Is BBS4 p.Ala154Val (c.461C>T) pathogenic?

BBS4 p.Ala154Val (c.461C>T) is classified Uncertain significance in BBS4 (ClinVar, Single submitter, 1 submitter; last evaluated 2021-08-31). AlphaMissense: likely pathogenic (0.9528); Very rare (popmax 0.00203%, nfe); Associated with Bardet-Biedl syndrome.

What condition is associated with BBS4 p.Ala154Val (c.461C>T)?

BBS4 p.Ala154Val (c.461C>T) is associated with Bardet-Biedl syndrome (ClinVar).

How common is BBS4 p.Ala154Val (c.461C>T) in the general population?

BBS4 p.Ala154Val (c.461C>T) is very rare (popmax 0.00203%, 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 BBS4 p.Ala154Val (c.461C>T)?

AlphaMissense predicts likely pathogenic (score 0.9528) — an in-silico prediction, not a clinical call.

BBS4 p.Ala154Val

c.461C>T · rs756744863 · VCV939355

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.9528 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00203%, nfe)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

Bardet-Biedl syndrome

Computational evidence

Protein change
AlphaMissense	0.9528	likely pathogenic
REVEL	0.819	moderately pathogenic-leaning
SaProt	LLR -17.22	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 7.6	GERP 1.7, phastCons 1
Regional constraint	o/e 1.09	unconstrained · MANE · 51 kb · p 0.035 · regional, not allelic
Overall
CADD	33.0	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 0.00203% European (non-Finnish) · 24/1,179,864 alleles

Filtering AF 0.00138% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00116%

Overall 0.00149% 24/1,613,776 alleles · very rare

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: BBS4
Protein: p.Ala154Val
Coding: c.461C>T
MANE Select: NM_033028
dbSNP: rs756744863
Type: single nucleotide variant
Location: chr15:72724529 (GRCh38)
Gene constraint: LOEUF 0.953 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 78.36 · 1 PDB
Residue 154: the 'interaction with pcm1' region

Full BBS4 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

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

For Bardet-Biedl syndrome (Orphanet):

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

Similar variants

BBS4 c.1106+2T>A Pathogenic/Likely pathogenic ★★ same condition
BBS4 c.1248+1G>A Pathogenic/Likely pathogenic ★★ same condition
BBS4 c.1248+1G>T Pathogenic ★★ same condition
BBS4 c.1248+2T>C Pathogenic/Likely pathogenic ★★ same condition
BBS4 c.1249-2A>C Likely pathogenic ★★ same condition
BBS4 c.157-2A>G Pathogenic ★★ same condition
BBS4 c.157-3C>G Pathogenic ★★ same condition
BBS4 c.220+1G>C 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/bbs4-p-ala154val (accessed [today's date]).

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