Is B3GLCT p.Pro446= (c.1338G>A) pathogenic?

B3GLCT p.Pro446= (c.1338G>A) is classified Likely benign in B3GLCT (ClinVar, Single submitter, 1 submitter; last evaluated 2023-08-20). Very rare (popmax 0.0022%, sas); Associated with Peters plus syndrome.

What condition is associated with B3GLCT p.Pro446= (c.1338G>A)?

B3GLCT p.Pro446= (c.1338G>A) is associated with Peters plus syndrome (ClinVar).

How common is B3GLCT p.Pro446= (c.1338G>A) in the general population?

B3GLCT p.Pro446= (c.1338G>A) is very rare (popmax 0.0022%, sas) (gnomAD).

B3GLCT p.Pro446=

c.1338G>A · rs775690111 · VCV3009767

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.0022%, sas)

Conditions

Peters plus syndrome

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -5.6	GERP -4.1
Overall
CADD	2.795	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0022% South Asian · 2/91,078 alleles

Filtering AF 0.00145% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00123%

Overall 0.0018% 29/1,613,962 alleles · very rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.0022%	45,539
European (non-Finnish)	0.00212%	47,200
Remaining individualsnot grpmax-eligible	0.0016%	62,486
African / African-American	0.00134%	74,888

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: B3GLCT
Protein: p.Pro446=
Coding: c.1338G>A
MANE Select: NM_194318
dbSNP: rs775690111
Type: single nucleotide variant
Location: chr13:31329509 (GRCh38)
Gene constraint: LOEUF 1.109 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 86.94 · 1 PDB

Full B3GLCT gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Peters plus syndrome — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

B3GLCT p.Pro446Leu Uncertain significance ★ ⚠ same residue
B3GLCT c.459+1G>A Pathogenic/Likely pathogenic ★★ same condition
B3GLCT c.660+1G>A Pathogenic ★★ same condition
B3GLCT p.Tyr380Ter Pathogenic/Likely pathogenic ★★ same condition
B3GLCT c.*1752C>T Uncertain significance ★★ same condition
B3GLCT p.Arg377His Uncertain significance ★★ ⚠ same condition
B3GLCT p.Asn243Ser Uncertain significance ★★ ⚠ same condition
B3GLCT p.Asp469Asn 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/b3glct-p-pro446 (accessed [today's date]).

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