SLC25A20

Chr 3AR

solute carrier family 25 member 20

Also known as: CAC, CACT

The protein mediates the transport of acylcarnitines across the mitochondrial inner membrane, enabling fatty acid beta-oxidation by translocating fatty acids into the mitochondrial matrix where they can be metabolized. Mutations cause carnitine-acylcarnitine translocase deficiency, an autosomal recessive disorder presenting in newborns and infants with hypoglycemia, cardiac arrest, hepatomegaly, hepatic dysfunction, and muscle weakness. This condition is typically lethal in the neonatal period and affects multiple organ systems dependent on fatty acid oxidation for energy.

GeneReviewsOMIMResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismARLOEUF 1.171 OMIM phenotype
Clinical SummarySLC25A20
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Gene-Disease Validity (ClinGen)
carnitine-acylcarnitine translocase deficiency · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
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ClinVar Variants
72 unique Pathogenic / Likely Pathogenic· 89 VUS of 300 total submissions
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GeneReview available — SLC25A20
Authoritative clinical overview · Recommended first read
Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.17LOEUF
pLI 0.000
Z-score 1.04
OE 0.73 (0.481.17)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
0.30Z-score
OE missense 0.93 (0.821.07)
152 obs / 163.0 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.73 (0.481.17)
00.351.4
Missense OE0.93 (0.821.07)
00.61.4
Synonymous OE0.88
01.21.6
LoF obs/exp: 13 / 17.7Missense obs/exp: 152 / 163.0Syn Z: 0.72
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveSLC25A20-related carnitine-acylcarnitine translocase deficiencyLOFAR

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

DN
0.79top 25%
GOF
0.6735th %ile
LOF
0.2968th %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

300 submitted variants in ClinVar

Classification Summary

Pathogenic32
Likely Pathogenic40
VUS89
Likely Benign131
Benign1
Conflicting4
32
Pathogenic
40
Likely Pathogenic
89
VUS
131
Likely Benign
1
Benign
4
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
19
2
11
0
32
Likely Pathogenic
30
6
4
0
40
VUS
1
76
11
1
89
Likely Benign
0
1
66
64
131
Benign
0
0
1
0
1
Conflicting
4
Total50859365297

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

View in ClinVar →

Protein Context — Lollipop Plot

SLC25A20 · 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.

Search ClinicalTrials.gov →
Clinical Literature
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