Is BBS2 p.Thr276Ser (c.827C>G) pathogenic?

BBS2 p.Thr276Ser (c.827C>G) is classified Uncertain significance in BBS2 (ClinVar, Multiple submitters, 3 submitters; last evaluated 2024-02-13). AlphaMissense: likely benign (0.1587); Very rare (popmax 0.00297%, nfe); Associated with Bardet-Biedl syndrome 2.

What condition is associated with BBS2 p.Thr276Ser (c.827C>G)?

BBS2 p.Thr276Ser (c.827C>G) is associated with Bardet-Biedl syndrome 2, retinitis pigmentosa 74 (ClinVar).

How common is BBS2 p.Thr276Ser (c.827C>G) in the general population?

BBS2 p.Thr276Ser (c.827C>G) is very rare (popmax 0.00297%, nfe) (gnomAD).

How is Bardet-Biedl syndrome inherited?

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

What do computational predictors say about BBS2 p.Thr276Ser (c.827C>G)?

AlphaMissense predicts likely benign (score 0.1587) — an in-silico prediction, not a clinical call.

BBS2 p.Thr276Ser

c.827C>G · rs776282237 · VCV1315297

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

AlphaMissense

likely benign

0.1587 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00297%, nfe)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

Bardet-Biedl syndrome 2

Computational evidence

Protein change
AlphaMissense	0.1587	likely benign
REVEL	0.253	benign-leaning
SaProt	LLR -6.70	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 7.6	GERP 1.1, phastCons 1
Regional constraint	o/e 0.87	unconstrained · MANE · 35 kb · p 9.6e-05 · regional, not allelic
Overall
CADD	21.3	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 0.00297% European (non-Finnish) · 35/1,180,032 alleles

Filtering AF 0.00215% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00191%

Overall 0.00223% 36/1,614,024 alleles · very rare

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.00297%	33,715
Remaining individualsnot grpmax-eligible	0.0016%	62,484

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: BBS2
Protein: p.Thr276Ser
Coding: c.827C>G
MANE Select: NM_031885
dbSNP: rs776282237
Type: single nucleotide variant
Location: chr16:56502786 (GRCh38)
Gene constraint: LOEUF 0.892 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 89.49

Full BBS2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Bardet-Biedl syndrome 2 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: retinitis pigmentosa 74

For Bardet-Biedl syndrome (Orphanet):

Inheritance: Autosomal recessive, Oligogenic
Onset: Antenatal, Childhood, Infancy, Neonatal
Prevalence: 1-9 / 100 000 (Specific population)

Similar variants

BBS2 c.118-1G>T Likely pathogenic ★★ same condition
BBS2 c.118-2A>C Likely pathogenic ★★ same condition
BBS2 c.118-2A>G Likely pathogenic ★★ same condition
BBS2 c.1225+2T>C Likely pathogenic ★★ same condition
BBS2 c.1225+2T>G Likely pathogenic ★★ same condition
BBS2 c.1397+1G>A Pathogenic/Likely pathogenic ★★ same condition
BBS2 c.1397+2T>C Likely pathogenic ★★ same condition
BBS2 c.1398-2A>G 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/bbs2-p-thr276ser (accessed [today's date]).

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