Is COX10 p.Leu421Pro (c.1262T>C) pathogenic?

COX10 p.Leu421Pro (c.1262T>C) is classified Uncertain significance in COX10 (ClinVar, Multiple submitters, 2 submitters; last evaluated 2024-02-20). AlphaMissense: likely pathogenic (0.8594); Very rare (popmax 0.00167%, amr); Associated with mitochondrial complex IV deficiency, nuclear type 3.

What condition is associated with COX10 p.Leu421Pro (c.1262T>C)?

COX10 p.Leu421Pro (c.1262T>C) is associated with mitochondrial complex IV deficiency, nuclear type 3 (ClinVar).

How common is COX10 p.Leu421Pro (c.1262T>C) in the general population?

COX10 p.Leu421Pro (c.1262T>C) is very rare (popmax 0.00167%, amr) (gnomAD).

How is Isolated cytochrome C oxidase deficiency inherited?

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

What do computational predictors say about COX10 p.Leu421Pro (c.1262T>C)?

AlphaMissense predicts likely pathogenic (score 0.8594) — an in-silico prediction, not a clinical call.

COX10 p.Leu421Pro

c.1262T>C · rs149968861 · VCV2582510

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

AlphaMissense

likely pathogenic

0.8594 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00167%, amr)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

mitochondrial complex IV deficiency, nuclear type 3

Computational evidence

Protein change
AlphaMissense	0.8594	likely pathogenic
REVEL	0.775	moderately pathogenic-leaning
SaProt	LLR -15.15	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 7.7	GERP 1.4, phastCons 1
Regional constraint	o/e 0.89	unconstrained · MANE · 372 bp · p 0.13 · regional, not allelic
Overall
CADD	28.8	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean damaging — 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 0.00167% Admixed American · 1/59,986 alleles

Filtering AF 0.000803% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00065%

Overall 0.00118% 19/1,612,126 alleles · very rare

Ancestry group	Frequency	1 in
Remaining individualsnot grpmax-eligible	0.0032%	31,215
Admixed Americangrpmax	0.00167%	59,986
European (non-Finnish)	0.00136%	73,717

Remaining individuals 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: COX10
Protein: p.Leu421Pro
Coding: c.1262T>C
MANE Select: NM_001303
dbSNP: rs149968861
Type: single nucleotide variant
Location: chr17:14207143 (GRCh38)
Gene constraint: LOEUF 0.934 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 77.11

Full COX10 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

mitochondrial complex IV deficiency, nuclear type 3 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Isolated cytochrome C oxidase deficiency (Orphanet):

Inheritance: Autosomal recessive, Mitochondrial inheritance

Similar variants

COX10 p.Leu421= Likely benign ★ same residue
COX10 p.Asp336Val Pathogenic/Likely pathogenic ★★ same condition
COX10 p.Gln230Ter Likely pathogenic ★★ same condition
COX10 p.Pro225Leu Likely pathogenic ★★ same condition
COX10 c.-89G>C Uncertain significance ★★ same condition
COX10 c.-89G>T Uncertain significance ★★ same condition
COX10 p.Ala174Thr Uncertain significance ★★ ⚠ same condition
COX10 p.Ala175Val 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/cox10-p-leu421pro (accessed [today's date]).

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