Is BFSP1 p.Ala220Thr (c.658G>A) pathogenic?

BFSP1 p.Ala220Thr (c.658G>A) is classified Uncertain significance in BFSP1 (ClinVar, Single submitter, 1 submitter; last evaluated 2023-12-25). AlphaMissense: likely benign (0.0808); Ultra-rare (popmax 0.0182%, sas); Associated with cataract 33.

What condition is associated with BFSP1 p.Ala220Thr (c.658G>A)?

BFSP1 p.Ala220Thr (c.658G>A) is associated with cataract 33 (ClinVar).

How common is BFSP1 p.Ala220Thr (c.658G>A) in the general population?

BFSP1 p.Ala220Thr (c.658G>A) is ultra-rare (popmax 0.0182%, sas) (gnomAD).

What do computational predictors say about BFSP1 p.Ala220Thr (c.658G>A)?

AlphaMissense predicts likely benign (score 0.0808) — an in-silico prediction, not a clinical call.

BFSP1 p.Ala220Thr

c.658G>A · rs763291516 · VCV2913521

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0808 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0182%, sas)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

cataract 33

Computational evidence

Protein change
AlphaMissense	0.0808	likely benign
REVEL	0.081	moderately benign-leaning
SaProt	LLR -6.45	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -0.97	GERP -5.5
Regional constraint	o/e 0.97	unconstrained · MANE · 37 kb · p 0.4 · regional, not allelic
Overall
CADD	13.09	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — 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 0.0182% South Asian · 16/88,100 alleles

Filtering AF 0.0113% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00927%

Overall 0.00219% 35/1,600,270 alleles · ultra-rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.0182%	5,506
Remaining individualsnot grpmax-eligible	0.00161%	61,924
European (non-Finnish)	0.00145%	69,086
African / African-American	0.00134%	74,528

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: BFSP1
Protein: p.Ala220Thr
Coding: c.658G>A
MANE Select: NM_001195
dbSNP: rs763291516
Type: single nucleotide variant
Location: chr20:17508966 (GRCh38)
Gene constraint: LOEUF 1.371 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 64.66
Residue 220: the if rod domain; the 'coil 2' region

Full BFSP1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

cataract 33 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

BFSP1 p.Ala643Thr Uncertain significance ★★ ⚠ same condition
BFSP1 p.Arg560Cys Uncertain significance ★★ ⚠ same condition
BFSP1 p.Arg69Trp Uncertain significance ★★ ⚠ same condition
BFSP1 p.Asp19Asn Uncertain significance ★★ ⚠ same condition
BFSP1 p.Gln294Arg Uncertain significance ★★ ⚠ same condition
BFSP1 p.Gly46Trp Uncertain significance ★★ ⚠ same condition
BFSP1 p.Ile271Thr Uncertain significance ★★ ⚠ same condition
BFSP1 p.Leu68Phe Uncertain significance ★★ ⚠ 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/bfsp1-p-ala220thr (accessed [today's date]).

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