Is DBT p.Arg12Ser (c.36G>C) pathogenic?

DBT p.Arg12Ser (c.36G>C) is classified Uncertain significance in DBT (ClinVar, Multiple submitters, 2 submitters; last evaluated 2022-07-05). AlphaMissense: likely benign (0.2127); Ultra-rare (popmax 0.0213%, afr); Associated with maple syrup urine disease.

What condition is associated with DBT p.Arg12Ser (c.36G>C)?

DBT p.Arg12Ser (c.36G>C) is associated with maple syrup urine disease (ClinVar).

How common is DBT p.Arg12Ser (c.36G>C) in the general population?

DBT p.Arg12Ser (c.36G>C) is ultra-rare (popmax 0.0213%, afr) (gnomAD).

How is Maple syrup urine disease inherited?

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

What do computational predictors say about DBT p.Arg12Ser (c.36G>C)?

AlphaMissense predicts likely benign (score 0.2127) — an in-silico prediction, not a clinical call.

DBT p.Arg12Ser

c.36G>C · rs147775797 · VCV2143942

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

AlphaMissense

likely benign

0.2127 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0213%, afr)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

maple syrup urine disease

Computational evidence

Protein change
AlphaMissense	0.2127	likely benign
REVEL	0.035	moderately benign-leaning
SaProt	LLR -6.92	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	<0.2	no splice effect predicted · four deltas, not one · how we know
Constraint at this position
Conservation	phyloP -0.36	GERP -2.4
Regional constraint	o/e 0.88	unconstrained · MANE · 54 kb · p 0.0036 · regional, not allelic
Overall
CADD	16.09	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 0.0213% African / African-American · 16/74,942 alleles

Filtering AF 0.0133% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0109%

Overall 0.00112% 18/1,614,112 alleles · ultra-rare exomes 10/1,461,874 · genomes 8/152,238 · joint denominator

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.0213%	4,684
Admixed American	0.00167%	60,008
Remaining individualsnot grpmax-eligible	0.0016%	62,490

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: DBT
Protein: p.Arg12Ser
Coding: c.36G>C
MANE Select: NM_001918
dbSNP: rs147775797
Type: single nucleotide variant
Location: chr1:100249785 (GRCh38)
Gene constraint: LOEUF 1.255 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 78.71 · 5 PDB

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

Disease context

maple syrup urine disease — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Maple syrup urine disease (Orphanet):

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

Similar variants

DBT p.Arg12Gly Uncertain significance ★★ ⚠ same residue
DBT p.Arg12= Likely benign ★ same residue
DBT c.1018-550A>G Pathogenic/Likely pathogenic ★★ same condition
DBT c.1281+1G>A Pathogenic/Likely pathogenic ★★ same condition
DBT c.1281+1G>T Pathogenic/Likely pathogenic ★★ same condition
DBT c.51+1G>T Pathogenic/Likely pathogenic ★★ same condition
DBT c.52-1G>A Pathogenic/Likely pathogenic ★★ same condition
DBT p.Arg291Ter 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/dbt-p-arg12ser (accessed [today's date]).

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