# NM_000384.3(APOB):c.9615del (p.Asp3205fs)

https://sugi.bio/variant/apob-p-asp3205fs

## Summary

**APOB p.Asp3205fs (c.9615del)** is classified **Pathogenic** in APOB (ClinVar, Single submitter, 1 submitter; last evaluated 2020-03-22). No gnomAD frequency available for this variant; Associated with familial hypobetalipoproteinemia 1.

**At a glance:** Pathogenic · review: Single submitter · rsID rs2103352794 · 1 submitter · 2 linked conditions · no gnomAD frequency available for this variant

## For patients & families {#patients}

This is a change in the APOB gene that is reported as disease-causing, but on limited review, submitted by 1 submitter, and is linked to familial hypobetalipoproteinemia 1.

*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.*

|  |  |
| --- | --- |
| Clinical trials | 7 registered for this condition — see ClinicalTrials.gov |

**Support & next steps:** [Condition overview & support (NIH GARD)](https://rarediseases.info.nih.gov/diseases/0002876/index) · [Find a genetic counselor (NSGC)](https://findageneticcounselor.nsgc.org/).

## Identity {#identity}

| Field | Value |
| --- | --- |
| Gene | [APOB](https://sugi.bio/atlas/gene/APOB/) |
| Protein change (HGVS p.) | p.Asp3205fs |
| Coding change (HGVS c.) | c.9615del |
| MANE Select transcript | [NM_000384](https://www.ncbi.nlm.nih.gov/nuccore/NM_000384) |
| dbSNP | [rs2103352794](https://www.ncbi.nlm.nih.gov/snp/rs2103352794/) |
| Variant type | Deletion |
| Location | chr2:21007253-21007253 (GRCh38) |
| ClinVar | [VCV1068824](https://www.ncbi.nlm.nih.gov/clinvar/variation/1068824/) |

**All HGVS expressions:** `NC_000002.11:g.21230125del`, `NC_000002.12:g.21007253del`, `NG_011793.1:g.41821del`, `NM_000384.3:c.9615del`

## 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 0.271, GERP -3.06 — weakly conserved position
- Molecular consequence: **frameshift** — a predicted loss-of-function variant. ClinGen curates **sufficient evidence for haploinsufficiency** in this gene, supporting a loss-of-function disease mechanism. *Descriptive; not an applied PVS1 code.*
- Nonsense-mediated decay: the premature termination codon is **in exon 26 of 29**, so the transcript is predicted to undergo NMD.
- SpliceAI: **not assessed** — the release is built from a substitutions-only source, so it holds no deletion variants. That is a property of the dataset, not of the variant, and is not evidence against a splicing effect.
- Population frequency: **no gnomAD frequency available for this variant** — rarity (ACMG PM2) and BA1/BS1 cannot be assessed for this variant.

*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}

**APOB** population constraint: LOEUF 0.537, pLI 1.3512e-11, missense-Z 0.96416; ClinGen dosage — haploinsufficiency 3, triplosensitivity 0 (0–3 scale). *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):

- **hypercholesterolemia, autosomal dominant, type B** — Definitive (AD)
- **familial hypobetalipoproteinemia 1** — Definitive (SD)

## Protein context {#protein}

Residue **3205** lies in a disulfide bond; the 'heparin-binding' region.

**8 experimental structure(s)** (PDB): [9BD1](https://www.rcsb.org/structure/9BD1), [9BD8](https://www.rcsb.org/structure/9BD8), [9BDE](https://www.rcsb.org/structure/9BDE), [9BDT](https://www.rcsb.org/structure/9BDT), [9COO](https://www.rcsb.org/structure/9COO), [9E9R](https://www.rcsb.org/structure/9E9R).

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

*Describes the biological roles of APOB (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:** APOB's established molecular role includes phospholipid binding. p.Asp3205fs falls in the heparin-binding region.


### Pathways affected {#pathways}

APOB participates in **20 Reactome pathways** (⚕ = disease pathway):

| Pathway (Reactome) | Evidence |
| --- | --- |
| [Cargo recognition for clathrin-mediated endocytosis](https://reactome.org/content/detail/R-HSA-8856825) | curated |
| [Cell surface interactions at the vascular wall](https://reactome.org/content/detail/R-HSA-202733) | curated |
| [Chylomicron assembly](https://reactome.org/content/detail/R-HSA-8963888) | curated |
| [Chylomicron remodeling](https://reactome.org/content/detail/R-HSA-8963901) | curated |
| [Clathrin-mediated endocytosis](https://reactome.org/content/detail/R-HSA-8856828) | curated |
| [Heme signaling](https://reactome.org/content/detail/R-HSA-9707616) | curated |
| [LDL remodeling](https://reactome.org/content/detail/R-HSA-8964041) | curated |
| [Platelet sensitization by LDL](https://reactome.org/content/detail/R-HSA-432142) | curated |
| [Post-translational protein phosphorylation](https://reactome.org/content/detail/R-HSA-8957275) | curated |
| [Regulation of Insulin-like Growth Factor (IGF) transport and uptake by Insulin-like Growth Factor Binding Proteins (IGFBPs)](https://reactome.org/content/detail/R-HSA-381426) | curated |
| [Regulation of TLR by endogenous ligand](https://reactome.org/content/detail/R-HSA-5686938) | curated |
| [Scavenging by Class H Receptors](https://reactome.org/content/detail/R-HSA-3000497) | curated |
| [VLDL assembly](https://reactome.org/content/detail/R-HSA-8866423) | curated |
| [Chylomicron clearance](https://reactome.org/content/detail/R-HSA-8964026) | electronic |
| [LDL clearance](https://reactome.org/content/detail/R-HSA-8964038) | electronic |
| [Retinoid metabolism and transport](https://reactome.org/content/detail/R-HSA-975634) | electronic |
| [Scavenging by Class A Receptors](https://reactome.org/content/detail/R-HSA-3000480) | electronic |
| [Scavenging by Class B Receptors](https://reactome.org/content/detail/R-HSA-3000471) | electronic |
| [Scavenging by Class F Receptors](https://reactome.org/content/detail/R-HSA-3000484) | electronic |
| [VLDL clearance](https://reactome.org/content/detail/R-HSA-8964046) | electronic |

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

**Molecular function:** phospholipid binding, heparin binding, lipase binding, receptor ligand activity, low-density lipoprotein particle receptor binding, cholesterol transfer activity.

**Biological process:** cholesterol metabolic process, response to virus, positive regulation of macrophage derived foam cell differentiation, positive regulation of lipid storage, positive regulation of cholesterol storage, cholesterol transport.

## Clinical significance {#significance}

**Pathogenic** — review status Single submitter *(criteria provided, single submitter)*, last evaluated 2020-03-22.

**Submitter consensus:** unanimous (1/1 Pathogenic).

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| Labcorp Genetics (formerly Invitae), Labcorp | Pathogenic | criteria provided, single submitter | clinical testing | 2020-03-22 |

## Associated conditions {#conditions}

[familial hypobetalipoproteinemia 1](https://sugi.bio/atlas/disease/familial-hypobetalipoproteinemia-1/), [hypercholesterolemia, autosomal dominant, type B](https://sugi.bio/atlas/disease/hypercholesterolemia-autosomal-dominant-type-b/).

**Reported phenotype names (ClinVar):** Familial hypobetalipoproteinemia 1, Hypercholesterolemia, autosomal dominant, type B, Hypobetalipoproteinemia, normotriglyceridemic, Acanthocytosis with hypobetalipoproteinemia, APOB-Related Familial Hypobetalipoproteinemia, Familial hypercholesterolemia 2, APOB-Related Familial Hypercholesterolemia, Autosomal Dominant, Familial Hypercholesterolemia Type B, APOLIPOPROTEIN B-100, FAMILIAL DEFECTIVE, APOLIPOPROTEIN B-100, FAMILIAL LIGAND-DEFECTIVE.

## Similar variants {#similar}

Related APOB variant pages (same residue, condition, or type): [APOB c.226_237+1del](/variant/apob-c-226-237-plus-1del), [APOB c.78_82+5del](/variant/apob-c-78-82-plus-5del), [APOB p.Asn1755fs](/variant/apob-p-asn1755fs), [APOB p.Asn1772fs](/variant/apob-p-asn1772fs), [APOB p.Gly3617fs](/variant/apob-p-gly3617fs), [APOB p.His2227fs](/variant/apob-p-his2227fs), [APOB p.Leu1345fs](/variant/apob-p-leu1345fs), [APOB p.Leu2914fs](/variant/apob-p-leu2914fs).

### Data sources & attribution {#sources}

ClinVar (NCBI — public domain, built 2026-10-11); gnomAD v4.1 (Broad Institute, built 2026-10-06); 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 2026-07-14); 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 1068824). 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.*