SDHAF1

Chr 19AR

succinate dehydrogenase complex assembly factor 1

Also known as: LYRM8, MC2DN2

The protein resides in the mitochondrial matrix and is essential for assembly of the succinate dehydrogenase (SDH) complex II of the mitochondrial respiratory chain, though it does not physically associate with the assembled complex. Mutations cause mitochondrial complex II deficiency (also called SDH-defective infantile leukoencephalopathy) through an autosomal recessive inheritance pattern. The pathogenic mechanism involves loss of function, preventing proper assembly of the SDH complex required for mitochondrial respiration.

OMIMResearchSummary from RefSeq, OMIM, UniProt, Mechanism
MultiplemechanismARLOEUF 1.901 OMIM phenotype
Clinical SummarySDHAF1
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Gene-Disease Validity (ClinGen)
Leigh syndrome · ARLimited

Limited evidence — not for standalone diagnostic reporting

2 total gene-disease associations curated

Population Constraint (gnomAD)
Low constraint (pLI 0.09) — loss-of-function variants are relatively tolerated in the population.
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ClinVar Variants
19 unique Pathogenic / Likely Pathogenic· 61 VUS of 107 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.90LOEUF
pLI 0.087
Z-score -0.09
OE 1.11 (0.281.90)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
0.38Z-score
OE missense 0.86 (0.681.09)
49 obs / 57.1 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE1.11 (0.281.90)
00.351.4
Missense OE0.86 (0.681.09)
00.61.4
Synonymous OE0.77
01.21.6
LoF obs/exp: 1 / 0.9Missense obs/exp: 49 / 57.1Syn Z: 0.94
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveSDHAF1-related mitochondrial complex II deficiencyOTHERAR

Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.

DN
0.73top 25%
GOF
0.6932th %ile
LOF
0.3162th %ile

The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.

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

ClinVar Variant Classifications

107 submitted variants in ClinVar

Classification Summary

Pathogenic16
Likely Pathogenic3
VUS61
Likely Benign20
Benign4
Conflicting3
16
Pathogenic
3
Likely Pathogenic
61
VUS
20
Likely Benign
4
Benign
3
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
1
3
12
0
16
Likely Pathogenic
2
1
0
0
3
VUS
0
44
16
1
61
Likely Benign
0
1
4
15
20
Benign
0
1
3
0
4
Conflicting
3
Total3503516107

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

SDHAF1 · 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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