# NM_000014.6(A2M):c.1920A>C (p.Glu640Asp)

https://sugi.bio/variant/a2m-p-glu640asp

## Summary

**A2M p.Glu640Asp (c.1920A>C)** is classified **Uncertain significance** in A2M (ClinVar, Single submitter, 1 submitter; last evaluated 2025-08-12). AlphaMissense: likely benign (0.0886); Absent from gnomAD v4.1.

**At a glance:** Uncertain significance · review: Single submitter · 1 submitter · AlphaMissense likely benign · absent from gnomAD v4.1

## For patients & families {#patients}

This is a change in the A2M gene that is currently of uncertain significance — a definitive interpretation has not yet been established, 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 | [A2M](https://sugi.bio/atlas/gene/A2M/) |
| Protein change (HGVS p.) | p.Glu640Asp |
| Coding change (HGVS c.) | c.1920A>C |
| MANE Select transcript | [NM_005810](https://www.ncbi.nlm.nih.gov/nuccore/NM_005810) (variant reported on NM_000014) |
| Variant type | single nucleotide variant |
| Location | chr12:9095632-9095632 (GRCh38) |
| ClinVar | [VCV4221248](https://www.ncbi.nlm.nih.gov/clinvar/variation/4221248/) |

**All HGVS expressions:** `LRG_591:g.25331A>C`, `LRG_591t1:c.1920A>C`, `NC_000012.11:g.9248228T>G`, `NC_000012.12:g.9095632T>G`, `NG_011717.2:g.25331A>C`, `NM_000014.6:c.1920A>C`, `NM_001347423.2:c.1920A>C`, `NM_001347424.2:c.1620A>C`, `NM_001347425.2:c.1470A>C`

## Computational & population evidence {#evidence}

**Concordance:** ClinVar classifies this **uncertain**; the computational predictors unanimously lean **tolerated** — a triage signal, not a reclassification.

- AlphaMissense **likely benign** (0.0886)
- REVEL 0.042 (moderately benign-leaning) — agrees with AlphaMissense
- SaProt LLR -5.664 (tolerated) — agrees with AlphaMissense
- → **In-silico consensus:** AlphaMissense, REVEL and SaProt all call this tolerated
- Conservation: phyloP -0.081, GERP -1.72 — not a conserved position (phyloP < 0.1, ACGS BP7 cut)
- CADD: **PHRED 7.509**. 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 0.84** across the covering region of the MANE Select transcript (9,067,826–9,115,849), spanning 48,023 bp. Chi-square p 4.5e-12. Describes the region, not this allele; gnomAD v4.1.1's own constrained determination. *Descriptive; no ACMG code applied.*
- SpliceAI: **not looked up on this page** — it was served without the gene's SpliceAI index, so no lookup was made. This is a gap in this page, not in the data, and says nothing about whether a splicing effect is predicted.
- Population frequency: **absent from gnomAD v4.1** — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

*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.*

## Clinical significance {#significance}

**Uncertain significance** — review status Single submitter *(criteria provided, single submitter)*, last evaluated 2025-08-12.

**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 | 2025-08-12 |

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

### 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 4221248). 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.*