SLC17A5

Chr 6AR

solute carrier family 17 member 5

Also known as: AST, ISSD, NSD, SD, SIALIN, SIASD, SLD, VEAT

This gene encodes a lysosomal membrane transporter that exports free sialic acid from lysosomes after it has been cleaved from cell surface glycoproteins and glycolipids. Biallelic loss-of-function mutations cause autosomal recessive sialic acid storage diseases, including the severe infantile form (infantile sialic acid storage disorder) and the milder adult-onset Salla disease. The pathogenic mechanism involves defective sialic acid transport leading to lysosomal accumulation of free sialic acid.

OMIMResearchSummary from RefSeq, OMIM, UniProt, Mechanism
LOFmechanismARLOEUF 1.042 OMIM phenotypes
Clinical SummarySLC17A5
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Gene-Disease Validity (ClinGen)
free sialic acid storage disease · 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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Clinical Trials
1 active or recruiting trial — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.04LOEUF
pLI 0.000
Z-score 1.39
OE 0.70 (0.481.04)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
0.71Z-score
OE missense 0.88 (0.790.98)
230 obs / 262.5 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.70 (0.481.04)
00.351.4
Missense OE0.88 (0.790.98)
00.61.4
Synonymous OE0.93
01.21.6
LoF obs/exp: 18 / 25.6Missense obs/exp: 230 / 262.5Syn Z: 0.57
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveSLC17A5-related Salla diseaseLOFAR

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

DN
0.80top 25%
GOF
0.7125th %ile
LOF
0.2191th %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

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

SLC17A5 · protein map & ClinVar variants

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

3D Protein StructureAlphaFold
Clinical Literature
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