Is BTD p.Ala279Val (c.836C>T) pathogenic?

BTD p.Ala279Val (c.836C>T) is classified Conflicting classifications of pathogenicity in BTD (ClinVar, Conflicting submitters, 2 submitters; last evaluated 2025-04-17). AlphaMissense: likely pathogenic (0.6041); Very rare (popmax 0.000169%, nfe); Associated with biotinidase deficiency.

What condition is associated with BTD p.Ala279Val (c.836C>T)?

BTD p.Ala279Val (c.836C>T) is associated with biotinidase deficiency (ClinVar).

How common is BTD p.Ala279Val (c.836C>T) in the general population?

BTD p.Ala279Val (c.836C>T) is very rare (popmax 0.000169%, nfe) (gnomAD).

How is Biotinidase deficiency inherited?

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

What do computational predictors say about BTD p.Ala279Val (c.836C>T)?

AlphaMissense predicts likely pathogenic (score 0.6041) — an in-silico prediction, not a clinical call.

BTD p.Ala279Val

c.836C>T · rs397514392 · VCV2734454

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 2 submitters

AlphaMissense

likely pathogenic

0.6041 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.000169%, nfe)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

biotinidase deficiency

Computational evidence

Protein change
AlphaMissense	0.6041	likely pathogenic
REVEL	0.708	pathogenic-leaning
SaProt	LLR -13.06	damaging
⇒ AlphaMissense, REVEL and SaProt all call this damaging.
Splicing
SpliceAI	<0.2	all four deltas below 0.2 · C>G here scores Δ0.63 · evaluated, not missing
Constraint at this position
Conservation	phyloP 5.9	GERP 2.3, phastCons 1
Regional constraint	o/e 1.04	unconstrained · MANE · 10 kb · p 0.35 · regional, not allelic
Overall
CADD	22.9	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

⚠ Isoform check: AlphaMissense numbered on a different transcript (AM A299V vs ClinVar A279V) — verify the residue.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000169% European (non-Finnish) · 2/1,180,032 alleles

Filtering AF 2.8e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 1.1e-05%

Overall 0.000137% 2/1,461,892 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: BTD
Protein: p.Ala279Val
Coding: c.836C>T
MANE Select: NM_001370658
dbSNP: rs397514392
Type: single nucleotide variant
Location: chr3:15644752 (GRCh38)
Gene constraint: LOEUF 1.22 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 86.77
Residue 279: the cn hydrolase domain

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

Disease context

biotinidase deficiency — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Biotinidase deficiency (Orphanet):

Inheritance: Autosomal recessive
Onset: Adolescent, Adult, Childhood, Infancy, Neonatal
Prevalence: 1-9 / 100 000 (Worldwide)

Similar variants

BTD p.Ala279Pro Pathogenic/Likely pathogenic ★★ same residue
BTD c.1330G>C Pathogenic ★★ same condition
BTD c.249+1G>T Likely pathogenic ★★ same condition
BTD c.400-2A>G Likely pathogenic ★★ same condition
BTD c.-17+2T>C Pathogenic/Likely pathogenic ★★ same condition
BTD p.Ala142Val Pathogenic/Likely pathogenic ★★ same condition
BTD p.Ala217Thr Pathogenic/Likely pathogenic ★★ ⚠ same condition
BTD p.Ala269Val Pathogenic/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/btd-p-ala279val (accessed [today's date]).

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