance:** Likely benign · review: Single submitter · rsID rs369663570 · 1 submitter · very rare (popmax 0.00176%, amr)

## For patients & families {#patients}

This is a change in the BUB1 gene that is classified as likely benign — not considered disease-causing, submitted by 1 submitter.

*Reference information, not medical advice, and not a prediction for any individual. A genetic counselor or clinician can interpret what it means for you and your family.*

**Support & next steps:** [Find a genetic counselor (NSGC)](https://findageneticcounselor.nsgc.org/).

## Identity {#identity}

| Field | Value |
| --- | --- |
| Gene | [BUB1](https://sugi.bio/atlas/gene/BUB1/) |
| Protein change (HGVS p.) | p.Cys72= |
| Coding change (HGVS c.) | c.216T>C |
| MANE Select transcript | [NM_004336](https://www.ncbi.nlm.nih.gov/nuccore/NM_004336) |
| dbSNP | [rs369663570](https://www.ncbi.nlm.nih.gov/snp/rs369663570/) |
| Variant type | single nucleotide variant |
| Location | chr2:110674095-110674095 (GRCh38) |
| ClinVar | [VCV1787074](https://www.ncbi.nlm.nih.gov/clinvar/variation/1787074/) |

**All HGVS expressions:** `NC_000002.11:g.111431672A>G`, `NC_000002.12:g.110674095A>G`, `NG_012048.1:g.9013T>C`, `NG_012048.2:g.8968T>C`, `NM_001278616.2:c.156T>C`, `NM_001278617.2:c.216T>C`, `NM_004336.5:c.216T>C`

## Computational & population evidence {#evidence}

**Concordance:** Mixed / partial computational evidence (see below).

- **Missense predictors (AlphaMissense/REVEL/SaProt) do not apply** to this variant type — they score amino-acid substitutions only. For non-missense variants the computational signal comes from conservation (below), not from a missing predictor score.
- Conservation: phyloP 2.448, phastCons 1 — highly conserved position (PP3-type support)
- CADD: **PHRED 8.569**. No single ClinGen-calibrated threshold exists and the expert panels that use CADD disagree — GUCY2D/AIPL1 require ≥ 20.0 for an untranslated-region variant, ABCA4 ≥ 28.1 for a synonymous or indel variant, the Pulmonary Hypertension panel imports Pejaver 2022's missense-calibrated numbers, and the Antibody Deficiencies panel declines CADD entirely for PIK3CD. CADD v1.7 also incorporates Zoonomia phyloP, so it partly re-expresses the conservation above. *Descriptive; no threshold applied.*
- SpliceAI: **no splice effect predicted**. SpliceAI outputs four numbers per variant, not one: acceptor loss, donor loss, acceptor gain, donor gain (DS_AL / DS_DL / DS_AG / DS_DG). A loss score is an existing splice site weakened or destroyed; a gain score is a new site created or an existing one strengthened. The release publishes its own filter rule, which we read from the dataset rather than assume: an allele is reported only if the largest of its four deltas reaches 0.2. No allele at this position is in the release, so all four are under 0.2 for every alternate allele here. No figure is shown because none was read: the bound is deduced from that absence. It is a result, not a gap in our data, because the release scores every possible substitution across the transcripts it covers (Ensembl MANE v1.4) before it filters, so what survives for a gene is one continuous stretch. What is measured is that this position sits inside the stretch covered for BUB1 (1,173 scored positions, the nearest 6 bases away); what is taken from the release's own description, rather than measured, is that coverage inside that stretch is continuous. On that, SpliceAI did score it. *ClinGen's SVI treats the largest of the four as evidence against a splicing effect at or below 0.1, where it may support BP4, and as uninformative between 0.1 and 0.2. We cannot tell which applies here, so these SpliceAI data support neither BP4 nor PP3; that is a statement about this evidence alone, not about the variant's other evidence.*
- Population frequency (gnomAD v4.1): grpmax **0.00176%** (amr) · FAF95 0.000195% · FAF99 0.000128% · 1/56,734 in the highest group · 10/1,524,458 alleles overall — very rare (popmax 0.00176%, amr).

| Ancestry group | Allele frequency | 1 in |
| --- | --- | --- |
| Remaining individuals (not grpmax-eligible) | 0.00337% | 29,709 |
| Admixed American (grpmax) | 0.00176% | 56,734 |
| African / African-American | 0.00138% | 72,266 |
| European (non-Finnish) | 0.000542% | 184,454 |

Remaining individuals shows a higher raw frequency than the grpmax group. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and "Remaining individuals" — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

*Computational predictors are not independent (ClinGen Variant Classification guidance): AlphaMissense (Cheng et al. 2023) carries the ACMG weight for missense and conservation (phyloP/GERP/phastCons) for non-missense; REVEL (Pejaver-2022 calibrated strength bands) and SaProt (Su et al. 2023, structure-aware, ClinVar-independent protein language model, raw LLR) are shown as orthogonal agreement signals, not additive. For frequency, the gnomAD v4.1 grpmax filtering allele frequency (FAF95) is ClinGen's designated BA1/BS1 input (gnomAD v4 guidance v3.0, June 2025); BA1/BS1 thresholds are disease-specific, not a blanket 5%. Predictions, not a clinical determination.*

## Gene constraint & dosage {#gene-context}

**BUB1** population constraint: LOEUF 0.727, pLI 7.3293e-13, missense-Z 1.4894. *Lower LOEUF and higher pLI indicate a gene that tolerates loss-of-function poorly; ClinGen dosage is the curated haploinsufficiency call.*

Curated gene–disease validity (ClinGen):

- **colorectal cancer** — Limited (AD)

## Protein context {#protein}

Residue **72** lies in the bub1 n-terminal domain; the 'necessary for kinetochore localization' region; an α-helix.

AlphaFold model confidence (whole protein): pLDDT 63.91, 31% of residues very-high.

**11 experimental structure(s)** (PDB): [2LAH](https://www.rcsb.org/structure/2LAH), [4A1G](https://www.rcsb.org/structure/4A1G), [4QPM](https://www.rcsb.org/structure/4QPM), [4R8Q](https://www.rcsb.org/structure/4R8Q), [5DMZ](https://www.rcsb.org/structure/5DMZ), [6F7B](https://www.rcsb.org/structure/6F7B).

## What this gene does {#gene-function}

*Describes the biological roles of BUB1 (the gene this variant disrupts) — not effects measured for this specific variant. A damaging variant is expected to affect these functions and pathways; the degree depends on the variant.*

**How this variant is thought to act:** BUB1's established molecular role includes protein kinase activity. p.Cys72= falls in the bub1 n-terminal domain.


### Pathways affected {#pathways}

BUB1 participates in **6 Reactome pathways** (⚕ = disease pathway):

| Pathway (Reactome) | Evidence |
| --- | --- |
| [Amplification  of signal from unattached  kinetochores via a MAD2  inhibitory signal](https://reactome.org/content/detail/R-HSA-141444) | curated |
| [EML4 and NUDC in mitotic spindle formation](https://reactome.org/content/detail/R-HSA-9648025) | curated |
| [Mitotic Prometaphase](https://reactome.org/content/detail/R-HSA-68877) | curated |
| [RHO GTPases Activate Formins](https://reactome.org/content/detail/R-HSA-5663220) | curated |
| [Resolution of Sister Chromatid Cohesion](https://reactome.org/content/detail/R-HSA-2500257) | curated |
| [Separation of Sister Chromatids](https://reactome.org/content/detail/R-HSA-2467813) | curated |

### Molecular function & processes (GO — experimentally supported) {#go}

**Molecular function:** protein kinase activity, protein serine/threonine kinase activity, histone H2A kinase activity.

**Biological process:** regulation of sister chromatid cohesion, mitotic spindle assembly checkpoint signaling, regulation of chromosome segregation, positive regulation of maintenance of mitotic sister chromatid cohesion, centromeric.

## Clinical significance {#significance}

**Likely benign** — review status Single submitter *(criteria provided, single submitter)*, last evaluated 2022-04-22.

**Submitter consensus:** unanimous (1/1 Likely benign).

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| Ambry Genetics | Likely benign | criteria provided, single submitter | clinical testing | 2022-04-22 |

**Reported phenotype names (ClinVar):** not specified, AllHighlyPenetrant.

## Similar variants {#similar}

Related BUB1 variant pages (same residue, condition, or type): [BUB1 p.Cys72Ser](/variant/bub1-p-cys72ser), [BUB1 p.Cys72Tyr](/variant/bub1-p-cys72tyr), [BUB1 c.1698+1G>T](/variant/bub1-c-1698-plus-1g-t), [BUB1 p.Ala281Thr](/variant/bub1-p-ala281thr), [BUB1 p.Ala283Thr](/variant/bub1-p-ala283thr), [BUB1 p.Ala499Val](/variant/bub1-p-ala499val), [BUB1 p.Ala502Ser](/variant/bub1-p-ala502ser), [BUB1 p.Ala630Gly](/variant/bub1-p-ala630gly).

### Data sources & attribution {#sources}

ClinVar (NCBI — public domain, built 2026-10-14); gnomAD v4.1 (Broad Institute, built 2026-10-15); AlphaMissense (Cheng et al. 2023, © Google DeepMind — CC BY 4.0, built 2026-01-27); REVEL (Ioannidis et al. 2016 — ODbL, built 2026-07-13); SaProt (Su et al. 2023 — MIT, built 2026-10-14); SpliceAI (Illumina — free for non-commercial use, built 2026-10-13); CADD (Rentzsch et al. 2019, University of Washington — free for non-commercial use, built 2026-10-10); Conservation (phyloP/phastCons/GERP) (UCSC hg38 470-way mammal (Hiller Lab) + Ensembl Compara, built 2026-07-12); gnomAD Non-coding Constraint (Gnocchi) (Chen et al. 2024, Broad Institute — CC0, built 2026-10-11); gnomAD Regional Missense Constraint (Broad Institute — CC0, built 2026-10-13); Pangolin (Zeng & Li 2022 — CC BY 4.0, built 2026-10-11); Repeat regions (UCSC — RepeatMasker, TRF, segmental duplications, built 2026-10-11); ClinGen (ClinGen, built 2026-09-22); UniProt (CC BY 4.0); Reactome / GO (CC BY 4.0, built 2026-09-23); MaveDB (per-record license, built 2026-10-11); CIViC (CC0, built 2026-09-22); Orphanet (Orphanet, built 2026-06-12)

*Primary record: NCBI ClinVar (variation 1787074). Classifications reflect these databases as of the page's build date and may change. Free reference use — not medical advice; consult the primary submitters and a clinician.*