Is BTD p.Leu135Pro (c.404T>C) pathogenic?

BTD p.Leu135Pro (c.404T>C) is classified Likely pathogenic in BTD (ClinVar, Multiple submitters, 2 submitters; last evaluated 2025-12-03). AlphaMissense: likely pathogenic (0.8552); Absent from gnomAD v4.1; Associated with biotinidase deficiency.

What condition is associated with BTD p.Leu135Pro (c.404T>C)?

BTD p.Leu135Pro (c.404T>C) is associated with biotinidase deficiency (ClinVar).

How common is BTD p.Leu135Pro (c.404T>C) in the general population?

BTD p.Leu135Pro (c.404T>C) is absent from gnomAD v4.1 (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.Leu135Pro (c.404T>C)?

AlphaMissense predicts likely pathogenic (score 0.8552) — an in-silico prediction, not a clinical call.

BTD p.Leu135Pro

c.404T>C · VCV3907157

Likely pathogenic Multiple submitters

Classification

Likely pathogenic

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

AlphaMissense

likely pathogenic

0.8552 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

biotinidase deficiency

Computational evidence

Protein change
AlphaMissense	0.8552	likely pathogenic ✓ concordant with ClinVar
REVEL	0.898	moderately pathogenic-leaning
SaProt	LLR -11.61	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 6.2	GERP 2.2, phastCons 1
Regional constraint	o/e 1.04	unconstrained · MANE · 10 kb · p 0.35 · regional, not allelic
Overall
CADD	28.6	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 L155P vs ClinVar L135P) — verify the residue.

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: BTD
Protein: p.Leu135Pro
Coding: c.404T>C
MANE Select: NM_001370658
Type: single nucleotide variant
Location: chr3:15644320 (GRCh38)
Gene constraint: LOEUF 1.22 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 86.77
Residue 135: 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.Leu135= Likely benign ★ 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-leu135pro (accessed [today's date]).

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