Is SDHA p.Pro404Ser (c.1210C>T) pathogenic?

SDHA p.Pro404Ser (c.1210C>T) is classified Uncertain significance in SDHA (ClinVar, Multiple submitters, 2 submitters; last evaluated 2026-02-05). AlphaMissense: likely pathogenic (0.9946); Very rare (popmax 0.000763%, nfe); Associated with mitochondrial complex II deficiency, nuclear type 1.

What condition is associated with SDHA p.Pro404Ser (c.1210C>T)?

SDHA p.Pro404Ser (c.1210C>T) is associated with mitochondrial complex II deficiency, nuclear type 1, pheochromocytoma/paraganglioma syndrome 5, hereditary neoplastic syndrome (ClinVar).

How common is SDHA p.Pro404Ser (c.1210C>T) in the general population?

SDHA p.Pro404Ser (c.1210C>T) is very rare (popmax 0.000763%, nfe) (gnomAD).

How is Isolated succinate-CoQ reductase deficiency inherited?

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

What do computational predictors say about SDHA p.Pro404Ser (c.1210C>T)?

AlphaMissense predicts likely pathogenic (score 0.9946) — an in-silico prediction, not a clinical call.

SDHA p.Pro404Ser

c.1210C>T · rs769936006 · VCV1003229

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

AlphaMissense

likely pathogenic

0.9946 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.000763%, nfe)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

mitochondrial complex II deficiency, nuclear type 1

Computational evidence

Protein change
AlphaMissense	0.9946	likely pathogenic
REVEL	0.894	moderately pathogenic-leaning
SaProt	LLR -15.75	damaging
⇒ AlphaMissense, REVEL and SaProt all call this damaging.
Splicing
SpliceAI	<0.2	no splice effect predicted · four deltas, not one · how we know
Constraint at this position
Conservation	phyloP 7.6	GERP 1.8, phastCons 1
Regional constraint	o/e 0.76	unconstrained · MANE · 38 kb · p 1.1e-12 · regional, not allelic
Overall
CADD	22.6	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 0.000763% European (non-Finnish) · 9/1,180,024 alleles

Filtering AF 0.000359% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00026%

Overall 0.00118% 19/1,614,030 alleles · very rare exomes 18/1,461,876 · genomes 1/152,154 · joint denominator

Ancestry group	Frequency	1 in
Finnishnot grpmax-eligible	0.0141%	7,115
Remaining individualsnot grpmax-eligible	0.0016%	62,486
European (non-Finnish)grpmax	0.000763%	131,114

Finnish 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: SDHA
Protein: p.Pro404Ser
Coding: c.1210C>T
MANE Select: NM_004168
dbSNP: rs769936006
Type: single nucleotide variant
Location: chr5:235289 (GRCh38)
Gene constraint: LOEUF 0.786 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 94.06 · 5 PDB
Residue 404: a β-strand

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

Disease context

mitochondrial complex II deficiency, nuclear type 1 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: pheochromocytoma/paraganglioma syndrome 5 hereditary neoplastic syndrome

For Isolated succinate-CoQ reductase deficiency (Orphanet):

Inheritance: Autosomal recessive
Onset: Infancy, Neonatal

Similar variants

SDHA p.Pro404= Likely benign ★★ same residue
SDHA p.Pro404Leu Uncertain significance ★ ⚠ same residue
SDHA c.1064+1G>A Likely pathogenic ★★ same condition
SDHA c.1064+1G>T Likely pathogenic ★★ same condition
SDHA c.1064+2T>A Likely pathogenic ★★ same condition
SDHA c.1065-2A>G Likely pathogenic ★★ same condition
SDHA c.1260+1G>T Likely pathogenic ★★ same condition
SDHA c.1260+2T>A 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/sdha-p-pro404ser (accessed [today's date]).

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