Is BCOR p.Pro1277= (c.3831C>T) pathogenic?

BCOR p.Pro1277= (c.3831C>T) is classified Benign in BCOR (ClinVar, Single submitter, 1 submitter; last evaluated 2024-03-13). Ultra-rare (popmax 0.0546%, sas); Associated with microphthalmia, syndromic 2.

What condition is associated with BCOR p.Pro1277= (c.3831C>T)?

BCOR p.Pro1277= (c.3831C>T) is associated with microphthalmia, syndromic 2 (ClinVar).

How common is BCOR p.Pro1277= (c.3831C>T) in the general population?

BCOR p.Pro1277= (c.3831C>T) is ultra-rare (popmax 0.0546%, sas) (gnomAD).

BCOR p.Pro1277=

c.3831C>T · rs775358295 · VCV753795

Benign Single submitter

Classification

Benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

ultra-rare (popmax 0.0546%, sas)

Conditions

microphthalmia, syndromic 2

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 6.2	GERP 1.6, phastCons 1
Overall
CADD	9.013	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0546% South Asian · 31/56,780 alleles

Filtering AF 0.0395% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0343%

Overall 0.00256% 31/1,209,376 alleles · ultra-rare exomes 30/1,096,851 · genomes 1/112,525 · joint denominator

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: BCOR
Protein: p.Pro1277=
Coding: c.3831C>T
MANE Select: NM_001123385
dbSNP: rs775358295
Type: single nucleotide variant
Location: chrX:40063624 (GRCh38)
Structure: AlphaFold pLDDT 39.82 · 5 PDB
Residue 1277: the 'disordered' region

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

Disease context

microphthalmia, syndromic 2 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

BCOR p.Pro1277Ala Uncertain significance ★ ⚠ same residue
BCOR p.Arg1163Ter Pathogenic ★★ same condition
BCOR p.Arg1217Ter Pathogenic ★★ same condition
BCOR p.Arg1514Ter Pathogenic ★★ same condition
BCOR p.Arg342Ter Pathogenic ★★ same condition
BCOR p.Arg976Ter Pathogenic ★★ same condition
BCOR p.Ala1262Ser Uncertain significance ★★ ⚠ same condition
BCOR p.Ala1307Pro 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/bcor-p-pro1277 (accessed [today's date]).

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