SDHD

Chr 11ARAD

succinate dehydrogenase complex subunit D

Also known as: CBT1, CII-4, CWS3, MC2DN3, PGL, PGL1, PPGL1, QPs3

The SDHD protein is a membrane-anchoring subunit of succinate dehydrogenase (complex II) that transfers electrons from succinate to ubiquinone in the mitochondrial electron transport chain. Mutations cause mitochondrial complex II deficiency (autosomal recessive inheritance) and pheochromocytoma/paraganglioma syndrome (autosomal dominant inheritance with paternal imprinting, meaning disease transmission occurs almost exclusively through the paternal allele). Loss of SDHD function leads to impaired cellular respiration and tumor formation through disrupted mitochondrial metabolism.

OMIMResearchSummary from RefSeq, OMIM, UniProt, Mechanism
MultiplemechanismAR/ADLOEUF 0.733 OMIM phenotypes
Clinical SummarySDHD
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Gene-Disease Validity (ClinGen)
mitochondrial disease · ARLimited

Limited evidence — not for standalone diagnostic reporting

2 total gene-disease associations curated

Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.23) despite low pLI — interpret in context.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.73LOEUF
pLI 0.337
Z-score 2.09
OE 0.23 (0.090.73)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
-0.17Z-score
OE missense 1.05 (0.891.25)
90 obs / 85.7 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios
LoF OE0.23 (0.090.73)
00.351.4
Missense OE1.05 (0.891.25)
00.61.4
Synonymous OE0.84
01.21.6
LoF obs/exp: 2 / 8.6Missense obs/exp: 90 / 85.7Syn Z: 0.75
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveSDHD-related pheochromocytomaGOFAD
limitedSDHD-related carcinoid tumors, intestinalOTHERAD
definitiveSDHD-related paragangliomas with or without deafnessLOFAD
DN
0.75top 25%
GOF
0.5954th %ile
LOF
0.3067th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and loss-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median
LOF1 literature citation

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Literature Evidence

LOFMutations in SDHD, a mitochondrial complex II gene, in hereditary paragangliomaPMID:10657297

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

SDHD · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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