# NM_030943.4(AMN):c.512G>C (p.Arg171Pro)

https://sugi.bio/variant/amn-p-arg171pro

## Summary

**AMN p.Arg171Pro (c.512G>C)** is classified **Uncertain significance** in AMN (ClinVar, Single submitter, 1 submitter; last evaluated 2024-05-20). AlphaMissense: ambiguous (0.452); Very rare (popmax 8.48e-05%, nfe); Associated with Inborn genetic diseases.

**At a glance:** Uncertain significance · review: Single submitter · 1 submitter · 1 linked condition · AlphaMissense ambiguous · very rare (popmax 8.48e-05%, nfe)

## For patients & families {#patients}

This is a change in the AMN gene that is currently of uncertain significance — a definitive interpretation has not yet been established, submitted by 1 submitter, and is linked to Inborn genetic diseases.

*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 | [AMN](https://sugi.bio/atlas/gene/AMN/) |
| Protein change (HGVS p.) | p.Arg171Pro |
| Coding change (HGVS c.) | c.512G>C |
| MANE Select transcript | [NM_030943](https://www.ncbi.nlm.nih.gov/nuccore/NM_030943) |
| Variant type | single nucleotide variant |
| Location | chr14:102928974-102928974 (GRCh38) |
| ClinVar | [VCV3293053](https://www.ncbi.nlm.nih.gov/clinvar/variation/3293053/) |

**All HGVS expressions:** `LRG_642:g.11319G>C`, `LRG_642t1:c.512G>C`, `NC_000014.8:g.103395311G>C`, `NC_000014.9:g.102928974G>C`, `NG_008276.2:g.11319G>C`, `NM_030943.4:c.512G>C`

## Computational & population evidence {#evidence}

**Concordance:** AlphaMissense makes no call; SaProt calls this damaging; REVEL does not; AlphaMissense makes no call — descriptive only.

- AlphaMissense **ambiguous** (0.452) — no call either way
- REVEL 0.221 (benign-leaning)
- SaProt LLR -13.941 (damaging)
- → **In-silico consensus:** SaProt calls this damaging; REVEL does not; AlphaMissense makes no call
- Conservation: phyloP 1.664, GERP -2.16, phastCons 0.998 — weakly conserved position
- CADD: **PHRED 20.7**. 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.*
- Regional missense constraint: **o/e 1.06** across the covering region of the MANE Select transcript (102,922,689–102,930,677), spanning 7,988 bp. Chi-square p 0.14. Describes the region, not this allele; gnomAD v4.1.1's own constrained determination. *Descriptive; no ACMG code applied.*
- SpliceAI: **below the reporting threshold**. This position is scored for a different substitution (G>A, Δ0.38 donor loss), so this allele was evaluated and its deltas all fell under Δ0.2 — a prediction of no splicing effect for this allele, not a gap in our data. *No ACMG code assigned.*
- Population frequency (gnomAD v4.1): grpmax **8.48e-05%** (nfe) · 1/1,179,338 in the highest group · 1/1,445,976 alleles overall — very rare (popmax 8.48e-05%, nfe).

*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}

**AMN** population constraint: LOEUF 1.446, pLI 1.8277e-15, missense-Z -2.732; ClinGen dosage — haploinsufficiency 30, 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.*

## Protein context {#protein}

Residue **171** lies in a disulfide bond; a β-strand.

AlphaFold model confidence (whole protein): pLDDT 80.78, 61% of residues very-high.

**1 experimental structure(s)** (PDB): [6GJE](https://www.rcsb.org/structure/6GJE).

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

*Describes the biological roles of AMN (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:** AMN's established molecular role includes signaling receptor binding. In Reactome, AMN is annotated in disease pathway(s) including **Defective AMN causes MGA1**, **Defective CUBN causes MGA1**.

**Disease mechanism (Reactome):** AMN loss or alteration is curated in [Defective AMN causes MGA1](https://reactome.org/content/detail/R-HSA-3359462), [Defective CUBN causes MGA1](https://reactome.org/content/detail/R-HSA-3359463).

### Pathways affected {#pathways}

AMN participates in **4 Reactome pathways** (⚕ = disease pathway):

| Pathway (Reactome) | Evidence |
| --- | --- |
| ⚕ [Defective AMN causes MGA1](https://reactome.org/content/detail/R-HSA-3359462) | other |
| ⚕ [Defective CUBN causes MGA1](https://reactome.org/content/detail/R-HSA-3359463) | other |
| [HDL clearance](https://reactome.org/content/detail/R-HSA-8964011) | other |
| [Uptake of dietary cobalamins into enterocytes](https://reactome.org/content/detail/R-HSA-9758881) | other |

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

**Molecular function:** signaling receptor binding, cargo receptor activity.

**Biological process:** receptor-mediated endocytosis, cobalamin metabolic process, cobalamin transport, Golgi to plasma membrane protein transport.

## Clinical significance {#significance}

**Uncertain significance** — review status Single submitter *(criteria provided, single submitter)*, last evaluated 2024-05-20.

**Submitter consensus:** unanimous (1/1 Uncertain significance).

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| Ambry Genetics | Uncertain significance | criteria provided, single submitter | clinical testing | 2024-05-20 |

## Associated conditions {#conditions}

[Inborn genetic diseases](https://sugi.bio/atlas/disease/inborn-genetic-diseases/).

**Reported phenotype names (ClinVar):** Inborn genetic diseases.

## Similar variants {#similar}

Related AMN variant pages (same residue, condition, or type): [AMN p.Ala238Thr](/variant/amn-p-ala238thr), [AMN p.Ala44Thr](/variant/amn-p-ala44thr), [AMN p.Arg271Trp](/variant/amn-p-arg271trp), [AMN p.Arg424Gly](/variant/amn-p-arg424gly), [AMN p.Cys250Trp](/variant/amn-p-cys250trp), [AMN p.Gln288His](/variant/amn-p-gln288his), [AMN p.Pro444Ser](/variant/amn-p-pro444ser), [AMN p.Ser437Asn](/variant/amn-p-ser437asn).

### 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 3293053). 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.*