Is SUCLA2 p.Pro403= (c.1209T>A) pathogenic?

SUCLA2 p.Pro403= (c.1209T>A) is classified Likely benign in SUCLA2 (ClinVar, Single submitter, 1 submitter; last evaluated 2023-02-21). Absent from gnomAD v4.1; Associated with mitochondrial DNA depletion syndrome, encephalomyopathic form with methylmalonic aciduria.

How common is SUCLA2 p.Pro403= (c.1209T>A) in the general population?

SUCLA2 p.Pro403= (c.1209T>A) is absent from gnomAD v4.1 (gnomAD).

SUCLA2 p.Pro403=

Q: What condition is associated with SUCLA2 p.Pro403= (c.1209T>A)?

SUCLA2 p.Pro403= (c.1209T>A) is associated with mitochondrial DNA depletion syndrome, encephalomyopathic form with methylmalonic aciduria (ClinVar).

Q: How is Mitochondrial DNA depletion syndrome, encephalomyopathic form with methylmalonic aciduria inherited?

Typically Mitochondrial inheritance (Orphanet). A genetic counselor can assess individual risk for a family.

c.1209T>A · rs2541668691 · VCV2780163

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

mitochondrial DNA depletion syndrome, encephalomyopathic form with methylmalonic aciduria

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 3	GERP -4.5, phastCons 1
Overall
CADD	8.656	PHRED · no single calibrated threshold — expert panels disagree

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: SUCLA2
Protein: p.Pro403=
Coding: c.1209T>A
MANE Select: NM_003850
dbSNP: rs2541668691
Type: single nucleotide variant
Location: chr13:47949502 (GRCh38)
Gene constraint: LOEUF 0.713 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 87.45 · 2 PDB

Full SUCLA2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

mitochondrial DNA depletion syndrome, encephalomyopathic form with methylmalonic aciduria — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Mitochondrial DNA depletion syndrome, encephalomyopathic form with methylmalonic aciduria (Orphanet):

Inheritance: Mitochondrial inheritance
Onset: Infancy

Similar variants

SUCLA2 c.534+1G>A Pathogenic ★★ same condition
SUCLA2 p.Ala307Val Pathogenic/Likely pathogenic ★★ ⚠ same condition
SUCLA2 p.Arg160Ter Pathogenic/Likely pathogenic ★★ same condition
SUCLA2 p.Arg284Cys Pathogenic/Likely pathogenic ★★ same condition
SUCLA2 p.Asp333Gly Pathogenic/Likely pathogenic ★★ same condition
SUCLA2 p.Ala12Val Uncertain significance ★★ ⚠ same condition
SUCLA2 p.Ala27Val Uncertain significance ★★ ⚠ same condition
SUCLA2 p.Ala330Pro Uncertain significance ★★ ⚠ 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/sucla2-p-pro403 (accessed [today's date]).

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