Is DBT p.Ala176= (c.528A>G) pathogenic?

DBT p.Ala176= (c.528A>G) is classified Likely benign in DBT (ClinVar, Single submitter, 1 submitter; last evaluated 2023-10-14). Very rare (popmax 0.0011%, sas); Associated with maple syrup urine disease.

What condition is associated with DBT p.Ala176= (c.528A>G)?

DBT p.Ala176= (c.528A>G) is associated with maple syrup urine disease (ClinVar).

How common is DBT p.Ala176= (c.528A>G) in the general population?

DBT p.Ala176= (c.528A>G) is very rare (popmax 0.0011%, sas) (gnomAD).

How is Maple syrup urine disease inherited?

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

DBT p.Ala176=

c.528A>G · rs753084031 · VCV2999875

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.0011%, sas)

Conditions

maple syrup urine disease

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -1.4	GERP -2, phastCons 0.001
Overall
CADD	7.629	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0011% South Asian · 1/91,084 alleles

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

Overall 0.000274% 4/1,461,796 alleles · very rare

Ancestry group	Frequency	1 in
Ashkenazi Jewishnot grpmax-eligible	0.00338%	29,600
South Asiangrpmax	0.0011%	91,084
European (non-Finnish)	0.000169%	589,984

Ashkenazi Jewish shows a higher raw frequency than the grpmax group above it. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and “Remaining individuals” — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

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.Ala176=
Coding: c.528A>G
MANE Select: NM_001918
dbSNP: rs753084031
Type: single nucleotide variant
Location: chr1:100218653 (GRCh38)
Gene constraint: LOEUF 1.255 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 78.71 · 5 PDB
Residue 176: the peripheral subunit-binding (psbd) domain; an α-helix

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

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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
DBT p.Arg301Cys Pathogenic/Likely pathogenic ★★ ⚠ same condition
DBT p.Arg376Cys 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/dbt-p-ala176 (accessed [today's date]).

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