Is SDHA p.Ala76= (c.228T>G) pathogenic?

SDHA p.Ala76= (c.228T>G) is classified Benign/Likely benign in SDHA (ClinVar, Multiple submitters, 3 submitters; last evaluated 2025-08-10). Very rare (popmax 0.00119%, nfe); Associated with pheochromocytoma/paraganglioma syndrome 5.

What condition is associated with SDHA p.Ala76= (c.228T>G)?

SDHA p.Ala76= (c.228T>G) is associated with pheochromocytoma/paraganglioma syndrome 5, hereditary neoplastic syndrome, mitochondrial complex II deficiency, nuclear type 1 (ClinVar).

How common is SDHA p.Ala76= (c.228T>G) in the general population?

SDHA p.Ala76= (c.228T>G) is very rare (popmax 0.00119%, nfe) (gnomAD).

SDHA p.Ala76=

c.228T>G · rs1416043203 · VCV1101077

Benign/Likely benign Multiple submitters

Classification

Benign/Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

gnomAD v4.1

Rare

very rare (popmax 0.00119%, nfe)

Conditions

pheochromocytoma/paraganglioma syndrome 5

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	<0.2	no splice effect predicted · four deltas, not one · how we know
Constraint at this position
Conservation	phyloP -2.7	GERP 0.72
Overall
CADD	8.419	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00119% European (non-Finnish) · 14/1,179,852 alleles

Filtering AF 0.000689% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000539%

Overall 0.000868% 14/1,613,620 alleles · very rare exomes 12/1,461,370 · genomes 2/152,250 · joint denominator

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.Ala76=
Coding: c.228T>G
MANE Select: NM_004168
dbSNP: rs1416043203
Type: single nucleotide variant
Location: chr5:224437 (GRCh38)
Gene constraint: LOEUF 0.786 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 94.06 · 5 PDB
Residue 76: an α-helix

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

Disease context

pheochromocytoma/paraganglioma syndrome 5 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: hereditary neoplastic syndrome mitochondrial complex II deficiency, nuclear type 1

Similar variants

SDHA p.Ala76Gly Uncertain significance ★ ⚠ same residue
SDHA p.Ala76Val 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-ala76 (accessed [today's date]).

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