Is COL6A2 p.Ser683Phe (c.2048C>T) pathogenic?

COL6A2 p.Ser683Phe (c.2048C>T) is classified Uncertain significance in COL6A2 (ClinVar, Multiple submitters, 2 submitters; last evaluated 2023-09-08). AlphaMissense: likely pathogenic (0.6575); Very rare (popmax 0.000339%, nfe); Associated with Bethlem myopathy 1A.

What condition is associated with COL6A2 p.Ser683Phe (c.2048C>T)?

COL6A2 p.Ser683Phe (c.2048C>T) is associated with Bethlem myopathy 1A (ClinVar).

How common is COL6A2 p.Ser683Phe (c.2048C>T) in the general population?

COL6A2 p.Ser683Phe (c.2048C>T) is very rare (popmax 0.000339%, nfe) (gnomAD).

How is Bethlem muscular dystrophy inherited?

Typically Autosomal dominant, Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

What do computational predictors say about COL6A2 p.Ser683Phe (c.2048C>T)?

AlphaMissense predicts likely pathogenic (score 0.6575) — an in-silico prediction, not a clinical call.

COL6A2 p.Ser683Phe

c.2048C>T · rs1258904789 · VCV450934

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

AlphaMissense

likely pathogenic

0.6575 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.000339%, nfe)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

Bethlem myopathy 1A

Computational evidence

Protein change
AlphaMissense	0.6575	likely pathogenic
REVEL	0.829	moderately pathogenic-leaning
SaProt	LLR -11.47	damaging
⇒ AlphaMissense, REVEL and SaProt all call this damaging.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 3.2	GERP 1.4, phastCons 1
Regional constraint	o/e 1.16	unconstrained · MANE · 16 kb · p 1.4e-07 · regional, not allelic
Overall
CADD	27.1	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean damaging — a triage signal, not a reclassification

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000339% European (non-Finnish) · 4/1,180,004 alleles

Filtering AF 7.9e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 5.4e-05%

Overall 0.000342% 5/1,460,874 alleles · very rare

Ancestry group	Frequency	1 in
Finnishnot grpmax-eligible	0.00159%	63,070
European (non-Finnish)grpmax	0.000339%	295,001

Finnish shows a higher raw frequency than the grpmax group above it. 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.

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: COL6A2
Protein: p.Ser683Phe
Coding: c.2048C>T
MANE Select: NM_001849
dbSNP: rs1258904789
Type: single nucleotide variant
Location: chr21:46125863 (GRCh38)
Gene constraint: LOEUF 0.895 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 69.58 · 1 PDB
Residue 683: the vwfa 2 domain; the 'nonhelical region' region

Full COL6A2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Bethlem myopathy 1A — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Bethlem muscular dystrophy (Orphanet):

Inheritance: Autosomal dominant, Autosomal recessive
Onset: Childhood, Infancy
Prevalence: 1-9 / 1 000 000 (United Kingdom)

Similar variants

COL6A2 p.Ser683Pro Uncertain significance ★ ⚠ same residue
COL6A2 c.1000-1G>T Pathogenic ★★ same condition
COL6A2 c.1000-2A>C Pathogenic ★★ same condition
COL6A2 c.1053+1G>A Pathogenic ★★ same condition
COL6A2 c.1053+1G>C Pathogenic/Likely pathogenic ★★ same condition
COL6A2 c.1053+2T>C Pathogenic/Likely pathogenic ★★ same condition
COL6A2 c.1054-2A>G Pathogenic/Likely pathogenic ★★ same condition
COL6A2 c.115+2T>C Pathogenic/Likely pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/col6a2-p-ser683phe (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown