Is DBT c.252-1G>T pathogenic?

DBT c.252-1G>T is classified Likely pathogenic in DBT (ClinVar, Single submitter, 1 submitter; last evaluated 2020-09-07). Absent from gnomAD v4.1; Associated with maple syrup urine disease.

What condition is associated with DBT c.252-1G>T?

DBT c.252-1G>T is associated with maple syrup urine disease (ClinVar).

How common is DBT c.252-1G>T in the general population?

DBT c.252-1G>T is absent from gnomAD v4.1 (gnomAD).

How is Maple syrup urine disease inherited?

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

DBT c.252-1G>T

rs1663522846 · VCV1066691

Likely pathogenic Single submitter

Classification

Likely pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

Consequence

canonical splice-site (±1/±2)

predicted LoF

gnomAD v4.1

Not reported

no allele count reported in gnomAD v4.1 (AN 1,563,720)

Conditions

maple syrup urine disease

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation/SpliceAI carries the signal.
Consequence	canonical splice-site (±1/±2)	predicted loss-of-function
Splicing
Splice region	acceptor -1	canonical splice dinucleotide (acceptor -1) · inside the BP7-excluded zone
SpliceAI	Δ1.00	acceptor loss · deltas
Pangolin	Δ0.90	loss · gain 0.70 · agrees with SpliceAI · independent
Constraint at this position
Conservation	phyloP 7.6	GERP 2.5, phastCons 1
Overall
CADD	34.0	PHRED · no single calibrated threshold — expert panels disagree

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

gnomAD v4.1 · exomes + genomes

No allele count reported in gnomAD v4.1 (AN 1,563,720). This is missing data, not an absence: the variant may or may not be present in gnomAD. Rarity (ACMG PM2) and BA1/BS1 cannot be assessed for it.

Variant & gene context

Gene: DBT
Coding: c.252-1G>T
MANE Select: NM_001918
dbSNP: rs1663522846
Type: single nucleotide variant
Location: chr1:100230915 (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 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
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-c-252-minus-1g-t (accessed [today's date]).

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